Volatile Inhalational Anaesthetic
Pregnancy: Caution — avoid unnecessary exposure in early pregnancy; safe for caesarean section at appropriate doses
Sevoflurane
Brand names: Ultane, Sevorane
Adult dose
Dose: Induction: 4–8%; Maintenance: 0.5–3% (MAC 2.05%)
Route: Inhalational
Frequency: Continuous during anaesthesia
Max: MAC adjusted for age and co-induction agents
Gold-standard volatile for induction and maintenance. Non-pungent — preferred for gas induction. MAC decreases with age (~1.6% at 80 years). Minimum fresh gas flow 2 L/min to limit compound A formation.
Paediatric dose
Route: Inhalational
Frequency: Continuous
Max: 8% for induction
Preferred volatile for paediatric gas induction — non-pungent and rapid onset. MAC higher in children: ~2.5% at 1–6 months.
Dose adjustments
Renal
Minimum fresh gas flow ≥2 L/min to limit compound A — nephrotoxic at high concentrations in low-flow circuits.
Hepatic
Avoid if previous volatile anaesthetic-associated hepatitis.
Clinical pearls
- Malignant hyperthermia antidote: DANTROLENE 2.5 mg/kg IV bolus — repeat every 5–10 min up to 10 mg/kg; stop all volatile triggers immediately; switch to TIVA; call MH hotline
- RCoA sustainability policy: sevoflurane preferred over desflurane — desflurane has ~2,500× GWP of CO₂
- Fastest gas induction of all volatiles due to non-pungent properties — ideal for needle-phobic or paediatric patients
Contraindications
- Known or suspected malignant hyperthermia (MH) susceptibility
- Previous volatile anaesthetic-associated hepatitis
Side effects
- Malignant hyperthermia (rare but life-threatening)
- Respiratory depression
- Dose-dependent hypotension
- Compound A nephrotoxicity (low-flow circuits)
- QT prolongation (rare)
Interactions
- Neuromuscular blocking agents (potentiate block)
- QT-prolonging drugs (additive)
- Beta-blockers (additive bradycardia)
Monitoring
- End-tidal agent concentration (agent analyser mandatory)
- SpO2, ETCO2, BP, HR
- Temperature (MH surveillance)
Reference: BNFc; BNF 90; RCoA GPAS 2023; AAGBI Malignant Hyperthermia Guidelines 2020. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators