(994) The efficacy of continuous pre-peritoneal bupivacaine infusion in cesarean section

We evaluate the efficacy of local continuous subperitoneal infusion of bupivacaine (On-Q pump) in postoperative pain relief and reduce the requirement of opioids and other analgesics in women with cesarean section.

Study Design: Eligible women with cesarean section were randomly allocated to two groups (35 for the study group: bupivacaine and 35 for the control group: normal saline). They received a continuous preperitoneal infusion of either 0.25% bupivacaine or 0.9% normal saline for 48 h, based on their group allocation, through a multi-holed catheter. All patients also received intravenous fentanyl through an IV-PCA pump. They were followed up for accessing the pain scores (visual analog scale, VAS), consumption of IV-PCA, and other analgesics requirements 3 times; less than 8hour, postoperative day1(POD1), and 2 (POD2). The blood sample was obtained at POD1 and measured fentanyl concentration from maternal serum using liquid chromatography-Tandem mass spectrometry. An Independent T-test was used to compare the means of continuous variables, and the Mann-Whitney test was used for nominal variables.

Results:

 In a total of 69 patients (35 of the study group and 34 of the control group) analyzed, the mean VAS scores of the study group were lower at all three follow-ups than those of the control group, and significantly lower at POD2 (2.7± .0.9 Vs. 3.4 ± 1.32, P = 0.01). The IV-PCA consumption was significantly lower 3 times than the control group (less than 8h, POD1, and POD2, p=0.04, < 0.001 and < 0.001 respectively). Total administration of additional analgesics was significantly higher in the control group, and ketorolac, propacetamol, or pethidine were used. The 62 serum samples were measured for fentanyl concentration (30 of the study group and 32 of the control group) showed no difference between the two groups, and seven samples were below the measurable limit.

Conclusion: This study revealed that continuous preperitoneal bupivacaine infusion is effective for pain relief and reducing IV PCA and other analgesics requirements.