The effect of single-dose and continuous skeletal muscle paralysis on respiratory system compliance in paediatric intensive care patients.

Objective: To investigate the effect of single dose and continuous skeletal muscle paralysis on respiratory system compliance in 53 paediatric intensive care patients.

Design: Prospective clinical study.

Setting: Multidisciplinary paediatric intensive care unit.

Patients: Twenty-three children ventilated for acute pulmonary pathology, and 30 ventilated for isolated intracranial pathology, who initially had normal lungs.

Interventions: The 23 patients with acute pulmonary pathology received a single dose of muscle relaxant to facilitate diagnostic procedures. Fifteen patients with isolated intracranial pathology received continuous skeletal muscle paralysis for longer than 24 h, and the other 15 received no paralysis.

Measurements And Results: Respiratory system compliance deteriorated by 14% from 0.519 +/- 0.2 to 0.445 +/- 0.18 ml cmH2O-1 kg-1 (p < 0.001) following a single dose of muscle relaxant in the 23 patients with acute pulmonary pathology. In the 15 with isolated intracranial pathology who received continuous skeletal muscle paralysis there was a progressive deterioration in compliance, which reached 50% of the initial compliance by day 4 of paralysis (p < 0.001) and improved back to normal following discontinuation of paralysis. There were no changes in compliance in the 15 patients with isolated intracranial pathology who were ventilated but not paralysed. The paralysed patients required mechanical ventilation longer than the non-paralysed patients (p < 0.001), and 26% of these patients developed nosocomial pneumonia (p = 0.03), a complication that was not seen in the non-paralysed patients.

Conclusions: Skeletal muscle paralysis results in immediate and progressive deterioration of respiratory system compliance and increased incidence of nosocomial pneumonia. The benefits of paralysis should be balanced against the risks of deteriorating pulmonary function.