Anaesthesia for Day Surgery

Quick Answer

Day surgery (ambulatory surgery) requires rapid, smooth emergence, effective analgesia allowing oral intake and mobility, minimal PONV, and safe discharge. Patient selection: ASA I-III generally acceptable, BMI <35-40 (individualized), age >6 months (some procedures to 3 months), no severe OSA (unless simple procedure), no severe cardiorespiratory disease. Premedication: Anxiolysis if needed (midazolam 1-2 mg IV or 0.05 mg/kg PO in children), multimodal antiemetic prophylaxis essential. Anaesthetic technique: Propofol TIVA (faster emergence, less PONV), short-acting opioids (fentanyl, remifentanil), avoid long-acting drugs, regional techniques preferred where appropriate (spinal, caudal, peripheral blocks), avoid N₂O (may increase PONV). Emergence: Rapid, no airway obstruction, pain controlled, nausea minimal. Discharge criteria: Modified Aldrete score >9, vitals stable, pain <4/10, no nausea, can ambulate (if applicable), voided (if indicated), escort present, written instructions given. [1-10]

Patient Selection

Criteria for Day Surgery

Medical Status:

• ASA classification: I-III acceptable (III with optimization)
• Age:
  • Adults: No upper limit if healthy
  • Pediatrics: >6 months generally (some centers >3 months for minor procedures)
  • Premature infants: Post-conceptual age >60 weeks for general anaesthesia
• BMI: <35-40 kg/m² (individualized based on procedure and comorbidities)
• Cardiovascular: Stable CAD, controlled hypertension, no recent MI (<6 weeks), no unstable arrhythmias
• Respiratory: Controlled asthma/COPD, no severe OSA (relative contraindication unless simple procedure), no recent respiratory infection
• Diabetes: Well-controlled, on stable regimen

Social Criteria:

• Escort: Responsible adult to accompany home and stay overnight
• Transport: Private car preferred (no public transport alone)
• Home environment: Telephone access, not alone overnight, appropriate care available
• Geography: Within reasonable distance of hospital (<1 hour ideally)

Procedure Criteria:

• Duration: <2 hours typically (longer if appropriate)
• Blood loss: Minimal to moderate
• Pain: Controllable with oral analgesics
• Complexity: Low to moderate (no major complications expected)
• Postoperative care: Does not require intensive monitoring

Contraindications (Relative)

Absolute Contraindications:

• No escort or responsible adult
• No access to emergency care (remote location without transport)
• Uncontrolled medical conditions
• Patient refusal or inability to comply with instructions

Relative Contraindications:

• Severe OSA: Risk of airway obstruction postoperatively (may be acceptable for superficial procedures with local/regional)
• Morbid obesity: Individual assessment (BMI >40 high risk)
• Advanced age: >85 years (higher complication risk)
• Cognitive impairment: Cannot follow instructions
• Language barrier: Cannot understand discharge instructions
• Chronic pain/opioid tolerance: Difficult to control pain with oral meds alone
• Anticoagulation: For procedures with bleeding risk (bridge or stop as appropriate)
• Previous PONV: High risk for recurrence

Preoperative Assessment

Timing:

• Assessment: Day of surgery or pre-admission clinic
• Screening: Phone triage for healthy patients

Key Elements:

• History: Medical conditions, medications, allergies, previous anaesthetic problems (PONV, MH, difficult airway)
• Examination: Airway assessment, cardiorespiratory, baseline vitals
• Investigations:
• Minimal for healthy patients
• Hb if anticipated blood loss
• ECG if >50 years or cardiac history
• Glucose if diabetic
• Pregnancy test if reproductive age (per institutional policy)
• Fasting: 6 hours solids, 2 hours clear fluids (encourage clear fluids up to 2 hours)
• Medications: Continue usual medications (antihypertensives, cardiac, asthma) with sip of water

Anaesthetic Technique

Premedication

Anxiolysis:

• Adults: Midazolam 1-2 mg IV or 0.05 mg/kg PO
• Children: Midazolam 0.5 mg/kg PO (max 15-20 mg), intranasal 0.2-0.3 mg/kg
• Timing: 30-45 minutes before surgery (PO), 5-10 minutes (IV)

Analgesia:

• Paracetamol: 1 g PO/PR/IV (pre-emptive)
• NSAIDs: Celecoxib 200-400 mg PO (if no contraindication)
• Gabapentinoids: Pregabalin 75-150 mg PO (reduces opioid needs)

Antiemetics:

• Prophylaxis mandatory: Day surgery has high PONV risk
• Multimodal approach:
• Dexamethasone 4-8 mg IV (at induction)
• Ondansetron 4 mg IV (at end)
• Consider: Droperidol 0.625-1.25 mg, palonosetron, aprepitant for high risk
• TIVA: Propofol reduces PONV 30% vs volatile

Induction

Intravenous:

• Propofol: 2-3 mg/kg (most common)
• Rapid onset, smooth emergence, antiemetic properties
• Pain on injection (prevent with lidocaine 20-40 mg or use larger vein)
• Etomidate: If hemodynamic concern (adrenally suppressed if infusion)
• Ketamine: 1-2 mg/kg (pediatrics, hemodynamically unstable, good for pain)

Inhalational:

• Sevoflurane: For children (non-pungent, rapid)
• Avoid: Desflurane (airway irritation), N₂O (may increase PONV)

Muscle Relaxation:

• Succinylcholine: 1 mg/kg for RSI (intubation), rapid offset
• Rocuronium: 0.6 mg/kg (sugammadex allows rapid reversal)
• Avoid: Long-acting relaxants (pancuronium)
• Reversal: Sugammadex preferred (16 mg/kg for immediate, 2-4 mg/kg standard), faster than neostigmine

Maintenance

TIVA (Preferred for Day Surgery):

• Propofol: 100-200 μg/kg/min + remifentanil 0.05-0.2 μg/kg/min
• Advantages: Rapid clear-headed emergence, less PONV, euphoric recovery
• Advantages over volatile: Faster wake-up, less nausea, less cognitive impairment
• Monitoring: BIS 40-60 (prevents under/overdose)

Balanced Anaesthesia:

• Volatile: Sevoflurane 0.5-1 MAC (avoid desflurane - pungent, sympathomimetic)
• Avoid N₂O: May increase PONV, bowel distension, pneumothorax risk (laparoscopy)
• Opioids: Short-acting
• Fentanyl 1-2 μg/kg boluses (duration 30-60 min)
• Remifentanil infusion (ultra-short, context-insensitive)
• Avoid morphine (long-acting, nausea)

Regional Techniques (Preferred when appropriate):

• Spinal: Bupivacaine 7.5-10 mg (short duration)
• Epidural/caudal: Short-acting LA, no opioid
• Peripheral blocks:
• Upper limb: Axillary, supraclavicular (long-acting LA acceptable)
• Lower limb: Femoral, popliteal, ankle
• Trunk: TAP, rectus sheath, paravertebral
• Benefits: Superior analgesia, reduced opioid needs, faster recovery, less PONV

Intraoperative Management

Fluid Management:

• Restrictive approach: Evidence suggests less is more in day surgery
• Maintenance: 2-4 mL/kg/hour (reduced from historical 10-15 mL/kg/hour)
• Blood loss: Replace if >300-500 mL (consider discharge hematocrit)
• Goal: Urine output not mandatory unless long procedure

Temperature:

• Active warming: Forced air warmer (large heat loss even short procedures)
• Monitor: Maintain >36°C
• Hypothermia: Delays emergence, shivering (uncomfortable), coagulopathy

Glucose:

• Maintain 6-10 mmol/L
• Diabetic patients: Monitor frequently, adjust insulin
• Avoid hypoglycemia: More dangerous than mild hyperglycemia

Emergence

Goals:

• Rapid: <10-15 minutes from stopping anaesthetic
• Clear-headed: Oriented, minimal confusion
• Comfortable: Pain <4/10, no nausea
• Safe airway: Swallowing, cough reflex returned

Technique:

• Stop agents early: Allow wash-out
• Propofol: Rapid offset (context-sensitive halftime 30-40 min even after 2 hours)
• Reversal:
• Sugammadex for rocuronium (16 mg/kg immediate, 2-4 mg/kg standard)
• Neostigmine if sugammadex unavailable
• Lidocaine: 1 mg/kg IV (reduces coughing on tube, reduces airway irritability)

Extubation:

• Awake: Eyes open, following commands (safer for day surgery)
• LMA: Can remove deep if airway easy (less coughing)
• Airway: Ensure patency before leaving OR

Postoperative Care

Phase 1 Recovery (PACU)

Monitoring:

• Vitals: q15 min initially, then q30 min
• Aldrete score: Every 15 min until >9
• Pain: 0-10 scale
• Nausea: 0-3 scale
• Oxygen: SpO₂ >94% on room air before discharge

Pain Management:

• Multimodal:
• Paracetamol: 1 g q6h (max 4 g/day)
• NSAIDs: If no contraindication (ibuprofen 400 mg q6h, celecoxib 200 mg BD)
• Opioids: Oxycodone 5-10 mg q4-6h PRN (short course)
• Regional: Continue block (warn about motor weakness)
• Goal: Pain <4/10 at rest, <6/10 with movement

Nausea/Vomiting Management:

• Rescue antiemetics:
• Ondansetron 4 mg IV (repeat once if needed)
• Droperidol 0.625-1.25 mg IV (effective but QT prolongation/sedation)
• Dexamethasone 4 mg IV (if not given)
• Metoclopramide 10 mg (less effective, EPS risk)
• Refractory: Admit for overnight observation

Phase 2 Recovery (Step-down/Discharge Area)

Criteria for Phase 2:

• Aldrete score >9
• Vitals stable × 30 min
• Pain controlled with oral meds
• Tolerating oral fluids (if required - not mandatory for all)
• Voided (if spinal/epidural, or institutional requirement)
• Dressing dry

Oral Intake:

• Traditional: Mandatory drink before discharge
• Modern approach: Not mandatory for all (clear fluids encouraged, solids not required)
• Exceptions: Patients prone to dehydration (elderly), diabetes

Voiding:

• Required after spinal: Must void before discharge (neuraxial block)
• Not required for GA: Can discharge without voiding if comfortable, no distension

Discharge Criteria:

Modified Aldrete Score (target >9):

1. Activity: Able to move voluntarily/on command (2), limited movement (1), no movement (0)
2. Respiration: Deep breath/cough (2), dyspnea/shallow (1), apneic (0)
3. Circulation: BP ±20% baseline (2), ±20-50% (1), ±>50% (0)
4. Consciousness: Fully awake (2), arousable (1), not responding (0)
5. O₂ saturation: >92% room air (2), needs O₂ (1), <90% even with O₂ (0)

Additional Requirements:

• Pain: <4/10
• Nausea: None or minimal
• Bleeding: None
• Dizziness: None on standing
• Escort: Present and informed
• Instructions: Written and verbal provided

Post-Discharge Care

Instructions:

• Activity: Rest, gradual return to normal over 24-48 hours
• Diet: Light initially, advance as tolerated
• Medications:
• Analgesia schedule (not just PRN for first 24-48 hours)
• Resume usual medications
• Wound care: Keep dry 24-48 hours, watch for infection
• Red flags: Bleeding, fever, severe pain, vomiting, breathing difficulty → seek help
• Follow-up: Appointment date, contact number
• Emergency: 24-hour contact number provided

Rescue Analgesia:

• Breakthrough pain: Oxycodone 5-10 mg q4-6h (limited supply)
• Severe pain: Contact facility or ED

Driving:

• Prohibition: 24 hours minimum (insurance/liability)
• Judgment: Coordination, reaction time impaired
• Machinery: Same restriction

Complications to Monitor:

• Delayed PONV: 24-48 hours post-discharge (provide antiemetic prescription)
• Bleeding: Wound, internal (orthopaedic)
• Infection: Increasing pain, fever, erythema
• Urinary retention: After spinal/epidural
• Falls: Elderly, post-op confusion

Special Populations

Pediatric Day Surgery

Specific Considerations:

• Age: >3-6 months typically (premature infants to 60 weeks post-conceptual age)
• Premedication: Midazolam 0.5 mg/kg PO (sweetened)
• Anaesthesia: Sevoflurane inhalational or propofol TIVA
• Analgesia:
• Paracetamol 15 mg/kg
• NSAIDs: Ibuprofen 10 mg/kg (if >6 months), ketorolac 0.5 mg/kg
• Regional: Caudal 0.25% bupivacaine 0.5-1 mL/kg, penile block, ilioinguinal
• PONV prophylaxis: TIVA, dexamethasone 0.15 mg/kg (max 10 mg), ondansetron 0.15 mg/kg
• Discharge:
• Drinking (more important than adults - risk dehydration)
• Pain controlled
• Parents escort

Elderly Day Surgery

Specific Considerations:

• Assessment: Cognitive baseline (delirium risk), frailty
• Anaesthesia: TIVA (less PONV, less delirium than volatile)
• Analgesia: Avoid NSAIDs (renal, GI), cautious with opioids
• Regional: Preferred (reduces systemic drug load)
• Discharge: Ensure home support, clear instructions (memory aids)
• Complications: Higher PONV, delirium, falls

Obese Day Surgery

Specific Considerations:

• Assessment: OSA severity, cardiac function, airway
• Anaesthesia: TIVA (dose by LBW), airway secure
• Positioning: Ramping, ensure ventilation adequate
• Analgesia: Multimodal (reduce opioids)
• Regional: Excellent if possible (blocks)
• Discharge: Extended observation if OSA

Indigenous Health Considerations

Aboriginal and Torres Strait Islander Patients

Access Issues:

• Geographic: Remote communities may not have day surgery facilities
• Travel: Extended time away from community
• Communication: Interpreter services if needed

Cultural Considerations:

• Escort: May be extended family member, not just "responsible adult"
• Communication: Clear written instructions (low health literacy in some communities)
• Follow-up: Ensure access to care post-discharge (remote area nurses, RFDS)
• Pain expression: May be stoic, ensure adequate analgesia provided

Māori Health Considerations

Cultural Safety:

• Whānau involvement: Family support for discharge
• Communication: Clear explanation of what to expect at home
• Discharge planning: Coordination with primary care
• Follow-up: Ensure access to healthcare post-discharge

ANZCA Final Exam Focus

SAQ Patterns

Common Questions:

• "What are the criteria for selecting patients for day surgery?"
• "Describe the anaesthetic technique for day surgery."
• "What discharge criteria are used in day surgery?"
• "How would you manage a patient with severe PONV in day surgery?"

Marking Scheme Priorities:

• Patient selection (medical, social, procedure criteria)
• Anaesthetic technique (TIVA preferred, short-acting drugs, regional, multimodal antiemetics)
• PONV prevention (dexamethasone, ondansetron, TIVA, avoid N₂O)
• Discharge criteria (Aldrete score, pain, nausea, escort, instructions)
• Post-discharge care (rescue analgesia, red flags, driving prohibition)

Viva Scenarios

Scenario 1: Conversion to Overnight Stay

• Severe PONV refractory to treatment
• Uncontrolled pain despite multimodal analgesia
• Social issues (no escort)

Scenario 2: Elderly Patient for Day Surgery

• Optimize for comorbidities
• TIVA preferred
• Clear discharge instructions for carer
• Extended observation

Scenario 3: Pediatric Tonsillectomy

• High PONV risk (blood in stomach)
• Multimodal antiemetic prophylaxis
• Ensure drinking before discharge
• Rescue antiemetic available

Key Points for Examination Success

1. Selection: ASA I-III, appropriate procedure, escort available, within travel distance of help
2. Technique: TIVA preferred (propofol), short-acting opioids (fentanyl, remifentanil), regional when possible
3. PONV: Multimodal prophylaxis mandatory (dexamethasone + ondansetron + TIVA), avoid N₂O
4. Discharge criteria: Aldrete >9, pain <4/10, no nausea, escort present, written instructions
5. Driving: 24-hour prohibition minimum
6. Oral intake: Not mandatory for all (fluids encouraged)
7. Voiding: Required after spinal, not required for GA alone
8. Pediatrics: >3-6 months typically, drinking important, sweetened midazolam premed
9. Elderly: TIVA reduces delirium, careful analgesia, ensure home support
10. Rescue plan: 24-hour contact, clear red flag instructions

References

1. ANZCA. PS04. Guidelines for the Management of Patients Fast-tracked from the Operating Theatre to the Ward. 2020.
2. ANZCA. PS21. Guidelines for Sedation and/or Analgesia for Diagnostic and Interventional Medical, Dental or Surgical Procedures. 2018.
3. White PF et al. The role of non-opioid analgesic techniques. Anesth Analg. 2005;101(5S):S5-S22.
4. Joshi GP. Ambulatory surgery: Current status and future perspective. F1000Res. 2020;9:F1000.
5. Apfel CC et al. A factorial trial of six interventions. N Engl J Med. 2004;350(24):2441-2451.
6. Chung F et al. Discharge criteria. Anesth Analg. 1995;80(5):1004-1010.
7. Joshi GP et al. Society for Ambulatory Anesthesia consensus statement. Anesth Analg. 2019;128(3):467-479.
8. ATSI Health. Access to health services in Aboriginal and Torres Strait Islander communities. Australian Institute of Health and Welfare; 2019.