Obese Patients

Reports are conflicting concerning the effect of obesity on the pharmacodynamics of nondepolarizing neuromuscular blockade.^{[698] [699] [700]} Although the duration of action of pancuronium is unaffected by patient weight,^[700] obese patients recover more slowly from doxacurium-,^[701] vecuronium-,^[702] or rocuronium-induced^[703] neuromuscular blockade. These findings imply that elimination of these drugs is decreased. Recovery from atracurium-induced neuromuscular blockade is not affected by obesity,^[702] which is most likely secondary to its lack of dependence on end-organ function for elimination.

Neuromuscular blockers should be dosed in obese patients on the basis of about 20% more than lean body mass rather than on actual body weight^[704] to ensure that these patients are not receiving relative overdoses.