Improving Pain Relief for Those Who Need It Most After Cesarean Delivery
Abstract Number: 87
Abstract Type: Original Research
Background: Severity of acute pain following delivery predicts pain and depression at 2 months postpartum.(1) We previously developed a 3-question pre-op survey to predict patients with post cesarean(C/S) pain in the top 20th percentile.(2) This double-blind randomized control trial tests whether a multimodal analgesic given to patients determined to be at risk for having high post-op pain will reduce pain in the hospital as well as persistent pain and depression at 2 months.
Methods: After IRB approval and informed consent, 60 women undergoing elective C/S, predicted by the 3-question pre-op survey to be in the top 20th percentile for post-op pain are randomized to receive either 150µg intrathecal(IT) morphine and oral placebo every 6 hrs for 24 hrs(control group), or 300µg IT morphine and 1g oral acetaminophen every 6 hrs for 24 hrs(study group). All patients receive spinal anesthesia with 12mg hyperbaric bupivacaine and 15-20µg of fentanyl, oral ibuprofen 800mg every 6 hrs, and IV PCA morphine. Edinburg and CES-D depression scales are assessed pre-op and at 2 months postpartum. Primary outcomes are VAS pain scores with movement at 24 hrs and secondary outcomes are pain and depression at 2 months postpartum. A group size of 60 is needed to show a 33% reduction in VAS of pain with movement between groups(power=0.8 and α=0.05). Unpaired t-tests and Chi-squares are used as appropriate. P<0.05 is considered significant.
Results: To date, 39 of 60 patients have been enrolled(21 study group, 16 control group, 2 excluded for protocol violation). Demographics, pre-op predictive scores, side effects, and 24 hr PCA morphine use were similar between groups. VAS pain scores at rest, with movement, and average pain over the first 24 hrs were all significantly lower in the study group (Table 1, P<0.05). 2 month persistent pain and depression data are being collected with results forthcoming.
Conclusion: This study represents the first time a simple pre-op test has been used to adjust dosing for C/S. The preliminary data suggests higher than standard doses and additional analgesics reduce acute pain in patients at risk for severe pain after C/S. If forthcoming 2 month data shows a significant reduction in pain and depression, such an approach would not only improve acute pain, but also important long term health outcomes representing significant public health burdens.
1 Eisenach et al. Pain 2008;140:87-94
2 Pan et al. Anesthesiology 2006;104:417–25