Lower esophageal sphincter tone during reversal of neuromusclar blockade by atropine and neostigmine.

The effect on lower esophageal sphincter (LES) pressure of IV atropine and neostigmine, a drug combination routinely given to antagonize nondepolarizing neuromusclar blockade at the end of a general anesthetic, was studied in 22 patients undergoing cesarean section. Atropine 1.2 mg and neostigmine 2.5 mg IV decreased LES pressure insignificantly by a mean of 0.7 kPa (p less than 0.1). In contrast, atropine 1.2 mg and neostigmine 5 mg increased LES pressure by a mean of 1.4 kPa (p less than 0.001). The latter dosage of this drug combination, therefore, appears preferable in patients presenting for emergency surgery if the integrity of the lower esophageal sphincter is to be maintained during extubation and recovery from general anesthesia.