“…137 However, discrepancies exist between an assessment of the T4/T I ratio, using either visual or tactile estimation, and the degree of neuromuscular block. 138 In the presence of a residual neuromuscular block, the patient with a tracheal tube in place may be capable of eliciting an adequate tidal volume (10-12 ml. kg -1) and of generating a negative inspiratory pressure > 30 cm H20 yet, following extubation, the patient is incapable of maintaining a patentairwaydueto weakness of the upper airway muscles.…”