[Prolonged muscle weakness associated with the administration of non-depolarizing neuromuscular blocking agents in...

Generalized muscle weakness is a common disorder in patients undergoing mechanical ventilation. The cause is unknown but is attributed to the administration of non-depolarizing neuromuscular blocking and other drugs, mainly steroids, or to the presence of sepsis or multiorgan failure. Specific clinical pictures (polyneuropathy, myopathy and prolonged muscle weakness) develop in function of the underlying cause, although etiological factors may sometimes interact. Differential diagnosis is carried out with the aid of electromyography and pathology of the peripheral muscle. Costs are high and prognosis is uncertain. Completeness of neuromuscular blockade must be monitored in these patients to guide the administration of drugs, to avoid overdoses, to maintain muscle activity and to detect a chain of reactions among concomitant medications or pathophysiologic changes.