Hemodynamic Effects of General Anesthesia during Thoracic Epidural Block

Choi, Kyu Tack; Park, Jung Won; Lim, Tae Ha; Lee, Dong Myung; Suh, Byung Te

Abstract

BACKGROUND: It has been a standard practice in many institutions to combine light general anesthesia with epidural block for abdominal and pelvic surgery. We attempted to prove the effectiveness of prehydration and to find an suitable epidural local anesthetic dose in terms of hemodynamic stability for upper abdominal surgery.
METHODS
For preliminary studies, 11 patients scheduled for elective upper abdominal surgery had received general anesthesia immediately after epidural anesthesia. After epidural injection of 10~16 mL of 2% plain lidocaine into the T9~10 intervertebral space, the changes in blood pressure were observed. Thirty-two patients scheduled for elective upper abdominal surgery were divided into two groups. In group A (study group), after prehydration with Hartmann solution (10 mL/kg), 5~7 mL of 2% plain lidocaine was injected into T8~9 or T9~10 intervertebral space and general anesthesia was then induced. Group B (control group) received general anesthesia only.
RESULTS
There were no significant differences in hemodynamics between the epidural with general anesthesia and the control group except SVR (systemic vascular resistance). SVR in group A increased in contrast to the group B in which it remained unchanged.
CONCLUSIONS
The combined epidural and general anesthesia, using prehydration and 0.5~1 mL/segment of 2% plain lidocaine at the T8~9 or T9~10 intervertebral space was safe without significant hemodynamic changes.