Fig. 1.

Mechanisms of residual paralysis induced postoperative respiratory failure. A small level of residual paralysis that cannot be detected without quantitative monitoring of the train-of-four (TOF) response impairs several important facets of respiratory function. The main mechanisms of respiratory failure induced by minimal, residual neuromuscular blockade (TOF: 0.5–0.9) are impairments of hypoxic ventilatory response, and respiratory muscle function. In addition, the coordination between breathing and swallowing is impaired, leading to the inability to protect the airway during swallowing. Consequently, paralysis increases the vulnerability to hypoxia, symptomatic aspiration, pulmonary edema, and reintubation