Cardiovascular criteria for epidural test dosing in sevoflurane- and halothane-anesthetized children.

Abstract

This study was designed to determine the detectability of a simulated IV test dose in children during administration of general anesthesia by using heart rate (HR), systolic blood pressure (SBP), and T wave criterion. Forty-two children (0.5-8 yr old) received an IV injection containing epinephrine 0.5 microg/kg and another IV injection containing saline during either halothane or sevoflurane anesthesia administration at 1.0 minimum alveolar concentration in nitrous oxide. A positive test response was defined as a change in T wave amplitude >/=25%, SBP increase >/=15 mm Hg, and HR increase >/=10 bpm. By using the T wave, SBP, and HR criteria, a positive response rate to epinephrine was 100%, 95%, and 71%, respectively, during sevoflurane, and 90%, 71%, and 71%, respectively, during halothane anesthesia administration. These data suggest that the T wave criterion is superior to conventional hemodynamic criteria, and that sevoflurane attenuates T wave and SBP responses less than halothane; however, chronotropic responses are similar to halothane. We found a greater reliability of the T wave criterion over conventional hemodynamic criteria for detecting intravascular injection of a simulated epidural test dose. Sevoflurane may increase the likelihood of recognition of an accidental intravascular injection of epinephrine-containing solutions in clinical practice compared with halothane.