Neuromuscular complications of sepsis

Sepsis and multiple organ failure are major problems in medical and surgical intensive care units. Critical illness polyneuropathy occurs in 70% of these patients. Difficulty in weaning from the ventilator is an early sign. Electrophysiological studies are necessary to establish the diagnosis; these studies show an axonal degeneration of peripheral nerve fibres. Recovery occurs in weeks or months, depending upon severity. Muscle biopsy reveals denervation atrophy. Sepsis itself does not induce a neuromuscular transmission defect, but neuromuscular blocking agents may increase the severity of critical illness polyneuropathy. If steroids are used in addition to neuromuscular blocking agents, a severe myopathy may result. Other effects on muscle are cachectic myopathy and panfascicular muscle fibre necrosis. A variety of combinations of these conditions may affect the same patient. Only well-designed prospective studies will determine the true effect of these medications on the neuromuscular system in septic patients.