Use of the ON-Q pain management system is associated with decreased postoperative analgesic requirement: double blind randomized placebo pilot study

Narcotics are routinely used to decrease postoperative pain after laparotomy. But they are associated with unwarranted side effects. The aim of this study was to assess the effectiveness of local perfusion of bupivacaine in decreasing narcotic consumption after midline laparotomy.

We performed a prospective, randomized, double blind study involving patients who underwent a midline laparotomy with subsequent wound closure. Patients were randomized to receive a 72-hour continuous wound perfusion through the ON-Q pain management system (I Flow Corporation) of the local anesthetic bupivacaine (0.5%, study group) or 0.9% NaCl (control group). In addition, all patients received standardized intraoperative analgesia and postoperative morphine patient-controlled analgesia. Total postoperative analgesic requirement, pain control, recovery of bowel function, and complications were recorded.

Seventy patients were recruited: 35 in the study group (mean age, 55.7 years) and 35 in the control group (mean age, 58.8 years). There was no difference in overall postoperative pain scores. Patients in the study group reported earlier ambulation as compared with the control group. Mean (+/-SD) daily narcotic requirements were significantly less in the study group versus the control group (33.7+/-32 mg versus 60.1+/-62 mg, respectively; p=0.03). Patients in the study group made 50% fewer attempts to receive patient-controlled analgesia (p=0.011). But there was no significant difference in length of hospitalization or time to first bowel movement.

This preliminary pilot study revealed that the ON-Q pain management system after midline laparotomy, as part of a multimodal approach, is an effective approach to postoperative pain control.