Functional recovery after neuromuscular blockade in mechanically ventilated critically ill patients.

Background: An estimated 24% to 70% of individuals have prolonged paralysis or severe weakness after receiving neuromuscular blocking agents (NMBAs) when therapy is terminated.
Objectives: The 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.
Methods: This 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.
Results: Key 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.
Conclusion: Prolonged recovery of muscle activity and extreme weakness may occur despite brisk recovery of NMT after neuromuscular blockade.