Effect of Enflurane, Isoflurane, and Halothane on Pacing Stimulation Thresholds in Man

Volatile anesthetic agents are often used in patients who require temporary epicardial pacing after cardiopulmonary bypass (CPB). However, the effect of anesthetic agents on energy stimulation thresholds is unknown. After CPB, 24 patients under diazepam-narcotic-pancuronium anesthesia ventilated with an FIO2 = 1.0 received equipotent concentrations of either enflurane, isoflurane, or halothane. Using temporary epicardial electrodes, energy stimulation thresholds were calculated using the data derived from a pacing systems analyzer. Volatile anesthetics do not change energy stimulation thresholds from those already present under diazepam-narcotic-pancuronium anesthesia.