Enhancing Postoperative Analgesia After Cesarean Section: Insights Into Transversus Abdominis Plane Block, Intrathecal Opioids, and Other Analgesic Techniques

Background: Cesarean section (CS) is associated with moderate to severe pain that may delay recovery and interfere with the mother's ability to take care of the newborn. This clinical study aimed to evaluate different analgesic protocols for postoperative pain management after CS.

Methods: The study included 300 parturients scheduled for CS and classified into five equal groups as follows: general anesthesia (GA group), GA plus transversus abdominis plane (TAP) block (GA+TAP group), spinal anesthesia (SA) plus intrathecal fentanyl (ITF group), SA plus fentanyl + TAP block (ITF+TAP group), and SA plus intrathecal morphine (ITM group). Multimodal analgesia was added to all groups in the form of paracetamol 1 g/6 hours intravenously (IV), lornoxicam (8 mg/8 hours/IV), in addition to rescue opioid analgesia (morphine or oxycodone 4 mg/IV) upon the patient's request. Primary outcomes included pain assessments by numerical rating scale (NRS), worst and least pain scores, and time in maximum pain. Secondary outcomes included time to first request of analgesia, total opioid consumption, patient request for additional analgesia, function, and satisfaction scores. Possible side effects and neonatal Apgar scores were recorded at five and 10 minutes.

Results: The results showed a significant difference between the study groups regarding pain relief. The best pain relief, lowest worst pain, least pain, and total opioid consumption were reported by the ITM group, followed by ITF+TAP, GA+TAP, then SA, and GA groups (p < 0.05). The lower percentage of time in the worst pain and the longest time to the first request of analgesia were reported with ITM and ITF+TAP groups followed by the ITF group and GA+TAP group. In contrast, the longest time spent in the worst pain and the shortest duration until the first request of analgesia was observed in the GA group (p < 0.05). The best function scores were observed with ITF+TAP and then ITM, while the highest satisfaction scores were reported with ITM, ITF+TAP followed by SA and GA+TAP, and the lowest scores were observed in the GA group (p < 0.001 and p < 0.005, respectively). Side effects such as itching, nausea, and vomiting were significantly higher in the ITM group when compared to the other groups (p < 0.05). There were no significant differences between the study groups regarding the Apgar scores at five and 10 minutes (p = 0.271 and 0.760).

Conclusions: Bilateral TAP block has the potential to effectively enhance postoperative analgesia and reduce the need for systemic opioids after both GA and SA. Compared to ITF, ITM provides a higher quality and longer duration of analgesia with minimal analgesic-related side effects. Further studies to find an optimal analgesic protocol with few to no side effects are warranted.