Continuous Ropivacaine Subfascial Wound Infusion Compared With Intrathecal Morphine for Postcesarean Analgesia: A Prospective, Randomized Controlled, Double-Blind Study.

BACKGROUND

After cesarean delivery, postoperative pain management allows early rehabilitation and helps prevent postpartum depression and chronic pain. Our present prospective, randomized controlled, double-blind study assessed the duration and effect of intrathecal analgesia and continuous ropivacaine wound infiltration versus a control group after cesarean delivery. The primary outcome was analgesia duration, defined as time to first morphine request. Secondary outcomes were cumulative postoperative morphine consumption, number of patients who did not require IV morphine, incidence of adverse effects, and time to first ambulation.

METHODS

A total of 192 full-term parturients undergoing elective cesarean delivery were randomly allocated into 3 groups (control, morphine, and catheter). All patients received spinal anesthesia with 10 mg bupivacaine 0.5% hyperbaric bupivacaine (2 mL) + 5 μg of sufentanil (1 mL) and a multiholed catheter inserted into the wound. In the control group, NaCl 0.9% was administered intrathecally (0.1 mL) and through the catheter. The morphine group received 100 μg morphine (0.1 mL) intrathecally and NaCl 0.9% infused through the wound catheter. The catheter group received 0.1 mL NaCl 0.9% intrathecally and ropivacaine 0.2% infused in the catheter. Each patient received a 15-mL bolus of the dedicated solution through the catheter, which was connected to an elastomeric pump infusor delivering the same solution at a rate of 10 mL/h for 30 hours. All patients also received multimodal analgesia including acetaminophen and diclofenac. Analgesia duration was defined as the time from spinal injection (T0) to first IV morphine requirement (T1) administered via a patient-controlled IV analgesia pump. Statistical data analyses included use of the Kruskal-Wallis rank-sum test followed by the post hoc Tukey test and χ test.

RESULTS

The duration of postoperative analgesia was increased with intrathecal morphine (380 minutes; 215-1527) and ropivacaine wound infusion (351 minutes; 227-594) compared with the control (247 minutes; 182-338) with effect sizes of 0.171 (0.043-0.293) for morphine versus control and 0.164 (0.052-0.271) for catheter versus control. There was no difference between the morphine group and catheter group (effect size, 0.007; -0.118 to 0.132). Cumulative postoperative morphine consumption was also significantly lower in the morphine group and catheter group compared with the control group. The incidence of adverse effects did not differ between groups.

CONCLUSIONS

After elective cesarean delivery, 100 μg intrathecal morphine and ropivacaine wound infusion both increased the duration and effect of postcesarean analgesia without increased incidence of side effects.