A 25 year old overweight female was given fentanyl-pancuronium anaesthesia for surgery. After surgery and extubation she was observed to have limited movement of the upper body and chest wall in the recovery room. She was conscious and alert but voluntary respiratory effort has limited. Her blood pressure and heart rate were normal. The likely diagnosis is –

Residual neuromuscular paralysis after extubation is a common complication after administration of neuromuscular blocking agents (especially long acting agents like pancuronium). The presence of limited movements of upper body (residual paralysis) along with reduced voluntary respiratory effort (residual weakness) after extubation in patients who have received long acting neuromuscular blockers (like pancuronium) suggest a diagnosis of incomplete reversal of the muscle relaxation effect of the anesthetic drug.