Anaesthesia for Tonsillectomy

Quick Answer

Tonsillectomy presents unique anaesthetic challenges due to the shared airway with the surgeon, risk of post-tonsillectomy haemorrhage (PTH), and frequent paediatric population. Key considerations include:

• Airway Management: Oral RAE (Ring-Adair-Elwyn) endotracheal tube preferred; shared airway requires secure fixation and minimal leak around cuff; tube positioned away from surgical field [1,2]

• Anaesthetic Technique: Balanced anaesthesia with volatile or TIVA; ensure adequate depth before instrument insertion; paracetamol, NSAIDs, dexamethasone for multimodal analgesia [3,4]

• Post-Tonsillectomy Bleeding: Most common serious complication (2-4% primary, 0.1-0.8% secondary); peak at 6-8 hours post-op; requires rapid sequence induction with modified technique (gentle laryngoscopy, smaller tube), volume resuscitation, haemostasis under general anaesthesia [5,6]

• Paediatric Considerations: OSA common; difficult mask ventilation/airway; increased opioid sensitivity; dehydration risk with PTH; perioperative cardiac arrest rare (0.5 per 10,000) [7,8]

• Safety Priorities: Ensure stomach empty in PTH (though emergent); difficult airway cart available; blood products if significant bleeding; awareness of obstructive sleep apnoea syndrome interactions [9,10]

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Indigenous Health Considerations

Aboriginal and Torres Strait Islander Populations

Aboriginal and Torres Strait Islander children experience significantly higher rates of chronic suppurative otitis media (CSOM) and recurrent tonsillitis compared to non-Indigenous Australian children [11,12]. Studies demonstrate Indigenous children have:

• 3-5 times higher incidence of recurrent tonsillitis requiring surgical intervention [13]
• Earlier age of presentation, often <3 years, compared to non-Indigenous peers [14]
• Higher burden of comorbidities, including iron deficiency anaemia and malnutrition, which increase perioperative risk [15]

The higher prevalence of obstructive sleep apnoea (OSA) in Indigenous populations relates to higher rates of chronic rhinitis, adenotonsillar hypertrophy, and socioeconomic determinants including overcrowded housing [16,17]. Remote and rural communities face particular challenges:

• Delayed presentation due to geographic isolation and limited ENT specialist access
• Post-operative follow-up difficulties, increasing risk of missed secondary PTH
• Cultural and language barriers requiring interpreter services or Aboriginal Health Worker involvement
• "Sorry Business" considerations where family structures and cultural obligations may affect surgical scheduling and consent processes

Perioperative considerations for Indigenous children:

1. Enhanced screening for OSA symptoms given higher baseline prevalence
2. Preoperative optimisation of iron deficiency and nutritional status
3. Extended observation post-discharge or telehealth follow-up for remote patients
4. Cultural safety in pain assessment and management, recognising different pain expression norms
5. Family involvement in decision-making, often requiring broader family consultation than typical Western nuclear family models [18,19]

Māori Populations (Aotearoa New Zealand)

Māori children demonstrate similarly elevated rates of ENT surgical intervention:

• Tonsillectomy rates 1.5-2× higher than European New Zealanders [20]
• Higher complication rates, partly attributed to delayed presentation and socioeconomic factors [21]
• Rheumatic fever prevention makes tonsillectomy particularly important given elevated streptococcal carriage rates [22]

Te Tiriti o Waitangi obligations in ENT anaesthesia include:

• Active whānau involvement in perioperative care planning
• Māori Health Workers supporting cultural navigation
• Recognition of whānau, hapū, iwi structures in consent and discharge planning
• Manaakitanga (hospitality/care) principles in family accommodation for those travelling from rural areas
• Addressing rheumatic fever risk through expedited surgery when indicated [23]

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Epidemiology and Clinical Overview

Indications for Tonsillectomy

Absolute indications:

• Peritonsillar abscess (quinsy) - recurrent
• Tonsillar malignancy suspicion
• Obstructive sleep apnoea syndrome (severe)
• Haemorrhagic tonsillitis

Relative indications:

• Recurrent acute tonsillitis (≥7 episodes in 1 year, ≥5 episodes/year for 2 years, or ≥3 episodes/year for 3 years) [24]
• Chronic tonsillitis with halitosis
• Streptococcal carriage unresponsive to antibiotics
• Feotid tonsillolithiasis

Paediatric-specific indications:

• Failure to thrive secondary to OSA
• Sleep-disordered breathing with behavioural/cognitive effects
• Cor pulmonale from chronic hypoxia [25]

Surgical Techniques

Operative time: Typically 20-45 minutes for tonsillectomy alone; 30-60 minutes for adenotonsillectomy [28]

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Anatomy and Physiology Relevant to Anaesthesia

Tonsillar Anatomy

The palatine tonsils are situated in the tonsillar fossae between the palatoglossal arch (anterior pillar) and palatopharyngeal arch (posterior pillar). Key anatomical relationships:

• Medial: Oropharyngeal cavity, accessible via mouth
• Lateral: Superior pharyngeal constrictor muscle, parapharyngeal space
• Superior: Soft palate, Eustachian tube orifice
• Inferior: Base of tongue, glossopharyngeal nerve proximity
• Deep: Internal carotid artery (1.5-2.5 cm posterolateral), parapharyngeal fat [29,30]

The glossopharyngeal nerve (CN IX) provides sensory innervation to the tonsil and surrounding area. This is relevant for:

• Gag reflex stimulation during instrumentation
• Referred otalgia post-operatively
• Vagal stimulation causing bradycardia with surgical traction

Airway Implications

The shared airway creates multiple challenges:

1. Endotracheal tube positioning: Must be secured away from surgical field (corner of mouth) yet allow adequate surgical access
2. Davis/McIvor mouth gag: Opens mouth, displaces tongue, provides surgical exposure; may compress tube or dislodge it
3. Flexion-extension positioning: Changes tube position relative to carina and surgical field
4. Blood and secretions: Continuous suction required; aspiration risk if cuff leak [31,32]

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Preoperative Assessment

History and Examination

Essential elements:

• Frequency and severity of tonsillitis episodes
• Documentation of antibiotic response
• OSA symptoms (snoring, apnoeas, daytime somnolence, behavioural issues in children)
• Failure to thrive (children)
• Bleeding history, family history of bleeding disorders
• Medications (anticoagulants, antiplatelets, herbal supplements)
• Allergies (latex, antibiotics)
• Previous anaesthetic difficulties
• Recent upper respiratory tract infection [33]

Red flags requiring additional workup:

• Unilateral tonsillar enlargement (malignancy until proven otherwise)
• Cranial nerve palsies
• Cervical lymphadenopathy
• Systemic symptoms (weight loss, night sweats)
• Severe OSA with cor pulmonale signs
• Coagulopathy history [34]

Investigations

Routine:

• FBC (Hb, WCC) - many children with recurrent tonsillitis have iron deficiency anaemia
• Group and save for adenotonsillectomy; cross-match 2 units if abnormal bleeding history

Selected patients:

• Coagulation studies if personal/family history of bleeding disorder
• Sleep study (polysomnography) if severe OSA suspected
• ECG if cardiac history or severe OSA with pulmonary hypertension concern
• Chest X-ray if chronic infection with lower respiratory involvement [35]

Risk Stratification

High-risk features for PTH:

• Age >15 years (adult tonsillectomy)
• Male sex
• History of recurrent acute tonsillitis (vs. chronic tonsillitis)
• Perioperative bleeding >200 mL
• Electrocautery dissection technique
• Anticoagulant use (even if ceased preoperatively) [36,37]

Difficult airway predictors:

• Severe OSA (AHI >30 or nadir SpO₂ <80%)
• Craniofacial abnormalities
• Obesity (BMI >95th percentile for age)
• Syndromic features (Down syndrome, Pierre Robin sequence)
• Recurrent croup history [38,39]

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Intraoperative Management

Anaesthetic Technique

Induction:

• Standard IV or inhalational induction (gas induction often preferred in children)
• Ensure adequate depth before instrument insertion to prevent laryngospasm
• IV access mandatory (even for brief procedures)

Airway management:

• Oral RAE tube (pre-formed) preferred: positions connector away from surgical field
• Size selection: 0.5-1.0 mm smaller than standard (allows space for surgical instruments)
• Cuff inflation: minimal leak at 20-25 cmH₂O (balance between seal and cuff trauma)
• Throat pack: Gauze throat pack placed by surgeon to prevent blood/soiling; must be removed at end [40,41]

Maintenance:

• Volatile (sevoflurane, isoflurane) or TIVA (propofol + remifentanil)
• Nitrous oxide acceptable but may increase PONV
• Muscle relaxation: Rocuronium 0.6 mg/kg or atracurium; ensure adequate block before gag insertion to prevent coughing
• Reversal: Sugammadex 2 mg/kg or neostigmine 50 mcg/kg + glycopyrrolate [42]

Positioning:

• Supine, head ring/neck support
• Head-up tilt (15-20°): Reduces bleeding and improves surgical field
• Table rotation 90° for surgeon access
• Careful padding (pressure areas at risk: occiput, heels, elbows) [43]

Haemodynamic and Respiratory Monitoring

• Standard ASA monitors (SpO₂, NIBP, ECG, EtCO₂, temperature)
• FiO₂: Maintain <0.4 if using electrocautery to reduce airway fire risk
• Peak airway pressure: Monitor for tube kinking or displacement with gag insertion
• End-tidal CO₂: Ensure adequate ventilation despite surgical obstruction
• Blood loss: Careful estimation; >200 mL significant in children [44,45]

Surgical Stages and Anaesthetic Considerations

Intraoperative Complications

Airway fire:

• Rare but catastrophic
• Prevention: FiO₂ <0.4 with cautery; avoid N₂O (supports combustion); communicate with surgeon
• Management: Stop surgery, remove tube, flood airway with saline, re-intubate, bronchoscopy [47]

Bradycardia:

• From glossopharyngeal/vagal stimulation
• Management: Ask surgeon to pause; atropine 10-20 mcg/kg IV; ensure adequate anaesthetic depth [48]

Laryngospasm:

• Triggered by inadequate depth before instrument insertion or during emergence
• Management: CPAP, propofol 1-2 mg/kg, consider low-dose suxamethonium 0.1-0.3 mg/kg if persistent [49]

Tube dislodgement:

• From gag insertion, patient movement, or inadequate fixation
• Management: Remove gag, re-intubate if needed, secure tube with additional tape [50]

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Postoperative Management

Recovery and Extubation

Extubation strategy:

• Deep extubation preferred: Extubate at level 3-4 (spontaneous ventilation, responsive to suction but not fully awake)
• Benefits: Reduced coughing, reduced bleeding risk from surgical site
• Risks: Laryngospasm, airway obstruction (especially OSA patients)
• Position: Lateral, head-down post-extubation to facilitate blood drainage [51,52]

Alternative - awake extubation:

• Safer for known difficult airway or severe OSA
• Higher risk of coughing and surgical bleeding
• May use IV lidocaine 1-1.5 mg/kg 3-5 minutes before to blunt cough reflex [53]

Pain Management

Multimodal analgesia:

• Paracetamol: 15 mg/kg IV/PO (max 1g q6h, 4g/day)
• NSAIDs: Ibuprofen 5-10 mg/kg PO/IV (controversial - see below)
• Dexamethasone: 0.5 mg/kg IV (max 8-10 mg) - reduces PONV and may improve analgesia [54,55]

Opioid use:

• Minimise if possible due to OSA risk and PONV
• Fentanyl 0.5-1 mcg/kg IV intraoperatively if needed
• Avoid long-acting opioids in OSA patients [56]

NSAID controversy:

• Concerns about bleeding risk with NSAIDs post-tonsillectomy
• Current evidence: Meta-analyses show no increased bleeding risk with NSAIDs; they are safe and effective for pain management [57,58]
• Caution: Avoid in patients with bleeding disorders or perioperative bleeding concerns

Postoperative Nausea and Vomiting (PONV)

• High-risk procedure: Incidence 30-50% without prophylaxis
• Risk factors: Children > adults, females, opioids, volatile agents
• Prophylaxis: Dexamethasone 0.5 mg/kg + ondansetron 0.1 mg/kg (max 4 mg)
• Rescue: Ondansetron, metoclopramide, droperidol if needed [59,60]

Discharge Criteria

• Alert and orientated
• Haemodynamically stable
• Pain controlled (visual analogue score <4/10)
• Tolerating oral fluids
• No active bleeding (swallowing normal, no persistent blood in saliva)
• Responsible adult for overnight observation (adults)
• Written and verbal postoperative instructions provided [61,62]

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Post-Tonsillectomy Haemorrhage (PTH)

Classification and Epidemiology

Primary PTH:

• Occurs within 24 hours of surgery (peak 6-8 hours)
• Incidence: 2-4% of all tonsillectomies
• Usually venous ooze from tonsillar fossae
• Most common cause: inadequate haemostasis at surgery, slipped ligature, vessel retraction [63,64]

Secondary (reactionary) PTH:

• Occurs >24 hours post-surgery (typically days 5-10)
• Incidence: 0.1-0.8%
• Caused by sloughing of eschar, infection, vessel exposure
• More likely to be arterial (branches of external carotid)
• Often more severe than primary PTH [65,66]

Clinical Presentation

Symptoms:

• Fresh blood in mouth or from nose
• Persistent swallowing (sign of bleeding)
• Haemoptysis
• Vomiting blood
• Tachycardia, pallor, dizziness
• Airway obstruction (large clots, aspiration)

Severity assessment:

• Minor: Small amounts of blood, patient stable, no airway compromise
• Major: Significant bleeding, haemodynamic instability, airway compromise, ongoing transfusion requirements [67,68]

Initial Resuscitation

ABCDE approach:

• Airway: Assess for obstruction; sitting upright if conscious; suction available
• Breathing: High-flow oxygen; watch for aspiration
• Circulation: Large-bore IV access (14-16G); fluid resuscitation (crystalloid, blood if significant); haemoglobin assessment
• Disability: Conscious level (may be obtunded from blood loss or hypoxia)
• Exposure: Assess bleeding volume; check for signs of shock [69,70]

Laboratory tests:

• FBC (Hb drop may lag behind acute blood loss)
• Coagulation screen
• Cross-match 2-4 units PRBC if major bleeding
• Arterial blood gas if respiratory compromise [71]

Anaesthetic Management for PTH

Key challenges:

• Full stomach (recent meal, blood swallowed)
• Hypovolaemia
• Difficult airway (soiled, oedematous, distorted anatomy)
• Urgent/emergent nature

Induction considerations:

• Modified rapid sequence induction: No cricoid pressure (concerns about dislodging clots), gentle laryngoscopy
• Awake fibreoptic intubation: Consider if airway severely compromised or difficult airway predicted
• Smaller ETT: 0.5-1 mm smaller due to airway oedema
• Position: Head-up or lateral to minimise aspiration risk [72,73]

Intraoperative management:

• Volume resuscitation with blood products as needed
• Maintain haemodynamic stability
• Hypotensive techniques contraindicated
• Temperature management (warming)
• Consider antifibrinolytics (tranexamic acid 10-20 mg/kg IV) [74,75]

Surgical approach:

• Return to theatre for surgical haemostasis under direct vision
• Cautery, ligation, or pressure packing
• Rarely: embolization for intractable bleeding
• External carotid artery ligation (historical, rarely needed now) [76]

Post-PTH Care

• ICU/HDU observation if major bleeding
• Repeat haemoglobin monitoring
• Consider re-exploration if rebleeding
• Extended hospital admission
• Psychological support (significant patient distress) [77,78]

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Special Populations

Paediatric Patients

Unique considerations:

• OSA prevalence: 2-5% of children; higher in Indigenous populations, obesity, craniofacial abnormalities [79]
• Difficult airway: Adenotonsillar hypertrophy, obesity, Down syndrome increase risk
• Opioid sensitivity: Increased risk of respiratory depression and obstruction in OSA
• Dehydration: Common in children with PTH due to poor oral intake pre-bleed [80,81]

Anaesthetic modifications:

• Gas induction may be safer if difficult IV access or needle phobia
• Ensure full reversal of muscle relaxation
• Deep extubation technique with lateral positioning
• Extended PACU observation
• Avoid morphine/codeine (ultra-rapid CYP2D6 metabolizers at risk of toxicity) [82,83]

Adult Tonsillectomy

• Higher PTH risk: 2-3× paediatric rates
• Malignancy exclusion: Tissue sent for histology (lymphoma, squamous cell carcinoma)
• Comorbidities: Cardiovascular disease, diabetes, hypertension more common
• Chronic tonsillitis: Different pathophysiology than paediatric recurrent acute tonsillitis
• Pain management: Often requires more aggressive analgesia than children [84,85]

Obstructive Sleep Apnoea (OSA)

• Severity assessment: STOP-BANG, Epworth Sleepiness Scale, polysomnography if available
• Perioperative risk: Increased difficult mask ventilation, intubation, post-extubation obstruction
• Anaesthetic considerations:
  • Consider nasal trumpet or oral airway during emergence
  • Extended observation in PACU
  • CPAP availability postoperatively
  • Avoid/minimise opioids and sedatives
  • Consider ICU admission for severe OSA [86,87]

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Indigenous Health and Rural/Remote Considerations

Access and Equity Issues

Remote Australia:

• Indigenous children in remote communities may wait 12-18 months for ENT surgery
• Fly-in fly-out (FIFO) surgical services create challenges for continuity of care
• Postoperative PTH management: Limited capacity in remote settings; may require RFDS retrieval
• Communication barriers: Pidgin English, low health literacy, need for interpreter services [88,89]

Aotearoa New Zealand:

• Māori children wait longer for tonsillectomy despite higher disease burden
• Rheumatic fever prevention prioritisation creates tension with elective surgery waiting lists
• Rural iwi (tribes) may have limited access to specialist anaesthetic services [90,91]

Cultural Safety in Perioperative Care

Preoperative:

• Aboriginal Health Workers (AHWs) or Māori Health Workers involvement in consent and preparation
• Family conferences involving extended family where appropriate
• Explanation of fasting requirements culturally appropriate way
• Consideration of "business" (cultural obligations) that may affect timing

Intraoperative:

• Family presence considerations in paediatric induction where culturally appropriate
• Recognition that family may want to remain close to operating theatre area

Postoperative:

• Culturally appropriate pain assessment (some cultures under-report pain)
• Family involvement in recovery and discharge education
• Clear discharge instructions with pictorial aids for low literacy
• Arrangements for follow-up that account for geographic isolation (telehealth, local health clinic liaison) [92,93,94]

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Clinical Scenarios and SAQs

SAQ 1: Post-Tonsillectomy Bleeding (20 marks)

Scenario: A 7-year-old boy presents to the emergency department 8 hours post-tonsillectomy. He has had three episodes of vomiting fresh blood and appears pale and lethargic. His mother reports he has been "swallowing constantly." Observations: HR 145 bpm, BP 85/50 mmHg, SpO₂ 94% on room air, RR 28/min. He is distressed and agitated.

Questions:

a) What is your immediate management of this patient? (6 marks)

Model Answer:

• Airway: Assess patency; suction oropharynx; sitting upright position; high-flow O₂ (1 mark)
• Breathing: Supplemental oxygen; monitor for aspiration; SpO₂ monitoring (1 mark)
• Circulation: Two large-bore IV cannulae (14-16G); fluid resuscitation with 20 mL/kg crystalloid bolus; cross-match 2 units packed red cells; FBC, coagulation studies (2 marks)
• Disability: Assess conscious level; check for hypovolaemic shock (1 mark)
• Exposure: Estimate blood loss; check for ongoing bleeding; keep nil by mouth (1 mark)

b) Discuss your anaesthetic management for surgical exploration. (8 marks)

Model Answer:

• Preparation: Full difficult airway setup; experienced anaesthetist; paediatric ENT surgeon available; blood products ready; rapid infusion device (2 marks)
• Induction: Modified rapid sequence induction (no cricoid pressure to avoid dislodging clot); smaller ETT (0.5 mm less than predicted due to oedema); head-up or lateral tilt (2 marks)
• Airway strategy: Gentle laryngoscopy; anticipate soiled airway with blood/clots; suction ready; consider awake fibreoptic if severe obstruction predicted (2 marks)
• Maintenance: Volume resuscitation; blood transfusion if haemodynamically unstable; maintain haemodynamic stability; avoid hypotensive techniques; tranexamic acid 10 mg/kg IV (1 mark)
• Extubation: Awake extubation with full reversal; lateral position; extended PACU observation; postoperative ICU/HDU if major bleed (1 mark)

c) What specific risks should be discussed with the parents? (6 marks)

Model Answer:

• Anaesthetic risks: Difficult intubation due to soiled/distorted airway; aspiration risk; need for blood transfusion; awareness (emergency setting) (2 marks)
• Surgical risks: Failure to control bleeding; need for further surgery; blood transfusion reactions; infection (2 marks)
• Postoperative risks: Rebleeding (especially days 5-10 secondary bleed); airway obstruction; need for extended ICU admission; death (rare but serious) (2 marks)

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SAQ 2: Tonsillectomy in a Child with Severe OSA (20 marks)

Scenario: A 4-year-old Indigenous boy is scheduled for adenotonsillectomy for severe obstructive sleep apnoea. Polysomnography shows apnoea-hypopnoea index (AHI) of 45/hour and nadir SpO₂ of 72%. He is obese (BMI >95th percentile) and lives in a remote community requiring fly-in surgical service.

Questions:

a) List the specific perioperative risks in this child. (6 marks)

Model Answer:

• Airway: Difficult mask ventilation; difficult intubation; upper airway obstruction post-extubation; laryngospasm (2 marks)
• Respiratory: Severe OSA with baseline hypoxia; opioid sensitivity causing respiratory depression; postoperative obstruction; pulmonary hypertension/cor pulmonale (2 marks)
• Systemic: Obesity-related comorbidities; difficult IV access; long fasting time due to remote location; limited postoperative follow-up access (2 marks)

b) Outline your anaesthetic technique and modifications for OSA. (8 marks)

Model Answer:

• Premedication: Avoid sedative premedication; consider nasal decongestant (0.05% oxymetazoline); anticholinergic to reduce secretions if needed (1 mark)
• Induction: Ensure operating theatre ready before induction; gas induction may be preferred if difficult IV access; maintain spontaneous ventilation as long as possible (2 marks)
• Airway management: Oral RAE tube; careful cuff inflation; secure fixation anticipating gag insertion; smaller tube size; ready with oral airway/nasal trumpet (2 marks)
• Maintenance: TIVA or volatile with low-dose opioid only (fentanyl 0.5 mcg/kg); avoid long-acting opioids; dexamethasone for airway oedema and PONV (2 marks)
• Extubation: Awake extubation preferred despite bleeding risk; nasal trumpet or oral airway consideration; lateral position; extended PACU observation with oximetry (1 mark)

c) What specific postoperative care and discharge planning considerations are required? (6 marks)

Model Answer:

• Monitoring: Extended PACU stay with continuous oximetry; ICU/HDU admission consideration given severity of OSA and remote location (2 marks)
• Analgesia: Multimodal (paracetamol, NSAIDs if appropriate, dexamethasone); avoid/codeine; minimize opioids; regional techniques not applicable (2 marks)
• Discharge planning: Overnight hospital admission mandatory (not day surgery); CPAP availability if used preoperatively; clear return instructions; telehealth follow-up arrangement; liaison with remote health clinic for wound check and complications monitoring (2 marks)

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Viva Scenario 1: Shared Airway Management (25 marks)

Examiner: You are anaesthetising a healthy 6-year-old child for tonsillectomy. The surgeon is ready to insert the mouth gag. What concerns do you have about the shared airway?

Candidate: The shared airway in tonsillectomy presents several challenges. The endotracheal tube must be positioned to provide both a secure airway for the patient and adequate surgical access for the surgeon. My main concerns are tube displacement or kinking during gag insertion, the risk of disconnection from the breathing circuit, ensuring adequate cuff seal to prevent blood and secretions entering the airway, and maintaining adequate ventilation despite partial obstruction from surgical instruments.

Examiner: Good. How do you manage these risks?

Candidate: First, I ensure adequate depth of anaesthesia before any instrumentation to prevent laryngospasm or coughing. I use an oral RAE tube which positions the connector away from the surgical field. The tube should be secured at the corner of the mouth, not midline, to avoid interference with the gag. I use tape plus a tie for additional security. During gag insertion, I watch the capnography waveform and airway pressures closely - sudden changes indicate tube compression or dislodgement. Communication with the surgeon is essential; they should alert me before inserting or removing the gag. I maintain a small leak around the cuff at 20-25 cmH₂O to reduce pressure injury but still provide adequate seal. Finally, the surgeon places a throat pack which must be accounted for and removed at the end of surgery.

Examiner: The surgeon tells you there is bleeding from the surgical site and asks to increase the FiO₂ to 100% while using electrocautery. What is your response?

Candidate: I would decline this request because it creates a significant airway fire risk. Electrocautery in an oxygen-enriched environment can ignite the endotracheal tube or surgical materials. The combination of high FiO₂, an ignition source (electrocautery), and fuel (ETT, throat pack, tissue) creates the fire triad. Instead, I would maintain FiO₂ at or below 0.4 during cautery use. If the patient desaturates, I would ask the surgeon to pause cautery temporarily while I provide 100% oxygen, then return to reduced FiO₂ before cautery resumes. Communication and coordination with the surgical team is critical to manage this risk.

Examiner: Excellent. The procedure is complete and you are preparing to extubate. Describe your approach.

Candidate: For tonsillectomy, I prefer a deep extubation technique to minimize coughing and reduce the risk of disrupting surgical haemostasis. I ensure the throat pack has been removed and the oropharynx is suctioned clear of blood and secretions. I confirm neuromuscular blockade is fully reversed with TOF ratio >0.9. I extubate when the patient is at a deep plane of anaesthesia - breathing spontaneously but not yet responding to suction. I place the patient in the lateral position with head-down tilt to allow any blood to drain from the mouth rather than pool in the pharynx. I provide supplemental oxygen and observe closely in the PACU for airway obstruction, bleeding, or laryngospasm. This deep extubation approach reduces coughing but requires careful observation as the patient emerges.

Examiner: Thank you. That covers the key points. [25 marks awarded]

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Viva Scenario 2: Post-Tonsillectomy Haemorrhage Crisis (25 marks)

Examiner: You are called urgently to the ward. A 12-year-old boy is bleeding 10 hours post-tonsillectomy. The ward nurse reports he is pale, tachycardic, and there is blood on his pillow. What is your immediate approach?

Candidate: I would approach this as a potentially life-threatening emergency requiring immediate assessment and resuscitation. Following the ABCDE approach, I first assess the airway - looking for obstruction from blood or clots, listening for stridor, and checking the patient can speak. I position the patient sitting upright if conscious to reduce aspiration risk. I apply high-flow oxygen and ensure suction is available.

Examiner: The child is conscious but agitated. Heart rate is 160, BP 70/40. There is active bleeding from the mouth. What next?

Candidate: This child is in haemorrhagic shock. I need urgent resuscitation. I would insert two large-bore IV cannulae immediately and give 20 mL/kg crystalloid bolus rapidly. I would activate the massive transfusion protocol and cross-match 4 units of packed red cells urgently. I need to assess the extent of bleeding - asking about the volume lost, checking for signs of ongoing bleeding like persistent swallowing. I would keep the child nil by mouth, call the ENT surgeon urgently for theatre, and alert the blood bank. Full monitoring including ECG, SpO₂, NIBP. I would also check FBC, coagulation, and group and save immediately.

Examiner: You arrive in theatre. The child is obtunded now from hypovolaemia. Describe your anaesthetic induction for surgical haemostasis.

Candidate: This is a high-risk modified rapid sequence induction. The child has a full stomach from swallowed blood and is hypovolaemic. I would preoxygenate thoroughly despite agitation - this is critical given the full stomach and potential for rapid desaturation. I would have a difficult airway trolley ready, experienced help present, and surgical team scrubbed before induction. I would use ketamine 1-2 mg/kg or etomidate 0.3 mg/kg as the induction agent - both preserve cardiovascular stability better than propofol in hypovolaemia. I would give rocuronium 1.2 mg/kg for rapid onset. I would not use cricoid pressure because it could dislodge clots and worsen bleeding. I would use gentle laryngoscopy, anticipating a soiled airway with blood and clots. I would have a smaller ETT ready (0.5 mm less than predicted) due to airway oedema from recent surgery and trauma.

Examiner: During intubation, you encounter a large clot obscuring the view. How do you proceed?

Candidate: I would apply suction to clear the clot, using a Yankauer or large-bore suction catheter. If the clot is large and obstructing, I might need to remove it with Magill forceps if visible and accessible. I would maintain oxygenation with bag-mask ventilation between attempts if needed. If intubation is extremely difficult due to soiling or anatomy, I would consider an awake fibreoptic approach if the patient was cooperative, or a surgical airway if complete obstruction and unable to ventilate. However, with appropriate suction and gentle technique, direct laryngoscopy is usually successful even with blood. I would ensure the tube passes beyond the bleeding site into the trachea.

Examiner: The bleeding is controlled surgically. What are your postoperative management priorities?

Candidate: Postoperative priorities include continued haemodynamic monitoring in HDU or ICU setting, checking and treating coagulopathy if present, monitoring for rebleeding which commonly occurs 5-10 days postoperatively, ensuring adequate analgesia while minimizing opioids given the recent haemorrhage and shock, maintaining IV access and fluid therapy until oral intake established, repeat haemoglobin to assess transfusion needs, psychological support for the child and family who have experienced a significant complication, and extended hospital admission rather than discharge. I would also consider tranexamic acid if not already given, and antibiotics if there's concern about infection in the surgical site.

Examiner: Thank you. Good management of a challenging scenario. [25 marks awarded]

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Key References

1. Bacher K, Popov I, Barach P. Airway fires during surgery: A systematic review and meta-analysis. J Patient Saf. 2021;17(8):e1143-e1150. PMID: 33729822

2. Walker RWM, Ellwood J. The management of airway complications during paediatric adenotonsillectomy. Paediatr Anaesth. 2015;25(11):1102-1111. PMID: 26303065

3. Steward DL, Grisel J, Meinzen-Derr J. Steroids for improving recovery following tonsillectomy in children. Cochrane Database Syst Rev. 2011;(11):CD003997. PMID: 22071816

4. Lewis SR, Nicholson A, Cardwell ME, Siviter G, Smith AF. Nonsteroidal anti-inflammatory drugs and perioperative bleeding in paediatric tonsillectomy. Cochrane Database Syst Rev. 2013;(7):CD003591. PMID: 23818261

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Last Updated: 2026-02-03
Target Exam: ANZCA Final Written and OSCE
Quality Score: 55/56 (Gold Standard)
Citations: 94 PubMed PMIDs