Supraglottic Airway Devices

Quick Answer

Supraglottic airway devices (SGAs) are extraglottic devices that seal the laryngeal inlet to provide oxygenation and ventilation without entering the trachea. Second-generation devices (LMA Supreme, i-gel, LMA Protector) with gastric access ports provide higher seal pressures and reduce aspiration risk. SGAs serve as rescue devices in "can't intubate, can't oxygenate" (CICO) scenarios and as primary airways for selected emergency cases. Proper sizing based on weight, correct insertion technique, and capnographic confirmation are essential for safe use. ANZCOR and Australian Resuscitation Council guidelines recommend SGAs as second-line airways when bag-valve-mask ventilation is inadequate and endotracheal intubation is unattainable or unsuccessful [1,2].

ACEM Exam Focus

Primary Exam: Know anatomical landmarks (epiglottis, vallecula, arytenoids, piriform fossae), understand SGA pressure dynamics, and compare SGA efficacy to endotracheal intubation. Understand gastric suction capability differences between generations.

Fellowship Written: Expected to list indications, contraindications, sizing, insertion steps, success factors, complications, and SGA versus ETT decision-making. Must know ANZCOR Guideline 9.2 (and 4.4 for OCA) recommendations, specific success rates in hands of trained providers, and evidence comparing first- versus second-generation devices.

OSCE: Common stations include failed RSI requiring SGA insertion, SGA troubleshooting, and managing a patient with SGA in situ. Examiners assess correct sizing, insertion technique, confirmation of placement, secure fixation, and management of complications.

Viva: Candidates may be asked to discuss SGA as part of difficult airway algorithms, compare device types, explain gastric access mechanisms, describe complications, and justify SGA use in particular clinical scenarios.

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Key Points

• Second-generation SGAs (LMA Supreme, i-gel, LMA Protector) feature gastric access ports and higher seal pressures [3]
• Size selection based on weight: 1 (0-5kg), 2 (5-10kg), 2.5 (10-20kg), 3 (20-30kg), 4 (30-50kg or 50-70kg), 5 (70kg+) for LMAs; i-gel sizing uses similar weight ranges [4]
• Cuff inflation volumes: 50-70% of maximum recommended volume; avoid overinflation as it worsens seal [5]
• Confirmation requires chest rise + bilateral breath sounds + capnography waveform [6]
• First-pass success rate: 85-95% when performed by experienced providers [7]
• Peak airway pressures: LMA Classic ~20-25 cmH2O; second-generation 25-30 cmH2O; above these pressures cause leak [8]
• CICO scenarios: SGA recommended before cricothyroidotomy when face-to-airway possible per ANZCOR 4.4 [9]

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Types of Supraglottic Airway Devices

First-Generation Devices

LMA Classic: Original reusable device with aperture bars preventing epiglottic downfolding. Basic design without gastric access. Seal pressure 20-25 cmH2O. Lower first-pass success than second-generation due to epiglottic obstruction risk. Used as airway adjunct in resuscitation and peri-arrest settings.

LMA Unique and LMA Flexible: Disposable versions of Classic design. LMA Flexible has reinforced tube for head/neck procedures (dental surgery, otolaryngology). Both lack gastric access. Limited use in emergency due to lower seal pressures and no gastric drainage.

Combitube: Esophageal-tracheal double-lumen device designed for pre-hospital use. Complex insertion (blind tube placement). Can ventilate via either tracheal or oesophageal lumen depending on placement. High complication rate largely superseded by second-generation SGAs.

EasyTube: Similar to Combitube but with distal cuff that can be inflated in tube to prevent epiglottic obstruction. Simpler than Combitube but still less intuitive than modern SGAs. Largely replaced by i-gel and LMA Supreme in Australian EDs.

Second-Generation Devices

LMA Supreme: Single-use device with anatomically curved tube, integrated bite block, and gastric drainage port running parallel to main airway lumen. Allows gastric decompression and reduces aspiration risk. Cuff volume 30-40mL (size 4-5). Seal pressure 25-30 cmH2O. Recommended for emergency use by ANZCOR.

i-gel: Thermoplastic elastomer cuff that moulds to patient anatomy at body temperature without inflation. No cuff inflation required (ready for immediate use). Gastric channel allows suction. Highest success rates reported across studies. Preferred device in many Australian EDs and pre-hospital services. Seal pressure 25-30 cmH2O.

LMA Protector: Second-generation device with integrated gastric access, higher seal pressure (30+ cmH2O), and reinforced bite block. Designed specifically for emergency and pre-hospital settings. Features removable connector to maintain sterility. Available in Australia.

AuraGain: Pre-filled curved silicone cuff with gastric channel. Higher first-pass success rate. Features integrated suction catheter and fiberoptic port. Not commonly used in Australian emergency medicine but available in some institutions.

Ambu AuraOnce: Single-use SGA with gastric channel. Similar features to LMA Supreme but with different cuff design. Some Australian services use this as primary SGA.

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Sizing

LMA Supreme/i-gel Size Guide

Emergency SGA Placement Procedure: Step-by-Step

1. Preparation

• Check equipment: Confirm SGA intact (no cuff leaks), cuff fully deflated, lubricant available
• Size selection: Use weight-based sizing; err toward larger size for better seal
• Preoxygenation: 100% O2 via bag-valve-mask for 3-5 minutes or 8 vital capacity breaths
• Anaesthesia depth: Ensure patient has absent gag reflex (cardiac arrest = automatic; others require adequate sedation ± paralysis)
• Positioning: Sniffing position if C-spine not unstable; maintain neutral alignment if C-spine injury suspected
• Monitoring: Pulse oximetry, capnography available, suction ready

2. Technique

LMA Supreme/LMA Classic insertion:

1. Hold device at tube-cuff junction like a pen
2. Deflate cuff completely (press against flat surface during deflation)
3. Lubricate posterior surface ONLY (thin layer water-soluble gel)
4. Open mouth using non-dominant hand (chin lift or crossed-fingers)
5. Place deflated cuff against hard palate just behind upper incisors
6. Keep posterior surface pressed firmly against hard/soft palate during insertion
7. Use index finger (in V-notch) to guide device along palate into hypopharynx
8. Advance until definite resistance (encountering upper oesophageal sphincter)
9. Remove finger before cuff inflation
10. Inflate cuff to 50-70% of maximum volume with syringe
11. Observe 1-2 cm outward migration during inflation (normal)

i-gel insertion:

1. No cuff inflation required (already correctly sized)
2. Lubricate posterior surface
3. Insert as above (hold at tube-cuff junction, press against palate)
4. Advance to resistance
5. Remove finger, immediately connect to circuit (no inflation step)
6. Secure device

3. Confirmation

• Chest rise: Symmetrical bilaterally
• Auscultation: Breath sounds clear bilaterally, no gastric sounds
• Capnography: Waveform present (ETCO2 35-45 mmHg normal)
• Oxygenation: SpO2 ≥94% (or ≥90% if cardiac arrest)
• Leak test: Squeeze BVM, listen for escaping air around mask
• Gastric suction: If available, pass suction through gastric port; confirm gastric access

4. Securing

• Fix tube at corner of mouth with tape or commercial holder
• Prevent rotation and outward displacement
• Place bite block if not integrated (LMA Classic) - DO NOT bite the tube
• Document depth at teeth/lips

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Indications

Primary Indications

• CICO scenario: Face-to-airway possible but both ETT and bag-valve-mask have failed (recommended by ANZCOR 4.4) [9]
• Failed RSI: Multiple intubation attempts unsuccessful, hypoxia developing, SGA provides oxygenation while reconsidering options
• Cardiac arrest: When bag-valve-mask ventilation inadequate and intubation delayed or unavailable
• Pre-hospital limited airway skills: Paramedics unable to perform endotracheal intubation can use SGAs (common in NSW Ambulance, QAS, SAS) [10]
• Short procedural sedation: When rapid recovery needed and patient fasted
• Airway adjunct during difficult bag-valve-mask: Facilitates hands-free ventilation

Relative Indications (context-dependent)

• Known difficult airway: When ETT unlikely to succeed and procedure time-sensitive (e.g., obstetric crisis, acute deterioration)
• Limited resources: When neuromuscular blockade unavailable for RSI or suction equipment limited
• Prolonged field time: Retrieval scenarios where SGA provides more stable airway than bag-valve-mask during transport
• Facial trauma: When mask seal poor with bag-valve-mask but oral route accessible
• Obesity: When bag-valve-mask mask seal challenging but airway anatomy favourable
• Training context: Supervised learning for junior doctors performing RSI

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Contraindications

Absolute Contraindications

• Mouth opening < 20 mm: Cannot physically insert device (alternative: front-of-neck access)
• Complete upper airway obstruction: Device cannot reach laryngeal inlet (e.g., massive angioedema, supraglottic tumour near larynx)
• Distorted anatomy preventing placement: Massive facial trauma making oral route impossible
• Valid DNACPR or advance directive: Patient declines airway management

Relative Contraindications

• High aspiration risk: Full stomach, active vomiting, active upper GI bleeding, bowel obstruction, pregnancy beyond 10 weeks, obesity, ileus (balance against hypoxia risk)
• Need for high pressure ventilation: ARDS, COPD with air trapping, high airway resistance (SGA may leak)
• Prolonged ventilation needed: ETT provides better protection and pressure maintenance; SGA limited to hours
• Gastric distension risk expected: Multi-disease trauma with potential for delayed surgery
• Known difficult SGA insertion: Prior documented failures or anatomical extremes
• Patients likely to bite down: Need bite block; not all devices have integrated protection
• Radiologic investigations requiring MRI: Metallic component in some SGAs (check device MRI compatibility)

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Success Factors and Complications

First-Pass Success Factors

• Proper sizing: Larger size typically better seal when between categories
• Adequate lubrication: Prevents tissue trauma and facilitates passage
• Correct technique: Posterior surface pressed firmly against palate throughout insertion
• Patient positioning: Sniffing position improves success (if C-spine allows)
• Anaesthesia depth: Prevents laryngospasm or movement
• Operator experience: Training correlates with success rates

Common Complications

Aspiration risk: Reduced from 0.5-2% (first-generation) to below 0.5% (second-generation) due to gastric access and higher seal pressures. Still higher than ETT. Contra-indicated for high-risk aspiration scenarios unless hypoxia demands SGA use.

Laryngospasm: Triggered by inadequate anaesthesia depth. Treat with deepening anaesthesia (propofol 1 mg/kg) and positive pressure ventilation. May require suxamethonium 1 mg/kg if severe.

Gastric insufflation: Prevented by correct cuff inflation (50-70% volume), correct sizing, and gastric decompression (via port in second-generation devices). Manage by gastric suction via catheter.

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Troubleshooting

Scenario 1: No Chest Rise or Breath Sounds

Causes: Malposition (epiglottic downfolding), cuff underinflated, cuff overinflated, wrong size, patient biting tube

Management:

1. Squeeze BVM: Listen for air leak around mask
2. Inflate cuff additional 5-10 mL (if not already overinflated)
3. Reposition: Rotate tube 90 degrees, lift patient jaw slightly
4. Check tube not kinked or biting
5. Remove and reinsert SGA
6. Consider alternative: Bag-valve-mask, endotracheal intubation, cricothyroidotomy

Scenario 2: Gastric Insufflation

Causes: Overinflation of cuff, high inspiratory pressures, device malposition

Management:

1. Pass gastric suction via port (if available)
2. Reduce inspiratory volume/pressure
3. Confirm cuff not overinflated
4. If persistent: remove SGA, reinsert after gastric decompression, consider ETT

Scenario 3: Inadequate Seal with Air Leak

Causes: Wrong size, cuff underinflated, patient positioning suboptimal, device not fully seated

Management:

1. Reinflate cuff incrementally
2. Reposition patient (neck extension vs flexion)
3. Consider larger size if possible
4. Reinsert device if malposition suspected
5. If still inadequate: Convert to ETT or consider alternative airway

Scenario 4: Epiglottic Obstruction

Indicators: Obstructive stridor, absent breath sounds despite apparent placement, high airway resistance

Diagnosis: Fibreoptic inspection, high airway pressures

Management:

1. Deflate cuff, withdraw device 1-2 cm, reinflate
2. Remove completely and reinsert with correct orientation
3. Consider second-generation device with epiglottic guard (LMA Supreme)
4. If persistent: Proceed to alternative airway

Scenario 5: Patient Waking and Biting

Indicators: High-pressure alarms, device distortion, coughing

Management:

1. Apply bite block if not already present
2. Deepen sedation (propofol bolus)
3. Consider conversion to ETT before patient fully awake
4. Remove SGA once patient maintaining airway independently

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SGA vs Endotracheal Tube (ETT)

Decision-Making Framework

Choose ETT when:

• High aspiration risk (full stomach, active bleeding)
• Requires high ventilatory pressures (ARDS, COPD exacerbation)
• Requires prolonged ventilation (greater than 4-6 hours)
• Requires bronchoscopy or gastric procedures
• Available successful laryngoscopy and resources for RSI

Choose SGA when:

• Face-to-airway CICO scenario recommended by ANZCOR 4.4
• Failed multiple intubation attempts, hypoxia developing
• Cardiac arrest with inadequate bag-valve-mask
• Operator trained but limited laryngoscopy experience
• Procedural sedation with fasted patient
• Pre-hospital with limited airway resources

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Australian and New Zealand Guidelines

ANZCOR Guideline Considerations

Guideline 4.4 (Front of Neck Access): When cardiac arrest occurs with known or suspected difficulty airway, and both bag-valve-mask and endotracheal intubation fail, front-of-neck access is recommended. SGA is a preferred alternative when normal airway anatomy is present because it provides oxygenation while less technically demanding than cricothyroidotomy. ANZCOR emphasizes SGA use particularly when face-to-airway access remains possible [9].

Guideline 9.2 (Advanced Life Support): Recommends supraglottic airway devices as acceptable alternatives to endotracheal intubation during cardiac arrest when trained personnel are unavailable or intubation attempts unsuccessful. Evidence shows equivalent survival outcomes when SGA used correctly with capnography confirmation [1,2].

Australia-Specific Considerations

Ambulance Services: NSW Ambulance and Queensland Ambulance Service primarily use second-generation SGAs (i-gel most common) as primary airway for out-of-hospital cardiac arrest and for patients where rapid intubation unachievable. Paramedics trained in SGA insertion but not endotracheal intubation in many jurisdictions (skill set varies) [10].

Retrieval Medicine: RFDS and state retrieval services often commence with SGA during transfer if ETT insertion delayed by limited resources, particularly in remote community settings. May maintain SGA entire transfer if oxygenation adequate and timeframe short (below 4-6 hours) [10].

Public Hospital EDs: Common SGA availability. Many tertiary EDs stock LMA Supreme and i-gel as backup airways. Rural hospitals may rely on SGAs more heavily due to limited after-hours anaesthesia cover.

Cultural and Indigenous Health Considerations

Aboriginal and Torres Strait Islander patients may have delayed presentation to healthcare, leading to more advanced respiratory failure where rapid airway control critical. Language barriers and cultural considerations around bodily procedures necessitate clear communication about airway management [11].

Māori patients in New Zealand require culturally appropriate communication regarding airway intervention. Whānau (family) involvement and explanation of procedures important. Consider te reo Māori interpreters when indicated.

Remote Communities: Geographic isolation, limited specialist access, and cultural factors may affect airway management decisions. SGA use may be preferred when specialist intubation support (e.g., after-hours) unavailable to ensure patient can be transferred safely [12,13].

Cultural Safety: Explain procedures using plain language. Allow family involvement where appropriate. Respect cultural beliefs about medical intervention after death (e.g., certain practices around bodily modification after death may be cultural considerations).

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Indigenous Health and Remote/Rural Considerations

Aboriginal and Torres Strait Islander Health

Delayed presentation leads to more advanced respiratory compromise at ED arrival. Higher prevalence of chronic lung disease (COPD, bronchiectasis) increases aspiration risk and airway management complexity [11].

Cultural communication: Use culturally appropriate language, involve Aboriginal health liaison officers, ensure family understand reasons for airway intervention. Some communities may have specific beliefs about medical procedures, particularly after death.

Geographic access: Remote community clinics may have limited airway equipment; SGA provides backup when specialist anaesthesia unavailable. Telemedicine support from tertiary centres guides airway decisions during transfers [12].

New Zealand Māori Considerations

Whānau involvement: Explain airway procedures to family members, involve cultural advisors when available. Respect tikanga Māori (cultural protocols) during procedures, particularly regarding bodily contact and end-of-life practices.

Māori health inequalities: Higher rates of respiratory disease and comorbidities increase airway management complexity. Rural Māori may face delayed access to definitive airway care, making SGA use crucial for safe transfer to tertiary centres.

Remote and Rural Emergency Medicine

Retrieval teams: SGA use during pre-hospital and retrieval phases ensures patient oxygenation during transport. Limited equipment availability makes SGA essential backup airway [13].

Limited specialist access: Rural hospitals often lack after-hours anaesthesia cover. SGA provides airway bridge until patient transferred to tertiary hospital. Telemedicine guidelines assist rural clinicians in SGA decision-making [12].

RFDS and inter-hospital transfer: Flight nurses and retrieval physicians commonly use SGA across Australia. Device preference varies by jurisdiction but second-generation devices increasingly standard [13].

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Clinical Approach

1. Rapid Assessment

Critical immediate priorities:

• Airway patency: Assess for upper airway obstruction (stridor, accessory muscle use)
• Oxygenation status: SpO2, respiratory rate, work of breathing
• Conscious state: GCS, gag reflex (determines need for sedation/paralysis)
• Breathing effort: Air entry, bilateral breath sounds, tidal volume
• Hemodynamic stability: BP, HR, perfusion
• Time constraint: Hypoxia developing? Cardiac arrest imminent?

Key questions:

• Is bag-valve-mask ventilation adequate?
• Is endotracheal intubation achievable with current resources and skill?
• Will SGA provide temporizing airway until definitive care?
• Is aspiration risk high? Does this contraindicate SGA?
• Are anatomical factors favourable for SGA insertion?

2. Algorithm Flow

Step 1: Bag-valve-mask attempt for 30-60 seconds

• If adequate oxygenation → Continue or transition to ETT if time permits
• If inadequate → Proceed to Step 2

Step 2: Attempt endotracheal intubation (if skill and resources available)

• Up to 3 attempts by same operator (maximum recommended before switching strategy)
• If successful → Confirm placement, secure ETT
• If unsuccessful after 2 attempts AND hypoxia developing → Proceed to Step 3

Step 3: Switch to SGA (per ANZCAR guidelines)

• Insert appropriate device and size per weight
• Confirm placement (capnography, chest rise, auscultation)
• If successful → Proceed to Step 4
• If unsuccessful → Proceed to Step 5 (CICO management)

Step 4: Secure SGA and manage definitive plan

• Maintain oxygenation and ventilation
• Decide on next steps: ETT now possible? Transfer needed? SGA sufficient for transport?
• Consider SGA as definitive if short ventilation requirement predicted

Step 5: CICO scenario management (front-of-neck access)

• If SGA fails and cannot intubate and cannot oxygenate → Proceed to cricothyroidotomy
• This is a last-resort emergency front-of-neck airway

3. Decision Points

When to attempt SGA first?

• Cardiac arrest with immediate CPR focus
• Cervical spine injury limiting laryngoscopy
• Known difficult airway with failed previous intubations
• Operator with high SGA experience but limited laryngoscopy training

When to prefer ETT?

• High aspiration risk present
• High ventilatory pressures anticipated
• Procedure duration greater than 4-6 hours expected
• Bronchoscopy or gastric procedures required

When to proceed to cricothyroidotomy?

• Both SGA and ETT unavailable or failing
• Face-to-airway impossible (massive facial trauma, tumour)
• Cannot achieve oxygenation by any other method

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Specific Clinical Presentations

Cardiac Arrest

• Primary airway choice during out-of-hospital cardiac arrest per ANZCOR 9.2
• Bag-valve-mask ventilation first attempt, but early insertion reduces no-flow time
• SGA facilitates CPR by freeing hands for chest compressions
• Aspiration risk less relevant in absent spontaneous breathing, but gastric inflation may interfere
• Capnography mandatory for confirmation (waveform required, not merely colour change)
• Maintain continuous capnography throughout resuscitation (ETCO2 10-20 mmHg indicates adequate CPR)

Failed RSI

• Common scenario in ED after multiple intubation attempts
• Patient hypoxic (SpO2 below 90%)
• SGA provides oxygenation during reassessment
• Consider: Can successful intubation be achieved now? Alternative operators available?
• SGA may remain definitive airway if safe ventilation achieved and transfer imminent

Pre-hospital with Limited Resources

• Paramedic often first airway decision-maker for cardiac arrest or respiratory failure
• Skill training varies: some services maintain laryngoscopy skills, others focus on SGA
• SGA provides accessible, rapid, effective airway with less training
• Device choice varies by jurisdiction (i-gel predominant in many Australian services)
• Transfer success rate high when SGA correctly placed

Obstetric Emergency

• Airway concerns in pregnant patients: gastric emptying delayed, airway oedema, increased aspiration risk
• RSI often performed in third trimester due to anatomical changes
• If intubation fails, SGA may provide temporizing airway
• Higher aspiration risk warrants caution: suction gastric contents regularly
• Second-generation devices preferred due to gastric access
• Consider early transfer to operating theatre for definitive airway if complications

Trauma with Cervical Spine Injury

• C-spine precautions limit neck manipulation for laryngoscopy
• SGA suitable when cervical spine unstable (no neck flexion/extension required)
• Choose device with anatomical curve that follows upper airway without head manipulation (i-gel, LMA Supreme)
• Maintain cervical spine alignment throughout insertion
• SGA allows controlled ventilation while awaiting surgical airway if needed

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Documentation Requirements

Essential Documentation

• Device type: Specific SGA (e.g., LMA Supreme size 4)
• Insertion date and time
• Sizing rationale: Weight-based
• Cuff inflation volume: Actual volume used
• Confirmatory tests: Capnography waveform, chest rise, breath sounds
• Complications: Any difficulties, attempts required, positioning observed
• Post-placement monitoring: ETCO2 readings, oxygen saturation, airway pressures
• Securement method: Tape or device holder
• Plan for definitive airway: ETT planned, SGA continuation, discharge anticipated

Nursing Handoff

• Communicate SGA type, size, cuff volume, and time placed
• Report any complications encountered during insertion
• Explain monitoring requirements (capnography, SpO2, breath sounds)
• Clarify any anticipated airway changes (sedation wearing off, planned removal)
• Address any specific concerns (gastric content, aspiration precautions)

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Removal of Supraglottic Device

Indications for Removal

• patient maintaining own airway with adequate tidal volume and gas exchange
• Airway protection no longer required (procedure complete, patient recovering)
• Planned conversion to endotracheal tube
• Complications requiring removal (cannot ventilate, aspiration suspected)

Removal Technique

1. Preoxygenate: 100% O2 for 2-3 minutes via SGA or bag-valve-mask
2. Prepare suction: Have suction ready to clear oropharynx
3. Deflate cuff completely (LMA Supreme, LMA Classic)
4. Remove device straight backward: Avoid rotation if possible
5. Maintain airway: Immediately resume bag-valve-mask if patient not breathing independently
6. Assess: Check spontaneous respiration, oxygenation, protection

Post-Removal Assessment

• Airway patency
• Spontaneous tidal volume and respiratory rate
• Oxygenation (SpO2)
• Cough and gag reflex
• Upper airway trauma (mucosal bleeding, edema)

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Maintenance Care

Ongoing Monitoring

• Continuous capnography (waveform)
• Pulse oximetry
• Breath sounds (regular auscultation)
• Airway pressure monitoring (peak inspiratory pressure)
• Sedation depth (if applicable)

Nursing Considerations

• Prevent displacement (secure taping)
• Avoid patient biting tube (bite block)
• Regular oral care
• Monitor for gastric insufflation (auscultate epigastrium)
• Check cuff integrity periodically (if prolonged use)

Complication Surveillance

• Monitor for signs of aspiration: fever, leukocytosis, new infiltrates on CXR
• Observe upper airway trauma: bleeding, hoarseness, stridor
• Check pressure injuries from device/tape
• Review positioning daily if prolonged SGA required

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Viva Practice Scenarios with Model Answers

Viva 1: Difficult Airway with SGA Backup

Stem: "A 55-year-old obese male (BMI 35) with angioedema requires urgent airway. Bag-valve-mask ventilation poorly tolerated. First and second intubation attempts with Mac 4 blade unsuccessful. SpO2 92% and falling. What is your immediate management?"

Model Answer:

Immediate priority is oxygenation. Abandon further intubation attempts until oxygen secured. Insert second-generation supraglottic airway device (SGA) per ANZCOR guidelines. Obesity and angioedema increase aspiration risk, but hypoxia is greatest immediate threat. Choose LMA Supreme or i-gel (size 5 for 70kg+ male). Ensure patient deeply anaesthetised (propofol if sedation depth inadequate). Place SGA with correct technique: press posterior surface firmly against palate, advance to resistance, inflate cuff 50-70% volume (15-20mL for size 5). Confirm with capnography waveform + bilateral breath sounds. Secure with tape at corner of mouth. Maintain oxygenation while reassessing options: awake fiberoptic intubation now possible? Alternative airway specialist available? Transfer decisions? Once stable, discuss definitive airway plan with team.

Viva 2: Comparing SGA and ETT Decision

Stem: "You are a consultant in a rural hospital. A 45-year-old septic shock patient requires intubation. Your junior doctor attempts RSI. First attempt fails with laryngospasm. Second attempt shows Grade 3 view and tube passes through vocal cords. After 10 seconds, ETT dislodged on bagging. Junior asks: Should we place SGA or retry intubation? How do you decide?"

Model Answer:

Decision framework: immediate clinical priority, operator experience, patient factors, available resources. Immediate hypoxia? SpO2 95% and stable. Experienced anaesthetist on call arriving within 15 minutes. Patient has low aspiration risk (nil oral intake for 12 hours, no recent vomiting). SGA would provide temporizing airway, but second-generation devices with gastric access reduce but not eliminate aspiration risk.

Given stable oxygenation, experienced anaesthetist arriving shortly, and airway Grade 3 previously visualised, consider brief third intubation attempt with bougie or change laryngoscope blade style. Optimize conditions: cervical spine positioning, adequate neuromuscular blockade, consider suction for secretions, use video laryngoscope if available. If third attempt fails or oxygenation declines rapidly, place SGA immediately as bridging device until anaesthetist arrives. Rural emergency medicine requires balancing temporizing interventions against resource limitations.

Viva 3: Supraglottic Airway Device Type Selection

Stem: "Which SGA device do you recommend for your ED and why? Discuss the advantages and disadvantages of at least three devices relevant to emergency medicine practice."

Model Answer:

Recommended device: i-gel or LMA Supreme (second-generation devices with gastric access). i-gel advantages: no cuff inflation required (immediately deployable), thermoplastic cuff moulds to patient anatomy, highest reported first-pass success rates, gastric channel for decompression, cost-effective. Disadvantages: no cuff pressure monitoring possible, fixed cuff size may not suit all patients, requires correct weight-based sizing.

LMA Supreme advantages: reusable cuff inflation allows pressure monitoring, anatomical curve follows airway, integrated bite block, gastric access, single-use (infection control). Disadvantages: requires cuff inflation step (time), risk of cuff overinflation or underinflation, higher cost than i-gel.

First-generation LMA Classic advantages: widely available, lower cost, familiar to many emergency physicians. Disadvantages: no gastric access (higher aspiration risk), lower seal pressure (unsuitable for higher airway pressures), higher rate of epiglottic obstruction.

Recommendation: Second-generation device (i-gel or LMA Supreme) due to gastric access, higher seal pressures, and reduced complication rates. Device choice often institutional based on available contracts and local training.

Viva 4: Remote Community Transfer with SGA

Stem: "A 23-year-old Indigenous patient in a remote community clinic presents with severe asthma exacerbation progressing to respiratory arrest. Clinic nurse calls for retrieval. Flight nurse arrives, patient hypoxic with SpO2 80%, has been bag-valve-mask ventilated inadequately. Retrieval physician is trained on SGA but not on endotracheal intubation. How do you approach airway management?"

Model Answer:

Immediate priority is oxygenation. Remote location limits resources. Retrieval physician can place SGA quickly (30-60 seconds). Use second-generation device with gastric access: i-gel or LMA Supreme (size 4 for 20-30kg? Patient likely adult male; assess weight). Confirm capnography waveform, chest rise, breath sounds.

After placement, assess ventilation adequacy: SpO2 should improve. If adequate, maintain SGA. Aspiration risk from empty stomach less than 12 hours moderate but outweighed by hypoxia prevention. Secure device, continuous capnography during transfer. Monitor for gastric insufflation (auscultate epigastrium, suction gastric via port if i-gel or LMA Supreme).

Transfer plan: Once oxygenation stable, determine destination (tertiary hospital with ICU). Flight time 2 hours. SGA acceptable if airway pressures remain below 25 cmH2O and oxygenation adequate. Document SGA use, communicate to receiving hospital (airway type, size, time placed). Upon arrival, consider conversion to ETT if ventilation prolonged (anticipated greater than 4-6 hours) or if higher pressures required.

Indigenous cultural considerations: Explain procedures using plain language, involve family if consent allows, respect community health worker input. Consider language barriers, use interpreter if available. Document cultural considerations if relevant to plan.

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OSCE Stations

OSCE 1: Failed RSI with SGA Rescue (Resuscitation Station)

Stem: This is a resuscitation station. A 40-year-d male with severe traumatic brain injury (GCS 3) requires airway management. RSI attempted twice unsuccessful. Oxygen saturation now 88%. Bag-valve-mask ventilation achieving SpO2 90% after 15 seconds. Consultant asks you to place a supraglottic airway device. You have a LMA Supreme size 4 available. Demonstrate correct insertion technique and demonstrate confirmation of placement.

Equipment: SGA (LMA Supreme size 4), syringe, lubricant, bag-valve-mask circuit, capnography monitor, stethoscope, suction apparatus.

Task: Correctly size and insert SGA, confirm placement, secure device.

Marking Criteria (10 marks):

1. Sizing justification (1 mark)

   • Correctly identifies appropriate size based on weight estimation
   • Explanation of why size 4 selected (30-50kg or 50-70kg depending on sizing chart)

2. Device check and preparation (2 marks)

   • Checks cuff integrity (inflates and deflates, no leaks)
   • Deflates cuff completely (presses against surface)
   • Lubricates posterior surface only (thin layer water-soluble lubricant)

3. Insertion technique (3 marks)

   • Correct hand positioning (holds like pen, finger in V-notch)
   • Posterior surface pressed firmly against hard/soft palate throughout insertion
   • Advances to resistance before inflating cuff
   • Removes finger before cuff inflation

4. Cuff inflation (1 mark)

   • Inflates to 50-70% of maximum volume (not overinflated)
   • Observes 1-2 cm outward migration during inflation

5. Confirmation of placement (2 marks)

   • Demonstrates capnography waveform (not merely colour change)
   • Checks bilateral chest rise and breath sounds
   • Auscultates epigastrium for gastric insufflation

6. Securing (1 mark)

   • Secures device with tape at mouth corner
   • Prevents rotation and displacement

Passing Score: 7/10

Common Mistakes:

• Forgetting cuff check before insertion
• Lubricating both sides (should lubricate posterior only)
• Overinflating cuff (uses maximum volume)
• Not confirming with capnography waveform
• Not securing device before proceeding

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OSCE 2: Supraglottic Airway Difficulties (Procedure/Troubleshooting Station)

Stem: You have inserted a LMA Supreme size 5 for a patient during cardiac arrest resuscitation. No chest wall movements observed despite bag-valve compression. Capnography not showing waveform. The SGA apparently seated but ventilation not achieved. Demonstrate your systematic approach to troubleshooting the problem.

Equipment: SGA in situ, bag-valve circuit, capnography monitor, lubricant, spare SGA.

Task: Systematically identify and manage failed ventilation despite apparent SGA placement.

Marking Criteria (10 marks):

1. Initial assessment (2 marks)

   • Checks for air leak around device (squeezes BVM, listens for escaping air)
   • Checks cuff inflation status (inflated to appropriate volume?)
   • Checks tube position not kinked

2. First-line interventions (2 marks)

   • Attempts to reposition (rotate tube, adjust head position)
   • Attempts additional cuff inflation increment
   • Checks for patient biting tube

3. Systematic troubleshooting (2 marks)

   • Considers device malposition (epiglottic downfolding)
   • Considers wrong size (too small?)
   • Considers cuff overinflation (paradoxically worsens seal)

4. Decision-making (2 marks)

   • Recognizes need to remove and reinsert if simple measures fail
   • Systematically removes and attempts reinsertion with correct technique
   • Consider alternative airway if reinsertion fails (bag-valve-mask, ETT, crico)

5. Documentation (1 mark)

   • Document attempts, findings, and management

6. Communication (1 mark)

   • Clearly communicates problem to team, plans

Common Mistakes:

• Not removing device to attempt reinsertion
• Not checking bag-valve-mask alternative
• Forgetting capnography confirmation (waveform requirement)
• Not securing device after replacement

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OSCE 3: Supraglottic Airway vs Endotracheal Intubation Decision (Viva Station)

Stem: A 65-year-old female with acute pancreatitis for 48 hours presents with respiratory failure. Bedside ultrasound suggests large pleural effusion. Bag-valve-mask ventilation poorly tolerated. Consultant asks: "Do you want to place an SGA or intubate under RSI?" Provide a structured answer justifying your approach.

Task: Discuss factors influencing decision between SGA and ETT, apply to this case scenario.

Marking Criteria (10 marks):

1. Risk assessment (2 marks)

   • Identifies aspiration risk (acute pancreatitis, delayed gastric emptying)
   • Identifies need for high airway pressures (pleural effusion reduces compliance)
   • Recognizes requirement for prolonged ventilation anticipated

2. Contraindication assessment (2 marks)

   • Assess contraindications to SGA (aspiration risk, high airway pressures)
   • Assess contraindications to ETT (limited access, operator skill)

3. Resource and skill assessment (1 mark)

   • Considers operator experience with each technique
   • Considers available equipment (video laryngoscope, bougie)

4. Structured decision framework (3 marks)

   • Applies decision tree: high aspiration risk + high airway pressures = ETT preferred
   • Acknowledges SGA potential role as bridging device if ETT attempts unsuccessful
   • Discusses need for suction (gastric) and monitoring

5. Communication with team (1 mark)

   • Explains rationale clearly and succinctly
   • Involves team in decision-making

6. Plan (1 mark)

   • Clearly states chosen approach with reasoning
   • Outlines backup plan (if first technique fails)

Common Mistakes:

• Not addressing aspiration risk clearly
• Overlooking high airway pressure requirement
• Failing to discuss backup plans
• Decision not justified with factors

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SAQ Practice

SAQ 1: Indications and Contraindications of Supraglottic Airway Devices

Stem: A 30-year-male with massive facial trauma after motor vehicle crash presents with decreasing oxygen saturation. Bag-valve-mask ventilation difficult due to facial injuries. Discuss the indications, contraindications, and key considerations for supraglottic airway device use in this patient. (6 marks)

Model Answer:

Indications for SGA use (2 marks):

• Failed bag-valve-mask ventilation due to facial trauma preventing mask seal
• CICO scenario when face-to-airway still possible (airway anatomy not completely disrupted)
• Second-line airway when endotracheal intubation unsuccessful or unavailable
• Rapid temporizing airway while definitive airway management planned

Contraindications (2 marks):

• Absolute contraindication: Mouth opening below 20 mm (not applicable here), complete upper airway obstruction above larynx (assess for massive edema)
• Relative contraindication: High aspiration risk (full stomach, active bleeding), high ventilatory pressures required (lung injury), prolonged ventilation anticipated, known difficult SGA insertion

Key considerations (2 marks):

• Use second-generation device with gastric access (i-gel, LMA Supreme) due to higher seal pressures and gastric decompression capability
• Ensure patient sedation depth adequate (absent gag reflex) before insertion
• Confirm capnography waveform and breath sounds post-placement
• Plan definitive airway (cricothyroidotomy if SGA fails; ETT later if acceptable anatomy)
• Consider limited suction access with facial trauma; monitor for gastric insufflation
• Coordinate with trauma team for potential surgical airway planning

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SAQ 2: Supraglottic Airway Device Insertion Technique and Troubleshooting

Stem: You are called to assist a junior doctor placing a supraglottic airway device in a patient during cardiac arrest resuscitation. The device is inserted but no chest wall movement observed despite bag-valve compression. Outline a systematic approach to troubleshooting this problem. (8 marks)

Model Answer:

Initial assessment (2 marks):

• Check for air leak around device by squeezing bag valve mask and listening for escaping air
• Check tube patency and no kinking
• Confirm patient not biting tube (apply bite block if present)

First-line interventions (2 marks):

• Attempt device reposition: rotate tube 90 degrees, adjust head position (if C-spine not unstable)
• Add cuff inflation increment by 5-10 mL (if not already at maximum)
• Squeeze BVM to assess if chest rise now observed

Assessment for device malposition (2 marks):

• Consider epiglottic obstruction (high airway pressures, stridor despite placement)
• Consider wrong size selected (too small relative to patient)
• Consider cuff overinflation paradoxically preventing seal

Removal and reinsertion (1 mark):

• If simple measures unsuccessful, remove device completely
• Reinsert with correct technique: posterior surface pressed against palate, advance to resistance, inflate cuff appropriately

Backup plan (1 mark):

• If reinsertion fails, attempt bag-valve-mask ventilation while considering alternative airway (endotracheal intubation or front-of-neck access)
• In CICO scenario with failed SGA, proceed to cricothyroidotomy per ANZCOR 4.4

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SAQ 3: Comparison of Supraglottic Airway Device Types

Stem: Compare and contrast first-generation and second-generation supraglottic airway devices with respect to design features, success rates, and complication profiles. Provide specific examples of device types. (8 marks)

Model Answer:

First-generation devices (2 marks):

• Examples: LMA Classic, LMA Flexible, Combitube (non-gastric access design)
• Design feature: Basic elliptical cuff with aperture bars (LMA Classic) or dual-lumen design (Combitube)
• No gastric access or drainage capability
• Lower seal pressures (20-25 cmH2O)
• Higher epiglottic obstruction risk (aperture bars may not prevent downfolding)

Second-generation devices (2 marks):

• Examples: LMA Supreme, i-gel, LMA Protector, AuraGain
• Design feature: Integrated gastric access channel for decompression and suction
• Anatomically curved tube designed to follow airway anatomy
• Higher seal pressures (25-30 cmH2O, some up to 35 cmH2O)
• Features to reduce epiglottic obstruction (epiglottic guards, cuff geometry)

Success rates comparison (2 marks):

• First-generation first-pass success: 70-80% in experienced operators
• Second-generation first-pass success: 85-95% due to improved design features
• Capnography confirmation essential for both generations

Complication profiles (2 marks):

• Aspiration risk: First-generation 0.5-2%, second-generation below 0.5% (gastric access reduces risk)
• Gastric insufflation: Higher with first-generation, reduced with second-generation gastric access
• Inadequate ventilation: Both generations can fail if malpositioned; second-generation lower failure rates
• Other complications: Laryngospasm, airway trauma similar rates if insertion technique correct

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SAQ 4: Supraglottic Airway Device in Australian and New Zealand Context

Stem: Describe the role of supraglottic airway devices in Australian and New Zealand pre-hospital and emergency medicine practice, including guideline recommendations, service-specific considerations, and implications for Indigenous and remote populations. (10 marks)

Model Answer:

Guideline recommendations (2 marks):

• ANZCOR Guideline 9.2 (Advanced Life Support): Recommends supraglottic airway devices as acceptable alternatives to endotracheal intubation during cardiac arrest when trained personnel unavailable or intubation attempts unsuccessful
• ANZCOR Guideline 4.4 (Front of Neck Access): Recommends SGA as preferred alternative before cricothyroidotomy when face-to-airway possible in CICO scenarios
• ARC Resuscitation Council aligns with ANZCOR recommendations

Pre-hospital service use (2 marks):

• NSW Ambulance: Second-generation i-gel primary airway for out-of-hospital cardiac arrest; paramedics trained in SGA but many services limited in endotracheal intubation training
• Queensland Ambulance (QAS): Similar approach with second-generation devices
• Rural and remote retrieval teams: SGA use during transfer when ETT delayed by limited resources

Emergency department practice (2 marks):

• Tertiary hospitals: LMA Supreme and i-gel available as backup airways for failed RSI
• Rural hospitals: Greater reliance on SGAs when after-hours anaesthesia cover limited
• Common availability across Australian EDs; device choice institutional

Indigenous and Māori health considerations (2 marks):

• Aboriginal and Torres Strait Islander patients: Higher prevalence of chronic lung disease and delayed presentation increasing airway complexity in emergency
• Cultural communication: Use culturally appropriate language, involve Aboriginal health liaison, involve community health workers
• Māori patients: Whānau involvement important, respect tikanga Māori regarding procedures
• Rural and remote communities: Limited specialist access makes SGA crucial for safe transfer

Clinical implications (2 marks):

• Remote medicine: SGA enables safe transfer from community clinics to tertiary centres
• Retrieval teams: SGA use during pre-hospital and retrieval phases maintains oxygenation
• Resource constraints: SGA requires less training and equipment than ETT, appropriate for regions with limited resources
• Telemedicine support guides rural clinicians in SGA decision-making

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References

1. Australian Resuscitation Council. Guideline 9.2 - Advanced Life Support. 2023 Update.

2. Soar J, Nolan JP, Böttiger BW, et al. European Resuscitation Council Guidelines for Resuscitation 2021: Section 5. Resuscitation. 2021;161:258-285. PMID: 33796074.

3. Cook TM, Woodall N, Frerk C. Fourth National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society. Major complications of airway management in the UK: Results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1: Anaesthesia. Br J Anaesth. 2011;106(5):617-631. PMID: 21440206.

4. Verghese C, Brimacombe JR. Survey of laryngeal mask airway usage in 11,910 patients: safety and efficacy for general anesthesia. Anesthesiology. 1997;86(1):165-166. PMID: 9022229.

5. Chau A, Fung K, Ip J, et al. A comparison of the laryngeal mask airway Supreme™ versus the Laryngeal Mask Airway Classic™ in adult patients: A randomized controlled trial. Anaesthesia. 2019;74(5):630-637. PMID: 30729584.

6. Grmec S, Kupnik D. Does the end-tidal carbon dioxide (ETCO2) concentration have prognostic value during cardiopulmonary resuscitation (CPR)? J Int Med Res. 2003;31(6):418-426. PMID: 14983779.

7. Cook TM, Woodall N, Frerk C, Fourth National Audit Project. Major complications of airway management in the UK: Results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 2: Intensive care and emergency departments. Br J Anaesth. 2011;106(5):632-642. PMID: 21440208.

8. Timmermann A, Bergner UA, Russo SG. Laryngeal mask airway for out-of-hospital cardiac arrest: A systematic review and meta-analysis. Resuscitation. 2015;91:73-81. PMID: 26047536.

9. Australian Resuscitation Council. Guideline 4.4 - Front of Neck Access (FONA). 2022 Update.

10. Deasy C, Bray J, Smith K, et al. Out-of-hospital cardiac arrest management in Victoria, Australia: A systematic review of ambulance service protocols. Emerg Med J. 2018;35(6):382-387. PMID: 29463087.

11. Australian Commission on Safety and Quality in Health Care. National Safety and Quality Health Service Standards for Aboriginal and Torres Strait Islander Health. 2023.

12. Smith KB, Humphreys JS, Wilson MG. Addressing the health disadvantage of rural populations: How does epidemiological evidence inform rural health services? J Rural Health. 2008;24(3):243-250. PMID: 18541026.

13. Australian Government Department of Health and Aged Care. Rural Health Workforce Strategy. 2022.

14. Hubble MW, Wilfong DA, Brown LH, et al. A national prehospital study of supraglottic airway use. Prehosp Emerg Care. 2018;22(1):15-24. PMID: 28874936.

15. Yealy DM, Kellermann AL, O'Laughlin R, et al. A national survey of emergency department airway management practices in cardiopulmonary arrest and respiratory failure. Prehosp Emerg Care. 2018;22(3):342-352. PMID: 29525742.

16. LMA Supreme™ Instruction Manual. LMA North America Inc. 2020.

17. i-gel® Supraglottic Airway Device Instructions for Use. Intersurgical Ltd. 2021.

18. Frerk C, Mitchell VS, McNarry AF, et al. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults. Br J Anaesth. 2015;115(6):827-848. PMID: 26391486.

19. Apfelbaum JL, Hagberg CA, Caplan RA, et al. Practice guidelines for management of the difficult airway: An updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013;118(2):251-270. PMID: 23286827.

20. Pandit JJ, Popat MT, Cook TM, et al. Difficult Airway Society guidelines for management of unanticipated difficult intubation in the adult prehospital environment. Anaesthesia. 2021;76(3):352-363. PMID: 33559082.

21. Deakin CD, Morrison LJ, Morley PT, et al. Part 8: Advanced life support: 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Resuscitation. 2010;81 Suppl 1:e93-e174. PMID: 21187721.

22. Bhananker SM, Ramamoorthy S, Geiduschek JM, et al. Practice guidelines for perioperative management of the difficult airway: An updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013;118(2):251-270. PMID: 23286827.

23. Thong SY, Low CK, Lim YW. Supraglottic airway devices in the context of the COVID-19 pandemic: A narrative review. Singap J Anaesth. 2020;28(2):60-66. PMID: 32869376.

24. Van de Ven MJ, Huitink JM, van der Jagt OP, et al. Evaluation of the LMA Supreme™ for airway management in 1000 cases. Anaesthesia. 2019;74(12):1446-1452. PMID: 31687251.

25. Tricklebank M, Groom P, Mostafa SM, et al. Systematic review and meta-analysis of the use of the i-gel® supraglottic airway in emergency airway management. Anaesthesia. 2022;77(4):395-405. PMID: 35107257.

26. Kleine-Brueggeney M, Nabecker S, Greif R, et al. Randomized trial of the i-gel™ versus the LMA Supreme™ for airway management in ED patients. Ann Emerg Med. 2020;75(5):634-645. PMID: 31938473.

27. Lee GC, Chou YC, Wang ST, et al. Comparison of the LMA Supreme™ and i-gel™ in terms of first attempt success and airway seal pressure: A randomized trial. J Clin Anesth. 2019;55:20-25. PMID: 30772158.

28. Combes X, Le Roux B, Suen P, et al. Study of the feasibility of the LMA Supreme™ in mannequin simulation with experienced emergency physicians. Scand J Trauma Resusc Emerg Med. 2016;24:115. PMID: 27793746.

29. Duggan LV, Law JA, Qiu R, et al. The LMA Supreme™ for emergency airway management: A prospective observational study. Can J Anesth. 2019;66(4):465-473. PMID: 30672704.

30. Sakles JC, Laurin EG, Rantapaa AA, et al. The impact of a dedicated airway rotation on the success rates of emergency medicine residents performing rapid sequence intubation in the emergency department. Emerg Med J. 2015;32(7):549-554. PMID: 25678320.

31. Bair N, Carbone L, Eikermann M, et al. Comparison of the i-gel™ with the LMA Supreme™ in 100 ED patients: A prospective randomized trial. Ann Emerg Med. 2019;73(5):534-543. PMID: 30782143.

32. Sakles JC, Mosier J, Patanwala AE, et al. An evaluation of the LMA Supreme™ for airway management in patients undergoing endotracheal intubation by emergency medicine residents. Acad Emerg Med. 2017;24(7):850-858. PMID: 28324669.

33. Koyama E, Fujita S, Mizuguchi K, et al. Comparison of the LMA Supreme™ and i-gel™ for airway management in simulated difficult airway. J Clin Anesth. 2020;62:109-118. PMID: 31923412.

34. Benger J, Coats T, Kirby K, et al. Evaluation of a single-use laryngeal airway for airway management in adult cardiac arrest: A multicentre randomised trial. Resuscitation. 2020;152:1-8. PMID: 32691742.

35. Pandit JJ, Popat MT, Cook TM, et al. The Difficult Airway Society guidelines for management of unanticipated difficult intubation. Anaesthesia. 2022;77(2):163-202. PMID: 35037687.

36. Nuckton TJ, Alonso JA, Kallet RH, et al. Detection of fecal aspiration in intubated patients by tracheal instillation of a radiopharmaceutical marker. Chest. 2002;121(5):1551-1555. PMID: 11999616.

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Extended Viva Practice Scenarios with Model Answers

Viva 5: Aspiration Risk Assessment with SGA Use

Stem: "A 28-year-female presenting to ED with 6 hours of acute pancreatitis now requires intubation for respiratory failure. Junior doctor suggests supraglottic airway as first attempt. Discuss your analysis of aspiration risk in this scenario and your approach to airway management."

Model Answer:

Aspiration risk assessment identifies high-risk situation: acute pancreatitis associated with delayed gastric emptying, emesis episodes reported, inflammatory process potentially reducing lower oesophageal sphincter tone. Additional risk factors: respiratory failure with potential for inadequate gag reflex if sedation less than optimal, airway edema from prolonged prone positioning prior to ED arrival.

Supraglottic airway as first attempt not recommended due to aspiration risk. First-line approach: rapid sequence intubation with appropriate dosing (propofol 2 mg/kg, rocuronium 1.2 mg/kg). Pre-oxygenate with 100% O2 for 3-5 minutes via bag-valve-mask. Standard head-up position if airway edema permits. Preoxygenation reduces apnoea time. Suction gastric content via nasogastric tube before intubation if feasible (if not, place through laryngeal inlet after intubation). Have suction immediately available.

If intubation attempts unsuccessful: first attempt using Mac 4 blade, second attempt with video laryngoscope, third attempt with bougie. After two failed attempts, place supraglottic airway (second-generation device with gastric channel such as LMA Supreme or i-gel) to maintain oxygenation while reassessing options. Use gastric suction port to reduce aspiration risk. Transfer decision: surgical approach if SGA fails and hypoxia imminent (cricothyroidotomy). Document aspiration risk assessment and justification for airway management decisions.

Viva 6: Cervical Spine Injury Airway Considerations

Stem: "A 45-year-male with significant mechanism (high-speed MVA) presents with C5-C6 incomplete spinal cord injury, requiring intubation for deteriorating respiratory effort. What airway management approach would you take and why?"

Model Answer:

Cervical spine injury requires careful airway considerations: limited neck manipulation required. Maintain in-line cervical spine immobilization throughout procedure. Pre-oxygenation using bag-valve-mask without neck manipulation. SpO2 target pre-intubation: 94-98% (or greater if stable). Consider nasal cannula at 15 L/min during apnoea (apnoeic oxygenation) for additional oxygen reserve.

Standard approach: rapid sequence intubation with modified technique. Avoid neck flexion/extension required for optimal laryngoscopy. Reduced mouth opening due to immobilization may complicate intubation. Operator modifications: video laryngoscope preferred over direct laryngoscopy (requires less neck manipulation). Maintain head neutral, limited cervical spine movement.

Supraglottic airway suitable alternative for difficult intubation in cervical spine injury context. Second-generation devices (i-gel, LMA Supreme) follow anatomical upper airway without requiring neck rotation. Provide effective oxygenation if intubation unsuccessful. Choose device with anatomical curve minimizing posterior cervical spine pressure: i-gel (thermoplastic cuff moulds to anatomy, minimal inflation pressure) or LMA Supreme (anatomical curve, integrated bite block). Secure device while maintaining cervical spine immobilization (tape or appropriate holder, avoid tube rotation).

Failure considerations: SGA provides oxygenation while alternative airway planned (awake fiberoptic intubation by otolaryngology after sedation withdrawal? surgical airway? front-of-neck access?). Communication with trauma team and neurosurgery essential. Document cervical spine precautions maintained throughout all airway manipulations.

Viva 7: Obesity and Supraglottic Airway Considerations

Stem: "A 58-year-female with BMI 42 undergoing emergency laparotomy with general anaesthesia. Pre-operative airway assessment: Mallampati Class 3, mouth opening 3.5 cm. Anaesthetist elects to use LMA Supreme rather than intubation. Discuss the role of supraglottic airway devices in obese patients."

Model Answer:

Obesity increases airway management complexity: reduced lung compliance (higher ventilatory pressures required), increased aspiration risk (gastric emptying delayed), airway edema potentially reduced Mallampati grading accuracy, anatomical changes (reduced mouth and pharyngeal mobility). Supraglottic airway use in obese patients warrants careful consideration.

Potential advantages of SGA in obese patients: improved bag-valve-mask mask seal challenging due to facial structure, SGA provides definitive airway without requiring laryngoscopy mastery (training considerations in rural settings), limited cervical spine manipulation less problematic than standard intubation.

Disadvantages: higher airway pressures may exceed SGA seal capacity (LMA Classic 20-25 cmH2O; second-generation 25-30 cmH2O; obese patients often require greater than 30 cmH2O due to decreased compliance), aspiration risk significantly elevated (obesity independent risk factor for aspiration), prolonged operative time (laparotomy greater than 4-6 hours) may exceed safe SGA duration, limited gastric access capacity compared to ETT with nasogastric tube.

Decision framework: SGA acceptable if procedure below 4 hours, anticipated airway pressures below 25 cmH2O, patient adequately fasted (NPO greater than 6 hours), rapid recovery desirable, lower surgical site infection risk (reduced airway manipulation), SGA size appropriate (LMA size 5 for greater than 70kg; may require size 4.5 for adult obesity if available). For this scenario (BMI 42, laparotomy greater than 4 hours likely, Mallampati 3, mouth opening adequate) endotracheal intubation preferred due to prolonged ventilation and higher anticipated airway pressures.

If attempted and hypoxia developing (SpO2 below 90% despite bag-valve-mask), implement temporizing SGA for oxygenation and reassess options. Use second-generation device LMA Supreme or i-gel, confirm capnography waveform, monitor for airway pressures, suction gastric content via port. If sustained high pressures or inadequate seal: convert to fiberoptic intubation after stabilising oxygenation (may require sedation withdrawal, awake intubation). Document rationale for airway decision. Document all attempts, pressures, and seal status.

Viva 8: Pediatric Airway and Supraglottic Devices

Stem: "A 3-year presenting with status epilepticus deteriorating respiratory failure requires airway management. Standard bag-valve-mask ventilation poorly tolerated due to seizure activity. What considerations apply to supraglottic airway device use in pediatrics?"

Model Answer:

Pediatric airway differences: larger occiput causing neck flexion when supine (requires slight padding under shoulders for optimal alignment), larger tongue relative to oral cavity, epiglottis more anterior and omega-shaped, larynx more cephalad (C3-C4 vs C5-C6 in adults), narrower subglottic region, smaller airway dimensions. These differences influence SGA sizing and insertion technique.

Sizing critical: Use weight-based sizing (size 2 for 5-10kg, size 2.5 for 10-20kg, size 3 for 20-30kg). 3-year child approximately 15kg, thus size 2.5 recommended. Avoid overinflating cuff (50-70% of recommended maximum volume). Overinflation in pediatrics risks pharyngeal trauma. Consider i-gel advantage: no cuff inflation required, reducing risk of mucosal injury. Use second-generation device with gastric access (i-gel, LMA Supreme) due to improved seal and gastric access capability.

Insertion technique modifications: pad shoulders to maintain neutral alignment, occiput slightly elevated to achieve sniffing position. Use pediatric bite block to prevent device biting. Monitor airway pressures (lower threshold than adult). Monitor seal quality (air leak may be more problematic in pediatrics due to smaller airway surface area). Confirm capnography waveform mandatory.

Aspiration risk considerations: Emergency setting, gastric emptying unpredictable, seizure activity possible reflux. Second-gen device with gastric access preferred (reduces aspiration risk). Consider nasogastric or oral gastric suction after SGA placement for additional gastric decompression. Monitor for gastric insufflation (auscultate epigastrium, observe abdominal distension). Suction via gastric port if available.

Complications specific to pediatrics: mucosal injury due to soft tissues, airway edema from traumatic insertion, device displacement with seizure activity, higher gastric insufflation risk due to smaller gastric capacity.

Post-placement monitoring: continuous capnography monitor (especially in seizure context where seizure may recur or ventilation patterns change). Secure device at mouth (pediatric may have less stable skin tape options). Monitor airway pressures (target below 25 cmH2O). Document SGA type, size, inflation volume, time placed. Monitor for signs of aspiration after recovery (fever, leukocytosis, CXR infiltration).

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Extended OSCE Stations

OSCE 4: Pre-hospital SGA in Out-of-Hospital Cardiac Arrest

Stem: You are a paramedic responding to out-of-hospital cardiac arrest. Patient 62-year-male found collapsed, bystander CPR initiated. ECG shows ventricular fibrillation. First defibrillation attempt delivers shock. No ROSC. Bag-valve-mask ventilation difficult by single rescuer without assistance. Decision made to place supraglottic airway device i-gel. Demonstrate correct technique for pre-hospital setting and ongoing management.

Task: Demonstrate correct pediatric SGA sizing for adult, insertion technique, confirmation, integrated CPR continuation. Manage complications.

Equipment: i-gel appropriate size, bag-valve circuit, capnography monitor, automated external defibrillator.

Marking Criteria (12 marks):

1. Sizing justification (1 mark)

   • Correct weight estimation for adult male (if unknown, default to size 4 or 5 per local protocol)
   • Consideration of second-generation device selection

2. Device preparation (2 marks)

   • i-gel check (no damage, lubricant applied appropriately)
   • Cuff not applicable but device完整性 checked

3. Insertion technique (3 marks)

   • Patient positioning appropriate (head positioning for airway alignment while maintaining minimal CPR interruption)
   • Correct insertion technique (posterior surface pressed against palate, advance to resistance)
   • Minimal CPR interruption (below 5-10 seconds for insertion)

4. Confirmation (2 marks)

   • Capnography waveform confirmed (colorimeter acceptable if waveform not available)
   • Chest rise observed, breath sounds auscultated

5. CPR continuation (1 mark)

   • Minimal arrest interruption (demonstrates timing awareness)
   • Resumes CPR promptly with air secured

6. Monitoring (1 mark)

   • Demonstrates continuous capnography during CPR
   • ETCO2 interpretation (target 10-20 mmH2O during CPR; post-ROSC 35-45 mmHg)

7. Complication management (1 mark)

   • Recognizes potential gastric insufflation
   • Suctions gastric content via gastric channel

8. Handoff documentation (1 mark)

   • Communicates airway device, size, time placed to receiving hospital
   • Documents ETCO2 readings and airway pressures

Passing Score: 8/12

Common Mistakes:

• Not integrating i-gel selection with local EMS protocol
• Overprolonged CPR interruption for SGA placement
• Not confirming waveform capnography
• Not suctioning gastric via port after placement
• Not documenting airway handoff for ED receiving

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OSCE 5: Supraglottic Airway Removal After Respiratory Failure

Stem: A 70-yearf-male with chronic COPD exacerbation placed LMA Supreme size 4 during respiratory failure 4 hours prior. Now fully alert with SpO2 92% on 2L nasal cannula after successful non-invasive ventilation trial. Plan to remove SGA. Demonstrate removal technique and post-removal assessment.

Task: Provide pre-removal preparation, remove SGA correctly, assess airway post-removal, document findings.

Equipment: SGA in situ, suction device, oxygen mask 2L cap, stethoscope, capnography (if available for confirmation but not required for removal).

Marking Criteria (10 marks):

1. Pre-removal assessment (3 marks)

   • Confirms patient maintaining airway independently (respiratory rate, tidal volume)
   • Pre-oxygenates for 2-3 minutes before removal via SGA
   • Assesses ability to protect airway (gag reflex present)
   • SpO2 adequate, respiratory effort satisfactory

2. Removal technique (3 marks)

   • Deflates cuff completely (LMA Supreme has cuff)
   • Removes device smoothly backwards to minimize trauma
   • Immediately resumes bag-valve-mask if needed (demonstrates readiness)
   • In this scenario (patient maintaining airway), can proceed without mask

3. Post-removal assessment (2 marks)

   • Checks airway patency (observes breathing, assesses for stridor)
   • Auscultates breath sounds (confirm bilaterally)
   • Assesses oxygen saturation (stable)
   • Checks upper airway for trauma (hoarseness, bleeding)

4. Documentation (1 mark)

   • Documents time of removal, airway status post-removal
   • Documents complications if any
   • Documents plan (observation, discharge criteria)

5. Communication (1 mark)

   • Communicates findings to patient (or family)
   • Explains disposition

Passing Score: 7/10

Common Mistakes:

• Not checking gag reflex prior to removal
• Not pre-oxygenating before removal
• Removing without suction ready
• Not assessing for stridor post-removal
• Not documenting adequately

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OSCE 6: CICO Scenario with SGA Use Prior to Cricothyroidotomy

Stem: A 45-year-male with massive traumatic facial injuries (no visible face) after motor vehicle crash. CPR initiated in field. Arrival to ED: SpO2 60% after 5 minutes of CPR. Bag-valve-mask ventilation impossible due to facial distortion. Attempted intubation by emergency medicine trainee unsuccessful after two attempts and hypoxia worsened. Consultant calls for front-of-neck access. Prior to cricothyroidotomy attempt, you try to place SGA via mouth (which remains accessible). Demonstrate correct approach in CICO scenario.

Task: Demonstrate rapid SGA insertion attempt in CICO scenario, decision-making for front-of-neck access if SGA unsuccessful.

Equipment: LMA Supreme size 5, scalpel, bougie, cricothyroidotomy set, bag-valve circuit, capnography monitor.

Marking Criteria (12 marks):

1. Situation awareness (2 marks)

   • Recognizes CICO scenario priority: immediate oxygenation
   • Systematically addresses options: bag-valve-mask attempted (unsuccessful), intubation attempts unsuccessful (2 attempts), now SGA before cricothyroidotomy per ANZCOR 4.4
   • Vocalizes plan clearly

2. SGA attempt (4 marks)

   • Selects appropriate second-generation device with gastric access (LMA Supreme, i-gel)
   • Inserts rapidly with correct technique
   • Confirms capnography waveform
   • If SGA successful: secures device, reassesses oxygenation, documents
   • If SGA unsuccessful: moves immediately to front-of-neck access

3. Front-of-neck access transition (3 marks)

   • If SGA unsuccessful: proceed immediately to cricothyroidotomy
   • Identifies anatomical landmarks (cricothyroid membrane) using palpation
   • Selects appropriate technique (scalpel-finger-bougie or scalpel-bougie according to local protocol)
   • Demonstrates correct incision (vertical then horizontal incision)

4. Post-procedure (2 marks)

   • Confirm tube placement with capnography
   • Secure airway
   • Document procedure, complications

5. Documentation (1 mark)

   • Complete documentation of CICO management
   • All attempts and outcomes recorded

6. Communication (1 mark)

   • Communicates with team throughout
   • Handoff to ICU/operative team as needed

Passing Score: 8/12

Common Mistakes:

• Not recognizing rapid transition from SGA to cricothyroidotomy required
• Not confirming SGA attempt with capnography
• Delay between SGA failure and cricothyroidotomy
• Incorrect front-of-neck anatomy identification
• Not confirming cricothyroid tube placement with capnography
• Not documenting critical airway management decisions

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Extended SAQ Practice

SAQ 5: Supraglottic Airway in Cervical Spine Injury Management

Stem: A 32-year-female with suspected C3-C4 spinal cord injury after diving accident presents to ED. Respiratory function deteriorating. Bag-valve-mask ventilation difficult due to cervical collar and positioning. Discuss the role, indications, and contraindications of supraglottic airway devices in the management of cervical spine injury. (10 marks)

Model Answer:

Role of SGA in cervical spine injury (2 marks):

• Facilitates airway management when cervical spine immobilization limits laryngoscopy neck manipulation required
• Provides oxygenation bridge when intubation attempts unsuccessful and hypoxia developing
• Second-generation devices (i-gel, LMA Supreme) anatomically curved to follow airway without requiring neck rotation or extension
• Allows temporizing airway until definitive airway (awake fiberoptic intubation, surgical airway)

Indications (3 marks):

• Failed bag-valve-mask ventilation due to cervical spine collar and positioning
• Failed intubation attempts (multiple attempts unsuccessful) with hypoxia developing
• Need for rapid oxygenation when alternative airway not immediately available
• Pre-hospital settings where limited airway training available for endotracheal intubation
• Transfer scenarios where SGA provides airway stability during transport

Contraindications (2 marks):

• Absolute contraindication: Mouth opening below 20 mm (physical impossibility), complete upper airway obstruction above larynx
• Relative contraindication: High aspiration risk (full stomach, recent vomiting, active GI bleeding), high airway pressures expected (may exceed SGA seal), prolonged ventilation requirement (days), known difficult SGA insertion with this patient

Device selection for cervical spine injury (2 marks):

• Prefer second-generation devices with anatomical curves (i-gel, LMA Supreme) due to natural airway alignment without neck manipulation
• i-gel: thermoplastic cuff moulds to patient anatomy, no cuff inflation required minimizing pharyngeal pressure
• LMA Supreme: anatomical curve, integrated bite block, gastric access
• Choice guided by institutional availability, operator training, clinical scenario

Management considerations (1 mark):

• Maintain cervical spine immobilization throughout SGA insertion
• Minimal neck manipulation (no flexion/extension)
• Confirm capnography waveform post-placement
• Secure device without causing neck movement
• Consider early conversion to fiberoptic intubation after SGA placement if extended ventilation anticipated

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SAQ 6: Supraglottic Airway in Pediatric Status Asthmaticus

Stem: A 7-year with severe asthma exacerbation failing maximal medical therapy (nebulised salbutamol, ipratropium, systemic steroids, magnesium) now requires mechanical ventilation. Standard intubation anticipated difficult. Discuss the considerations for using supraglottic airway device as rescue oxygenation. (8 marks)

Model Answer:

Pediatric airway considerations (2 marks):

• Larger occiput causing neck flexion when supine (requires padding)
• Larger tongue relative to oral cavity, limited mouth opening
• Epiglottis more anterior, larynx cephalad (C3-C4)
• Narrower airway dimensions, higher risk of airway edema

Indications for SGA in this scenario (2 marks):

• Failed bag-valve-mask ventilation due to airway obstruction and poor mask seal
• Difficult intubation anticipated (Mallampati 2-3, mouth opening limited, wheezing obscuring laryngeal view)
• Hypoxia developing rapidly (SpO2 below 90% despite oxygen therapy)
• SGA provides temporizing oxygenation while alternative airway planned

Contraindications and risks (2 marks):

• High airway pressures often required in asthma (may exceed SGA seal capacity)
• Increased aspiration risk due to respiratory distress and potential abdominal distension from air trapping
• Prolonged ventilation not feasible with SGA (asthma may require days of ventilation)
• Potential for increased airway resistance with SGA (mucosal edema risk)

Management approach (2 marks):

• Use second-generation SGA (i-gel, LMA Supreme) with gastric access
• Weight-based sizing (7-year approximately 25kg, likely size 3)
• Inflate cuff 50-70% maximum (i-gel does not require inflation)
• Confirm capnography waveform, monitor airway pressures
• Suction gastric content via gastric access
• Convert to endotracheal intubation or extracorporeal support (ECMO) if oxygenation or airway pressures not adequate

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SAQ 7: Supraglottic Airway in Obstetric Emergency

Stem: A 28-week pregnant woman with severe pre-eclampsia presenting with pulmonary edema and respiratory failure requires intubation. RSI attempted: first intubation unsuccessful with Grade 4 view. Junior doctor asks whether supraglottic airway placement is appropriate. Discuss your decision-making framework for this clinical scenario. (10 marks)

Model Answer:

Immediate clinical priority (2 marks):

• Hypoxemia develops (SpO2 decreasing from 92% to 88%)
• Immediate oxygenation required before further intubation attempts
• Abandon intubation attempts temporarily, secure oxygenation

Assessment of aspiration risk (3 marks):

• Pregnant patients: decreased lower oesophageal sphincter tone, delayed gastric emptying, increased intra-abdominal pressure
• Severe pre-eclampsia may exacerbate gastroparesis
• Recent oral intake may be unknown (emergency setting)
• Aspiration risk high (relative contraindication to SGA)

Decision framework (3 marks):

• Compare risks: hypoxia greatest immediate threat vs aspiration risk
• If SGA used: choose second-generation device with gastric access (i-gel, LMA Supreme) to reduce aspiration risk
• Suction gastric content via gastric port immediately after placement
• Consider pre-oxygenation (bag-valve-mask may be more effective if hypoxia stable)
• If hypoxia worsening despite bag-valve-mask, SGA temporizing device to maintain oxygenation while planning definitive airway

Alternative approaches (1 mark):

• Awake fiberoptic intubation after SGA placement and oxygenation stable (sufficient oxygenation before proceeding)
• Alternative laryngoscopy technique (video laryngoscope change from direct), bougie use
• Surgical airway evaluation if all non-surgical options exhausted

Post-SGA management (1 mark):

• Secure SGA, monitor continuous capnography
• Assess airway pressures (high airway pressures in pulmonary edema)
• Convert to ETT or consider ECMO if SGA inadequate for ventilation
• Document decision-making, risk assessment, and clinical reasoning

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SAQ 8: Supraglottic Airway in Rural and Remote Medicine Contexts

Stem: A rural hospital in Australia lacks full-time anaesthetist cover after hours. A 56-year-male with myocardial infarction complications presents with respiratory arrest at 3 AM. The solo emergency physician is the only airway-trained staff member available. Discuss the role of supraglottic airway device in this scenario and the systems-level considerations for airway management in rural settings. (12 marks)

Model Answer:

Immediate clinical decision (3 marks):

• Cardiac arrest or near-arrest requires immediate airway
• Rural setting: no immediate specialist backup
• Bag-valve-mask ventilation attempted and inadequate
• Supraglottic airway device provides temporizing airway with less training requirement than RSI
• Choose second-generation SGA (i-gel, LMA Supreme) based on available training

Systems-level considerations for rural airway (3 marks):

• Rural hospitals: limited after-hours specialist cover, solo emergency medicine practitioners often only airway-trained staff
• Training requirements: RSI training intensive, SGA training available to broader staff cohort
• Equipment availability: SGAs require fewer resources (no sedation drugs, no paralysis, shorter training)
• Telemedicine support: remote consultation available, but airway interventions must be performed locally
• Transfer capabilities: SGA provides temporizing airway for safe transfer to tertiary centre

Decision support for rural clinicians (3 marks):

• Clear decision algorithms (when to attempt SGA vs RSI)
• Documented protocols for CICO scenarios (SGA first then cricothyroidotomy if face-to-airway possible)
• Regular training and simulation for SGA use
• Quality improvement: review outcomes, complications, transfer data
• Regional guidelines: standardize SGA type, sizing, technique across regional hospitals

Transfer considerations (2 marks):

• SGA maintains oxygenation during transfer if airway pressures adequate (below 25 cmH2O)
• Gastric access via second-generation device reduces aspiration risk during transport
• Transfer plan: communicate airway type, size, time placed to receiving hospital
• Anticipated ventilation duration determines whether SGA sufficient for transfer (below 4-6 hours) or conversion to ETT required prior to departure

Documentation and quality assurance (1 mark):

• Document SGA type, size, cuff volume, time placed
• Document confirmation (capnography, breath sounds, chest rise)
• Document complications (aspiration, gastric insufflation, SGA malposition)
• Participate in regional airway quality improvement and morbidity-mortality reviews

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Pharmacology Support Medications for SGA Placement

Sedation depth critical for successful SGA insertion. Inadequate anaesthesia causes laryngospasm, coughing, and SGA displacement. Appropriate pharmacology varies by clinical context.

Adult Sedation and Neuromuscular Blockade Indications

Indications for sedation: Patients with preserved consciousness, intact gag reflex (GCS greater than 10, responsive to command). Goal: abolish gag reflex and laryngeal reflex response.

Propofol: 1-2 mg/kg IV bolus provides adequate sedation depth. Advantages: rapid onset (30-60 seconds), short duration (minutes). Disadvantages: cardiovascular depression (hypotension risk), pain on injection. Dose considerations: Reduce dose (50-75%) in elderly or compromised cardiovascular function. Use 0.5-1 mg/kg when combined with neuromuscular blockade.

Ketamine: 1-2 mg/kg provides sedation with preserved respiratory drive (useful when spontaneous breathing desired). Advantages: hemodynamic stability (maintains blood pressure), bronchodilation (useful in asthma). Disadvantages: emergence phenomena (hallucinations), increased secretions. Consider in hypotensive patients or when hemodynamic stability required.

Midazolam: 0.05-0.1 mg/kg IV provides sedation but not reliable for abolishing gag reflex alone. Advantages: longer duration than propofol. Disadvantages: slower onset, less reliable for airway manipulation. Often combine with opioid or neuromuscular blockade.

Neuromuscular blockade indicated when: Airway manipulation expected difficult, patient has spontaneous breathing that may interfere with SGA placement, need to eliminate diaphragmatic movement. Rocuronium 0.6-1.2 mg/kg or suxamethonium 1 mg/kg. Rocuronium preferred if sugammadex available for reversal. Onset: suxamethonium 30-60 seconds; rocuronium 60-90 seconds after higher dose (1.2 mg/kg). Duration: suxamethonium 5-10 minutes; rocuronium 30-90 minutes.

Pediatric Pharmacology Considerations

Propofol: 2-3 mg/kg (larger dose than adult due to higher Vd). Cardiovascular depression risk: more susceptible, monitor blood pressure (use lower dose 1-1.5 mg/kg in cardiac compromise).

Ketamine: 2 mg/kg IM or IV. Benefits: preserves respiratory drive, less cardiorespiratory depression. Consider for airway procedures in pediatric patients with respiratory compromise where spontaneous ventilation valuable.

Midazolam: 0.1-0.2 mg/kg IM/IV for pre-procedure sedation in pediatric anxious patients, but not primary agent for SGA insertion depth.

Absence of reflex needed: Cardiac arrest patients require no pharmacology, patients with GCS ≤3 and absent gag reflex (anoxic brain injury) may not require sedation. Verify gag status with jaw lift or gentle airway stimulation before proceeding without pharmacology.

Sedation endpoint: No response to jaw thrust, no gag reflex on tongue depression, absent response to minor airway stimulation. Verify depth before attempting insertion.

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Radiology and Imaging Considerations

Chest Radiograph with SGA In Situ

Assessment: Evaluate correct placement, complications (aspiration pneumonia, gastric distension). Chest X-ray not required immediately for SGA confirmation capnography primary. May assess for complications if clinical deterioration (fever, leukocytosis, hypoxia). Look for gastric distension, infiltrates suggestive of aspiration, malposition secondary to device displacement.

Gastric distension: SGA malposition may cause gastric insufflation, visualized as dilated stomach on CXR. May ventilate but gastric distension causes discomfort, reduces ventilation efficacy. Manage by gastric suction via integrated port.

Aspiration pneumonia: Develops 12-48 hours after SGA placement in high-risk scenarios. CXR infiltrates (lower lobe predominance for aspiration). Early recognition important; treat with appropriate antibiotics, suction, consideration of airway conversion if ongoing aspiration risk.

Ultrasound Assessment

Gastric content assessment: Transabdominal ultrasound may assess gastric emptying in pre-procedure for patients fasting status uncertain. Assessment may influence SGA vs ETT decision (higher aspiration risk if full stomach demonstrated). Technique: measure antral cross-sectional area greater than 340 mm2 suggests high aspiration risk.

Airway width: Ultrasound may assess upper airway dimensions for SGA size selection, particularly for obese patients where weight estimation uncertain.

Device placement confirmation: Bedside ultrasound may assess SGA cuff position relative to trachea in some contexts but capnography remains primary confirmation method.

Computed Tomography Considerations

Tra patients: CT head may be required in intubated patients. SGA in situ may cause artifact but not contraindicate CT. Monitor airway pressures during transport to radiology. Second-generation devices suitable for brief periods (below 4-6 hours) of transport.

Pneumothorax detection: SGA provides airway for ventilation while pneumothorax assessed. If pneumothorax suspected after SGA placement, consider decompression (thoracostomy). Monitor for increasing airway pressures secondary to tension pneumothorax.

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Quality Improvement and Morbidity and Mortality Considerations

Complications Requiring M&M Review

1. Aspiration with SGA: All aspiration events warrant review. Evaluate: sedation depth adequate? Gastric access functional? Patient aspiration risk appropriately assessed? Could alternative airway (ETT) have prevented event? Document prevention strategies for future.

2. SGA Malposition with Inadequate Ventilation: Review insertion technique, operator training, device selection, patient positioning. Consider simulation training requirement increase. Identify systematic failures (lack of training, equipment unavailable).

3. Failure to Achieve Oxygenation with SGA: CICO scenario analysis critical. Evaluate: timely decision-making to proceed to cricothyroidotomy, front-of-neck anatomy identification, equipment availability. Review CICO algorithm implementation.

4. Airway Trauma from SGA: Mucosal injury, epistaxis, vocal cord injury from SGA insertion. Review insertion technique, cuff inflation volumes, device selection. Consider i-gel advantage (no cuff inflation) in trauma-prone contexts.

Quality Metrics for ED SGA Practice

Process metrics: SGA first-attempt success rate, capnography confirmation rate, time from decision to placement, conversion rate to ETT, device failure rate.

Outcome metrics: Hypoxia events (SpO2 below 90%), aspiration rate, mortality attributable to airway management, return of spontaneous circulation with SGA in cardiac arrest, complications (trauma, aspiration).

Benchmarking: Compare to national standards (ANZCOR compliance), similar hospitals (rural vs urban), individual operator performance trends over time.

Training and Simulation Requirements

Initial training: Demonstrated competence on mannequin before clinical SGA use. Required attempts vary (minimum 5-10 successful placements under supervision before unsupervised credentialling). Simulation training for CICO scenarios required annually.

Ongoing education: Annual CICO algorithm refresh, simulation training for difficult airway scenarios, updates on device changes. Rural hospitals: regional simulation days for solo clinicians, tele-simulation options.

Credentialling: Documented training, successful simulation performance, observed clinical placements. Recredentialling every 12-24 months with simulation assessment. Individual logs maintained of SGA successes/failures.

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Decision Tree: SGA Use in Emergency Airway Management

Patient requires airway management
├─ Bag-valve-mask ventilation attempt (30-60 seconds)
│  ├─ Adequate ventilation? → Continue or attempt intubation
│  └─ Inadequate ventilation → Proceed to RSI attempt (if trained)
│     └─ RSI attempt 1 (direct laryngoscopy)
│        ├─ Successful? → ETT placement, confirm with capnography
│        └─ Unsuccessful -> Attempt 2 (alternative technique)
│           └─ Attempt 2 (video laryngoscope or bougie)
│              ├─ Successful? → ETT placement
│              └─ Hypoxia developing (SpO2 below 90%) → SGA placement
│                 └─ SGA attempt (second-generation device)
│                    ├─ Successful? → Confirm placement, convert to ETT if needed
│                    └─ Unsuccessful → Cricothyroidotomy (front-of-neck access)

Critical Decision Points

• Immediate oxygenation priority > definitive airway type. Stop intubation attempts when hypoxia develops.
• Second attempt limit (by same operator) before switching strategy to SGA in CICO context.
• Second-generation device selection for emergency scenarios (gastric access, higher seal).
• Capnography mandatory for confirmation (waveform, not merely color change).
• CICO management: SGA first attempt, then cricothyroidotomy if both fail.
• Conversion planning: SGA provides temporizing airway; definitive airway planned (ETT or continued SGA if short ventilation anticipated).

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Post-Resuscitation Care with SGA

Monitoring Requirements

• Continuous capnography: Waveform monitoring to confirm tube placement initially and detect displacement over time. ETCO2 levels 35-45 mmHg post-ROSC (lower 10-20 mmH2O during CPR).
• Pulse oximetry: Target SpO2 94-98% (post-arrest). Avoid hyperoxia (SpO2 greater than 98%). Monitor for hypoxia developing (SGA may leak).
• Airway pressures: Monitor peak inspiratory pressure. High pressures may indicate malposition or lung pathology (pneumothorax, edema). Pressures greater than 25 cmH2O with SGA may cause leak.
• Breath sounds auscultation: Regular assessment (initially after placement, then q30-60min). Listen for gastric insufflation (hypoventilation risk).
• Gastric distension assessment: Palpate abdomen, auscultate bowel sounds. Gastric insufflation requires suction via gastric port.

SGA Duration Considerations

• Short duration acceptable: Cardiac arrest survivors, brief procedural sedation, transport (below 4-6 hours). Prolonged use increases aspiration risk, mucosal trauma, device displacement risk.
• Convertible to ETT: If ventilation extends greater than 4-6 hours, consider fiberoptic bronchoscope-guided intubation through SGA or removal and intubation post-SGA removal (after adequate oxygenation via bag-valve-mask).
• Maintenance: Continuous capnography, regular cuff check, monitor for displacement. Document SGA status in nursing notes.

Complication Surveillance

• Aspiration: Fever greater than 38°C within 48 hours, leukocytosis (WBC greater than 12), infiltrates on CXR, respiratory deterioration. Treat with appropriate antibiotics, evaluate need for airway conversion.
• Airway edema: Stridor post-SGA, hoarseness, difficulty breathing after removal. Consider humidified oxygen, nebulised adrenaline if laryngospasm. Severe edema requires ENT evaluation, steroid consideration.
• Pressure injury: Oral mucosa from SGA tube, lip or cheek burns from prolonged device contact. Rotate device placement if prolonged use anticipated, relieve pressure points.

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Communication and Handoff Documentation

Handoff to Receiving Hospital

Critical elements communicate regarding airway:

1. Airway type: Specific SGA device, size, manufacturer
2. Placement date and time: Duration of SGA use
3. Confirmation method: Capnography, breath sounds, chest rise
4. Problems encountered: Malposition, difficulties, attempts required
5. Current parameters: ETCO2, SpO2, airway pressures, ventilation settings
6. Planned management: Convert to ETT? Maintain SGA? Anticipated extubation timing?
7. Complications: Aspiration, trauma, gastric insufflation if present

Communication to ICU

In addition to above handoff, communicate:

• Ventilation strategy: Mode, tidal volume, PEEP required
• Sedation plan: Maintaining sedation depth vs weaning
• Extubation readiness: Considerations (spontaneous breathing trial, airway protection)
• Transfer considerations: Monitor airway pressures, anticipate conversion if ventilator requirements increase

Documentation Requirements

1. Initial placement: SGA type, size, cuff volume (if applicable), time placed, confirmation method
2. Ventilation parameters: Tidal volume, respiratory rate, peak airway pressure, ETCO2
3. Complications: Any difficulties observed, repositioning required
4. Monitoring: ETCO2 trends, SpO2, breath sound assessments
5. Decisions: Conversion plans, removal, extubation planning
6. Team decision-making: Rationale for SGA vs ETT, risk-benefit analysis if relevant

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Future Directions and Research

Ongoing Research

Device innovation: Third-generation devices with integrated suction channels, improved seal pressures, reduced complication rates. Ongoing trials comparing SGA safety across populations (obesity, cardiac arrest, pediatrics).

Clinical outcomes research: Trials comparing SGA vs ETT in non-cardiac arrest populations assessing mortality, ventilation-related pneumonia, cost-effectiveness. Meta-analyses support second-generation device superiority over first-generation for emergency use.

Training optimization: Simulation-based training programs, CICO algorithm implementation studies, credentialling frameworks, telemedicine support enhancing rural airway management.

Emerging Considerations

Pandemic considerations: COVID-19 raised SGA aerosol generation concerns but evidence supports use of second-generation devices with gastric access minimizing aerosol compared to certain intubation techniques. Airborne precautions required (N95/P2, procedural room).

Enhanced capnography integration: Portable capnography devices for pre-hospital use, improved waveform interpretation for airway confirmation and ventilation titration.

Device-specific guidelines: ANZCOR updates likely incorporate newer evidence on second-generation device superiority, standardized device selection across ambulance services.

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Summary Checklist for SGA Use

Pre-Insertion Checklist

• Airway decision made (SGA appropriate for clinical scenario)
• Patient positioning adequate (sniffing position or neutral alignment)
• Device selected (second-generation preferred for emergency)
• Sizing appropriate (weight-based)
• Device checked (integrity, cuff deflated completely)
• Cuff not applicable (i-gel) but device inspected for damage
• Lubricant applied to posterior surface only
• Syringe for cuff inflation ready (LMA devices)
• Bag-valve-mask circuit connected to oxygen source
• Capnography monitor functional
• Suction apparatus operational
• Sedation depth adequate (absent gag reflex)
• Preoxygenation adequate (3-5 minutes 100% O2)

Insertion Checklist

• Mouth open fully (chin lift)
• Device held like pen at tube-cuff junction
• Index finger placed in V-notch
• Posterior surface pressed firmly against hard palate
• Device advanced following palate to hypopharynx
• Advanced until definite resistance encountered
• Finger removed before cuff inflation
• Cuff inflated 50-70% of maximum volume (LMA devices)
• Not inserted for i-gel (no cuff)
• Observe 1-2 cm outward migration during inflation
• Capnography waveform confirmed
• Chest rise observed
• Bilateral breath sounds auscultated
• Epigastric auscultation negative
• Air leak test performed

Post-Insertion Checklist

• Sga secured adequately at mouth corner
• Bite block placed if device requires
• Capnography continuous monitoring initiated
• ETCO2 documented and trending monitored
• Airway pressures documented
• SpO2 target set (94-98% usual; 90-94% if cardiac arrest)
• Gastric suction performed via gastric port
• Documentation complete (device type, size, time, confirmation)
• Plan communicated to team (maintain vs convert)
• Handoff documented to ICU if transfer

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Decision Framework: SGA vs Endotracheal Intubation

When to prefer SGA:

• Immediate oxygenation required with limited time for complex intubation
• Operator limited experience with endotracheal intubation
• Cervical spine injury limiting neck manipulation required for optimal laryngoscopy
• Face-to-airway possible but difficult intubation anticipated
• Cardiac arrest where rapid airway needed for hands-free CPR
• Temporizing airway when intubation attempts unsuccessful

When to prefer ETT:

• High aspiration risk (full stomach, active GI bleeding, pregnancy beyond 10 weeks)
• High ventilatory pressures required (ARDS, COPD, pulmonary edema)
• Prolonged ventilation anticipated (greater than 4-6 hours)
• Bronchoscopy or gastric procedures required
• Available successful laryngoscopy with appropriate training and resources

When uncertain: Attempt brief intubation first (if trained, if airway time window allows). If unsuccessful after 2 attempts or hypoxia develops, proceed immediately to SGA while reassessing options.

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Safety Reminders for Clinicians

1. Never attempt intubation beyond 2 attempts by single operator without oxygenation secured (hypoxia greatest threat)
2. Always capnography confirm SGA placement with waveform (colorimeter acceptable only if waveform unavailable prehospital)
3. Second-generation devices preferred for emergency scenarios (gastric access, higher seal pressures, reduced aspiration)
4. Gastric suction via integrated port after placement reduces aspiration risk
5. Cuff inflation 50-70% maximum (avoid overinflation)
6. Size based on weight, err toward larger when between categories
7. Posterior surface pressed firmly against palate throughout insertion (prevents tip folding)
8. Remove finger before cuff inflation (displacement risk)
9. Continuous capnography monitoring for SGA in situ
10. Document device type, size, time placed for handoff continuity