Functional recovery after neuromuscular blockade in mechanically ventilated critically ill patients

BackgroundAn estimated 24% to 70% of individuals have prolonged paralysis or severe weakness after receiving neuromuscular blocking agents (NMBAs) when therapy is terminated.ObjectivesThe purposes of this study were to (1) evaluate the relationship between recovery of neuromuscular transmission (NMT) and functional muscle activity after NMBA administration; (2) evaluate the relationship between delayed recovery of NMT or muscle activity and functional performance; and (3) determine the predictors of delayed recovery of NMT, muscle activity, and functional performance.MethodsThis was a multisite study using a prospective, nonexperimental, descriptive design with convenience sampling techniques. Instruments used included a five-point muscle score, Actigraph, and peripheral nerve stimulator.ResultsKey findings were as follows: (1) NMT returned promptly, whereas muscle activity remained severely depressed; (2) only two subjects (5%) recovered functional performance within 24 hours; (3) degree of muscle weakness immediately after neuromuscular blockade was associated with prolonged time to extubation and mobility; and (4) predictors of delayed recovery included cumulative dose of aminosteroid NMBAs, age, and renal function.ConclusionProlonged recovery of muscle activity and extreme weakness may occur despite brisk recovery of NMT after neuromuscular blockade.