Dose and administration

1. 100 micrograms/kg IV push, as needed for paralysis.
2. Usual dosing interval is 1-2 hours. Adjust dose as needed based on duration of paralysis.

Indications

1. Skeletal muscle relaxation or paralysis in infants requiring mechanical ventilation.
2. Proposed desirable effects are improved oxygenation/ventilation, reduced barotrauma and reduced cerebral blood flow fluctuations.

Contraindications and Precautions

1. Known hypersensitivity to bromide.
2. Non-intubated infants.
3. Infants in whom tachycardia is undesirable.
4. Caution in infants with fluid and electrolyte imbalance.
5. Caution in infants with pulmonary, hepatic, renal disease.

Clinical Pharmacology

Pancuronium is a non-depolarising muscle relaxant that competitively antagonises autonomic cholinergic receptors and also causes sympathetic stimulation. Cardiovascular effects (increased heart rate and blood pressure) are non-existent or mild. Histamine release is absent or weak. The drug is partially hydroxylated by the liver, 40% is excreted unchanged in the urine.

The dose required for neuromuscular blockage (95% depression of twitch height) is extremely variable: the daily dose ranges between 100 and 1100 mcg/kg/day. The onset of action is 1-2 minutes. Duration of neuromuscular blockade varies with dose and age. Acidosis, hypothermia, neuromuscular disease, hepatic disease, renal failure, cardiovascular disease, aminoglycosides, hypermagnesaemia, hypocalcaemia, and immaturity potentiate duration of neuromuscular blockage. Alkalosis, hypercalcaemia and adrenaline antagonise duration of neuromuscular blockage. Infants appear to recover fully from the effect of pancuronium after 20 hours.

The effects of pancuronium are reversed by neostigmine (60 micrograms/kg) and atropine (20 micrograms/kg).

Possible Adverse Effects

1. Hypoxaemia may occur because of inadequate mechanical ventilation and deterioration in pulmonary mechanics.
2. Tachycardia and blood pressure changes (both hypotension and hypertension) occur frequently.
3. Increased salivation.
4. Oedema secondary to third-spacing of fluids.
5. Ventricular extrasystole.
6. Muscle wasting and hypotonia associated with prolonged use.

Special Considerations

1. The duration of neuromuscular blockage is influenced by acid base status, electrolyte disturbances, disease states, and a variety of drugs. The duration of effect may be either shortened or lengthened.
2. The management of pancuronium overdose includes supportive mechanical ventilation and reversal with neostigmine and atropine.