Failure of lower esophageal contractility to predict patient movement in children anesthetized with halothane and nitrous oxide.

The clinical usefulness of monitoring the frequency of spontaneous lower esophageal contractions (SLEC) to assess the depth of anesthesia was evaluated in 38 children. The hypothesis that SLEC can predict movement in response to skin incision during nitrous oxide and halothane anesthesia was tested. Although movement in response to skin incision was correlated with an increase in heart rate, blood pressure, and an increased SLEC frequency, there was no correlation between the SLEC prior to skin incision and movement in response to this stimulus. Moreover, cardiovascular responses preceded the detection of SLEC changes. The relationship between changes in SLEC activity and times to awakening during emergence from anesthesia was also examined. During emergence from anesthesia there was an increase in SLEC, but the time to awakening could not be predicted from the SLEC. Cardiovascular changes again preceded SLEC changes during emergence. Monitoring of the lower esophageal contractility rate would appear to be of limited usefulness in evaluating the depth of anesthesia in unparalyzed children during nitrous oxide and halothane anesthesia.