The criteria, in order
Fully reversed with a nerve stimulator train-of-four ratio above 0.9, awake and obeying commands, adequate tidal volumes and respiratory rate, protective reflexes returned, normothermic, haemodynamically stable, and the surgery genuinely finished. Any one of these missing is a reason to wait.
Residual paralysis is the hidden problem
A patient can lift their head, grip your hand and still have a train-of-four ratio well below 0.9, at which point pharyngeal coordination is impaired and aspiration risk is real. Clinical tests are not sensitive enough; quantitative monitoring is how residual block is excluded.
Awake or deep
Extubating awake protects the airway but risks coughing, hypertension and bleeding. Extubating deep avoids the cough but leaves an unprotected airway. Awake is the default; deep extubation belongs to specific situations and to people practised in it.
Laryngospasm
Complete or partial glottic closure, most often during light emergence with a stimulus in the airway. Remove the stimulus, apply continuous positive pressure with one hundred percent oxygen, and press firmly at the laryngospasm notch behind the earlobe. If that fails, deepen with propofol, and if it still fails, a small dose of suxamethonium.