Continuous wound infiltration system for postoperative pain management in gynecologic oncology patients.

PURPOSE: Major open surgery for gynecologic cancer usually involves a long midline skin incision and induces severe postoperative surgical site pain (POSP) that may not be effectively controlled with the conventional management. We investigated whether combining a continuous wound infiltration system (CWIS, ON-Q PainBuster®) and intravenous patient-controlled analgesia (IV PCA) effectively decreases POSP, compared with IV PCA alone, in gynecologic oncology patients. METHODS: This retrospective study included 62 Korean patients who received a long midline skin incision during gynecologic cancer surgery. The combined therapy group (n = 31), which received CWIS (0.5% ropivacaine infused over 72 h) and IV PCA (fentanyl citrate), and the IV PCA only group (n = 31) were determined using 1:1 matching. POSP was assessed using resting numeric rating scale (NRS) scores measured for 96 h after surgery, which were analyzed using a linear mixed model. RESULTS: The slopes of the predicted NRS values from the linear mixed model were significantly different between the groups. Compared with the control group, the combined therapy group had lower predicted NRS scores for the first 72 h, but higher predicted scores between 72 and 96 h. Moreover, the mean NRS scores over the first 48 h postoperation were significantly lower in the combined therapy group than in the control group; the scores were similar in both groups during the remaining period. With the exception of a higher body mass index in the CWIS group, the other variables, such as the dosage and usage time of fentanyl citrate, use of additional painkillers, and side effects, including wound complications, did not differ between groups. CONCLUSIONS: Combined therapy using CWIS and IV PCA may be a useful strategy for POSP management in gynecologic oncology patients.