To assess the
analgesic efficacy of patient-controlled
bupivacaine wound instillation, 50 patients undergoing major intraabdominal surgery were enrolled into this prospective, placebo-controlled, double-blinded study. In all cases, a standard
general anesthetic was administered. On completion of surgery, two multihole 20-gauge epidural
catheters were tunneled through the proximal and distal apices of the
surgical wound and placed above the fascia such that the
tips were at the margin of the first and second thirds of the
surgical wound, respectively. Postoperatively, a
patient-controlled analgesia (PCA) device was connected to the instillation system. Either
bupivacaine 0.25% (
Bupivacaine Group) or an equal volume of sterile water (Control Group) was administered. The PCA device was programmed to deliver 9.0 mL with a 60-min lockout interval and no basal infusion. During the first six postoperative hours, a coinvestigator administered "rescue"
morphine (2 mg IV). Thereafter,
meperidine 1 mg/kg IM was administered on patient request for additional
analgesia. Instillation attempts and actual number of
injections were similar between the groups. The mean number of pump infusions and the mean "rescue"
opioid requirements during the 24-h study period were similar between the groups. The total "rescue"
morphine administered during the first six postoperative hours was 16 +/- 17 mg vs 18 +/- 14 mg for the
Bupivacaine and Control Groups, respectively. The total
meperidine administered during this period was 1.6 +/- 1.4 mg/kg and 2 +/- 1.2 mg/kg for the
Bupivacaine and Control Groups, respectively. Preoperatively, hourly for the first six postoperative hours, and on removal of the instillation
catheter, patient-generated visual analog scales for
pain were similar at rest, on coughing, and after leg raise. In conclusion,
bupivacaine wound instillation via an electronic PCA device and a double-
catheter system does not decrease postoperative
opioid requirements after surgery performed through a midline incision.
IMPLICATIONS: