Prolonged paralysis after neuromuscular junction blockade: case reports and electrodiagnostic findings.

Previous reports have described prolonged paralysis after treatment with neuromuscular junction (NMJ) blocking agents in critically ill patients. The purpose of this study was to describe the clinical and electrodiagnostic findings in 12 such patients. All patients developed prolonged and often profound weakness with no sensory loss after discontinuation of NMJ blockers. Nerve conduction studies generally showed decreased motor evoked response amplitudes with normal conduction velocities and normal sensory studies. Repetitive nerve stimulation demonstrated no decrement or increment in most patients, with a decrement to 3 Hz stimulation in one patient. Needle examination showed frequent fibrillation potentials and normal or low amplitude, short duration, polyphasic motor units. Physicians prescribing NMJ blockers in critically ill patients should be made aware of this potential complication and of the other agents (ie, corticosteroids) that may exacerbate the problem.