Remifentanil PCA

• Labour analgesia when epidural contraindicated (coagulopathy, refusal)
• Difficult airway obstetric anaesthesia

μ-opioid agonism metabolised by non-specific plasma esterases → context-sensitive half-time ~3 min.

• Bolus 40 μg lockout 2 min (protocol-dependent)
• Continuous SpO₂ + midwife 1:1
• Have naloxone + O₂ ready

PCA bolus

20–40 μg with 2 min lockout

Elective LSCS (rare)

0.5–1 μg/kg over 30 s at induction

• AbsoluteInadequate 1:1 supervision
• AbsoluteUntreated hypoxia
• CautionMorbid obesity, OSA

• Apnoea, desaturation (must monitor SpO₂ continuously)
• Bradycardia, hypotension
• Nausea, itching
• Muscle rigidity at high dose

• • Rapidly cleared — least neonatal depression of IV opioids
• • Still can cause transient neonatal respiratory depression

• Other CNS depressants

  Avoid

  Additive respiratory depression

• 💡 Requires trust-wide PCA protocol + training
• 💡 Convert to epidural if labour long or PCA inadequate