Neurophysiological study of critical illness polyneuropathy and myopathy in mechanically ventilated children; additional aspects in paediatric critical illness comorbidities

Abstract

Background and purpose: Critical illness polyneuropathy and myopathy (CIP/CIM) is being increasingly recognized as a significant clinical problem in critically ill children especially if they have spent long periods in the intensive care unit. So the aim was to determine the frequency of CIP/CIM amongst mechanically ventilated children and to analyse the associated risk factors and drawbacks frequently encountered in this cohort.

Methods: The study included 105 patients admitted to the paediatric intensive care unit who underwent mechanical ventilation for ≥7 days. These patients were screened daily for awakening. Patients with severe muscle weakness on day 7 post-awakening underwent nerve conduction studies and electromyography. Accordingly, the patients were classified as CIP/CIM patients if they had abnormal neurophysiology studies or control patients if normal neurophysiology studies were obtained. Their clinical and laboratory profiles had been recorded as well.

Results: Overall, of 105 patients who achieved satisfactory awakening, 34 patients (32.4%) developed CIP/CIM mostly of the axonal polyneuropathy pattern (27.6%) whilst 71 control patients (67.6%) showed normal electrophysiological studies. The mean duration of mechanical ventilation was significantly longer in patients with CIP/CIM compared to control patients (P = 0.001). The study also revealed that 62.1% of our CIP/CIM patients failed weaning trials and finally died. CIP/CIM was significantly associated with decreased platelets, elevated liver enzymes and prolonged prothrombin time. Acidosis, low serum calcium and albumin levels and higher blood glucose were also found to be more significant in CIP/CIM patients compared to control patients.

Conclusion: Critically ill children frequently develop CIP/CIM, mostly of axonal polyneuropathy pattern, which compromises rehabilitation and recovery and is associated with a number of comorbidities.

Keywords: critical illness; electromyography; mechanical ventilation; myopathy; nerve conduction; polyneuropathy.