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Long-Acting Local Anaesthetic (Amide) Pregnancy: Used at caesarean section (spinal bupivacaine heavy 0.5% is standard); avoid inadvertent IV

Bupivacaine

Brand names: Marcain, Marcain Heavy (spinal)

Adult dose

Dose: Spinal: 2.5-4 mL of 0.5% hyperbaric (heavy). Epidural: 10-20 mL of 0.25-0.5%. Nerve block: 0.25-0.5%, up to max safe dose
Route: Intrathecal (spinal) / Epidural / Peripheral nerve block
Frequency: Single injection (spinal); top-up boluses or infusion (epidural)
Max: 2 mg/kg (plain); 2.5 mg/kg (with adrenaline) — systemic limit
Most cardiotoxic of the long-acting local anaesthetics — has narrow safety margin; injection must be slow with frequent aspiration to detect intravascular placement

Paediatric dose

Dose: 1-2 mg/kg (caudal/epidural); 0.5 mg/kg (spinal in infants) mg/kg
Route: Epidural / Caudal / Spinal
Frequency: Single or continuous
Max: 2 mg/kg
Caudal: 0.5-2.5 mg/kg (0.25% solution). Seek specialist paediatric anaesthesia input

Dose adjustments

Renal

No dose adjustment for regional anaesthesia doses

Hepatic

Use with caution — metabolised by liver; accumulation in hepatic impairment with infusions

Paediatric weight-based calculator

Caudal: 0.5-2.5 mg/kg (0.25% solution). Seek specialist paediatric anaesthesia input

Clinical pearls

  • LAST treatment: 20% intralipid emulsion — 1.5 mL/kg IV bolus, then 0.25 mL/kg/min infusion; maximum 12 mL/kg total; bupivacaine cardiotoxicity is the classical indication for lipid rescue
  • Most cardiotoxic long-acting LA: bupivacaine binds Na+ channels with high affinity in 'fast-in, slow-out' pattern — resuscitation is prolonged; cardiopulmonary bypass may be required
  • Hyperbaric (heavy) bupivacaine for spinal: contains glucose; density higher than CSF — position patient to direct block; isobaric for sitting position procedures
  • Maximum dose calculations must account for concentration, volume, and site of injection — vascular sites (intercostal) absorb faster; less vascular (subcutaneous) absorb slower
  • AAGBI Lipid Rescue guidelines: 20% intralipid must be immediately available wherever local anaesthetics are used for regional anaesthesia

Contraindications

  • IV administration (except cardiac arrest from LA toxicity per ACLS)
  • Inflamed or infected tissue injection site
  • LAST (local anaesthetic systemic toxicity) already present

Side effects

  • LAST (local anaesthetic systemic toxicity) — CNS: circumoral tingling, tinnitus, seizures; Cardiac: ventricular arrhythmias, cardiac arrest
  • High spinal/epidural (total spinal)
  • Hypotension (sympathetic block — spinal/epidural)
  • Urinary retention

Interactions

  • Other local anaesthetics (additive toxicity)
  • Antiarrhythmics (additive cardiac effects)
  • Adrenaline (prolongs duration, reduces systemic absorption)

Monitoring

  • Cardiovascular monitoring during and after injection
  • Neurological symptoms (LAST)
  • Block level (spinal/epidural)
  • Urinary output

Reference: BNFc; BNF 90; AAGBI LAST Guidelines 2023; Marcain SPC; NAP3 Report (Regional Anaesthesia). Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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