Neuromuscular Blockade in Intensive Care

Neuromuscular blockade is given by infusion to a few ventilated patients, mainly those with early severe acute respiratory distress syndrome (PaO2/FiO2 under 150), severe ventilator dyssynchrony, raised intracranial pressure, or shivering during temperature control. It is only given with deep sedation and analgesia, because a paralysed patient cannot show awareness.

Duration. Limit the infusion to the shortest effective time, usually 24 to 48 hours, and reassess daily. Prolonged use, and use with high-dose corticosteroids, raise the risk of ICU-acquired weakness.

Elimination. Cisatracurium is broken down by Hofmann elimination and is independent of kidney and liver function. Rocuronium and vecuronium depend on the liver and kidney and accumulate.

Preferred. Cisatracurium, especially in kidney or liver failure.

Alternatives. Rocuronium infusion. Vecuronium is less used because it accumulates.

Not for infusion. Suxamethonium.

Special groups.

• Children: weight-based dosing and sedation management by a specialist.

• Pregnancy: used with specialist support when oxygenation requires it.

• Hepatic and kidney failure: cisatracurium.

• Myasthenia, hypermagnesaemia, aminoglycosides, and hypokalaemia: prolong or increase effect.

• East Africa: if train-of-four monitoring is not available, avoid infusions and use intermittent boluses directed by clinical need.

• Cisatracurium: bolus 0.15 to 0.2 mg/kg intravenously, then infusion 1 to 3 micrograms/kg/min (range 0.5 to 10).

• Rocuronium: bolus 0.6 to 1.2 mg/kg, then infusion 0.3 to 0.6 mg/kg/h.

• Vecuronium: bolus 0.08 to 0.1 mg/kg, then infusion 0.8 to 1.7 micrograms/kg/min.

• Reversal: sugammadex 2 to 4 mg/kg for rocuronium or vecuronium, or neostigmine 50 micrograms/kg (maximum 5 mg) with glycopyrronium 10 micrograms/kg.

Monitoring. Train-of-four at least every 4 hours, aiming for a count of 1 to 2 of 4 twitches. Check sedation depth with an EEG-derived index where available, give eye care and pressure care, use thromboprophylaxis and keep glucose controlled.

Stop rules. Stop for improved oxygenation and compliance after 24 to 48 hours, for adverse effects, or when the indication ends. Let the train-of-four return to 4 of 4 before assessment.

Referral and escalation. For paralysis lasting much longer than expected after stopping, measure creatine kinase, electrolytes and magnesium, and seek neurology review for critical illness neuromuscular disease.

Common errors. Giving blockade without adequate sedation, omitting train-of-four monitoring, using steroid with prolonged blockade, and failing to protect the eyes.