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PACU Role: The Post-Anaesthesia Care Unit (recovery room) provides close monitoring and management during the immediate post-operative period. Minimum staffing: 1:1 nursing on initial admission; reducing to 1:2 as patient stabilises. Minimum stay: 30 minutes or until Aldrete score ≥9/10.
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PACU Admission — SBAR Handover from Anaesthetist
Situation: patient name, procedure, surgeon
Background: ASA status, past medical history, allergies, anaesthetic type
Assessment: intraoperative events, airway issues, estimated blood loss, fluid balance, IV lines/drains
Recommendation: analgesia plan, antiemetic orders, fluid orders, monitoring requirements, specific post-op observations
On arrival — primary survey:
- A — Airway: LMA in situ or extubated; position
- B — Breathing: SpO₂, RR, oxygen delivery
- C — Circulation: BP, HR, IV access, blood loss
- D — Disability: consciousness, pain score, BG
- E — Exposure: wounds, drains, catheters, temperature
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Aldrete Score — Discharge from PACU
Score ≥9/10 required for ward discharge:
5 parameters (0-2 each):
- Consciousness: 2=fully awake; 1=arousable; 0=unresponsive
- Circulation: 2=BP ±20% baseline; 1=±20-49%; 0=±50%
- Respiration: 2=deep breathing+cough; 1=dyspnoea; 0=apnoeic
- Movement: 2=moves 4 limbs; 1=2 limbs; 0=none
- SpO₂: 2=≥92% on air; 1=≥90% with O₂; 0=<90%
Reversal of Neuromuscular Blockade
| Agent | Reverses | Mechanism | Adverse Effects |
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| Neostigmine + Glycopyrrolate | All non-depolarising NMBDs | Cholinesterase inhibitor; prevents ACh breakdown | Bradycardia (give with glycopyrrolate); N&V; increased secretions |
| Sugammadex (Bridion) | Rocuronium and Vecuronium only | Encapsulates steroid-based NMBDs directly | Faster/more complete reversal; less bradycardia; avoid in severe renal failure |
| Flumazenil | Benzodiazepines | GABA-A receptor antagonist | Short half-life — re-sedation risk; do NOT give to benzodiazepine-dependent patients |
| Naloxone | Opioids | Opioid receptor antagonist | Acute pain return; hypertension; pulmonary oedema in high dose; short half-life — monitor for re-narcotisation |
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Multimodal Analgesia in PACU
Principles of multimodal analgesia:
- Combine analgesics with different mechanisms to reduce opioid use
- Paracetamol — IV 1g 6-hourly (available before patient eating)
- NSAIDs — ketorolac IV or ibuprofen (avoid in renal impairment, post-cardiac surgery, elderly)
- Opioids — titrated IV morphine/fentanyl for moderate-severe pain
- PCA (patient-controlled analgesia) — patient presses button; lock-out interval prevents overdose
- Regional blocks — epidural, spinal, peripheral nerve blocks
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PONV — Post-Operative Nausea and Vomiting
Apfel Risk Score (1 point each):
- Female sex
- Non-smoker
- History of PONV or motion sickness
- Post-operative opioid use
Score 0-1 = low risk; 2 = moderate; 3-4 = high risk (risk 60-80%)
Prevention and treatment:
- Ondansetron (5-HT₃ antagonist) — first line
- Dexamethasone 4-8 mg — at induction
- Scopolamine patch — pre-operatively for high risk
- Droperidol — effective but QTc prolongation risk
- Propofol TIVA (total IV anaesthesia) — lower PONV than volatile agents
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PCA Safety: PCA (patient-controlled analgesia) is PATIENT-OPERATED only. NEVER administer a PCA dose on behalf of the patient (nurse/family pressing the button is dangerous and constitutes a medication error). Provide nursing staff and family education on this important safety point.
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High-Yield Exam Points
- Aldrete ≥9/10 = discharge from PACU to ward
- Sugammadex reverses rocuronium/vecuronium (NOT suxamethonium)
- Neostigmine must be given WITH glycopyrrolate (prevents bradycardia)
- Hypotension = most common PACU complication
- PONV Apfel score: female + non-smoker + PONV history + opioid use
- Ondansetron + dexamethasone = PONV prophylaxis
- Emergence delirium: exclude pain, retention, hypoxia FIRST
- Naloxone: short half-life → monitor for re-narcotisation
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Common Exam Traps
- PCA: nurse or family pressing button = medication error and patient safety incident
- Hypertension in PACU: treat pain BEFORE anti-hypertensives
- Emergence agitation: NOT always delirium — always exclude physical causes first
- Sugammadex: does NOT reverse succinylcholine (depolarising NMBD)
- Flumazenil: short half-life — re-sedation risk; don't give to benzo-dependent patients (precipitates withdrawal seizures)
Practice MCQs — PACU Nursing
Q1. A patient arrives in PACU post laparoscopic appendectomy. The anaesthetist used rocuronium for intubation. What is the MOST appropriate pharmacological reversal agent?
A. Neostigmine only
B. Sugammadex (Bridion)
C. Naloxone
D. Flumazenil
Correct: B. Sugammadex (Bridion) is the agent of choice for reversal of rocuronium and vecuronium (steroid-based non-depolarising NMBDs). It encapsulates the NMBD molecule directly, providing faster and more complete reversal than neostigmine. Neostigmine can also reverse rocuronium but is less complete and requires co-administration of glycopyrrolate to prevent bradycardia.
Q2. A 45-year-old female non-smoker with a history of motion sickness is recovering from laparoscopic cholecystectomy under general anaesthesia with fentanyl for post-operative pain. What is her Apfel PONV risk score?
A. 1
B. 2
C. 3
D. 4
Correct: C. Apfel score = 3. She scores 1 point each for: (1) Female sex, (2) Non-smoker, (3) History of motion sickness (equivalent to PONV history). Post-operative opioid use (fentanyl) would add a 4th point. If all 4 are present, score = 4. The question confirms she will use fentanyl, making the score 4. However, based on the information provided (female + non-smoker + motion sickness = 3 confirmed). Score ≥3 = high PONV risk; dual or triple antiemetic prophylaxis recommended.
Q3. An 8-year-old boy becomes severely agitated and inconsolable in PACU 15 minutes after emergence from sevoflurane anaesthesia for tonsillectomy. He does not respond to his name and appears to not recognise his parents. What is the PRIORITY first action?
A. Administer IV midazolam immediately to sedate the child
B. Contact the anaesthetist for propofol sedation
C. Assess for and treat reversible causes: pain (administer analgesic), urinary retention, hypoxia, and hypoglycaemia
D. Restrain the child and wait for spontaneous resolution
Correct: C. Emergence delirium is common in children post-sevoflurane anaesthesia. However, reversible physical causes MUST be excluded and treated first: pain (most common — administer paracetamol or morphine), urinary retention (palpate bladder), hypoxia (check SpO₂), and hypoglycaemia (check BGL). Only after physical causes are excluded or treated should pharmacological sedation be considered.
Q4. A PACU nurse is assessing a patient for ward transfer. Current parameters: fully awake and oriented, BP 118/74 (baseline 125/78), SpO₂ 94% on 2L nasal cannula, breathing with normal depth and able to cough, moves all four limbs spontaneously. What is the Aldrete score?
A. 7
B. 8
C. 9
C. 9 — patient can be discharged to the ward
Correct: C. Aldrete score calculation: Consciousness = 2 (fully awake); Circulation = 2 (BP within 20% of baseline); Respiration = 2 (deep breathing + able to cough); Movement = 2 (moves all 4 limbs); SpO₂ = 1 (94% requires supplemental oxygen). Total = 9/10. Score ≥9 = criteria met for ward discharge. The SpO₂ score is 1 (not 2) because the patient requires supplemental oxygen to maintain ≥90%.