Effects of block analgesia on attenuating intraoperative stress responses during oral surgery

Surgical intervention affects cardiorespiratory function and deteriorates the homeostatic mechanisms. The aim of this study was to evaluate the effect of block analgesia, which may minimize the intraoperative stress responses during oral surgery. In addition, we evaluated whether block analgesia could lessen the anesthetic requirements. Twenty-eight operative patients were randomly allocated to one of four groups: group 1, 1.3MAC without block analgesia; group 2, 1.6MAC without block analgesia; group 3, 1.0MAC with block analgesia; and group 4, 1.3MAC with block analgesia. Systolic blood pressure (SBP), heart rate (HR), and plasma norepinephrine levels (NE) were measured and compared. Results showed that the increases in SBP, HR, and NE in groups 1 and 2 were greater than those in groups 3 and 4. SBP elevation in group 1 was the greatest among all groups. These results suggest that block analgesia appears to be effective for preventing hyperreactivity of the sympathetic nervous and endocrine systems. In conclusion, general anesthesia combined with block analgesia assures safer anesthesia for patients with cardiovascular diseases or elderly patients who require cardiovascular stability during surgery.