Comparing preincisional with postincisional bupivacaine infiltration in the management of postoperative pain.

OBJECTIVE

To determine if preemptive local anesthesia yields better postoperative pain control than infiltration of local anesthetic at the time of wound closure.

DESIGN

Prospective, randomized trial.

SETTING

Private community teaching hospital.

PATIENTS

Two-hundred consecutive patients undergoing elective laparotomy were enrolled in the study between September 1993 and April 1995. Eighty-eight patients were excluded from the study for violation of protocol, leaving a total of 112 patients to be evaluated. Patients were divided into 2 groups: preincisional (n = 52) and postincisional (n = 60).

INTERVENTIONS

Patients in the preincisional group received 40 mL of 0.25% bupivacaine (Marcaine) 5 minutes before the incision; patients in the postincisional group received 40 mL of 0.25% bupivacaine immediately after approximation of the fascia and before closure of the skin.

MAIN OUTCOME MEASURES

The control of the long-term (3-day) postoperative pain in relationship to timing of local anesthetic given.

RESULTS

Study groups were comparable for age, weight, sex, operative time, and length of incision. No significant difference in the amount of morphine used or subjective evaluation of pain was noted between the preincisional and the postincisional groups.

CONCLUSIONS

Based on the theory of "dorsal horn hypersensitivity," several clinical trials have shown significant improvement in pain control with preincisional infiltration of local anesthetic. Our results indicate that pain was no better controlled with preincisional infiltration than with postincisional infiltration of bupivacaine, raising the question of the benefit of preemptive anesthesia at the local level in long-term postoperative care.