Analgesic Effects of Intrathecal Morphine and Transversalis Plane Block After Cesarean Delivery

It is known that cesarean deliveries are increasingly performed worldwide today. Cesarean operations can cause severe postoperative pain; inadequate control of this pain can lead to negative outcomes such as increased opioid requirements, delayed recovery, chronic pain syndrome, and postpartum depression . Furthermore, inadequate pain control may limit the mother's ability to care for her newborn, negatively affecting mother-newborn interaction, reducing breastfeeding success, and weakening the mother-baby bond.

The ideal analgesic approach should include agents that do not affect the mother's functions and have minimal transfer into breast milk. In this regard, current guidelines recommend multimodal analgesia protocols that include the use of neuraxial local anesthetics and opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), and paracetamol . Although morphine administered via the neuraxial route can provide effective analgesia for the first 12-24 hours postoperatively, its use may be limited due to undesirable side effects such as delayed respiratory depression, nausea, vomiting, and pruritus . For these reasons, alternative methods aimed at reducing opioid use have come to the fore in recent years. Fascial plane blocks performed under ultrasound guidance are recommended as a complementary part of multimodal analgesia in situations where neuroaxial opioids are not used or where analgesia control is inadequate. First described by Hebbard in 2009, the Transverse Fascial Plane Block (TFPB) provides analgesia by targeting the proximal branches of the T12 and L1 nerves between the transversus abdominis muscle and the transverse fascia. TFPB is used to relieve postoperative pain, particularly after lower abdominal surgeries, cesarean sections, and appendectomies.

Primary outcomes

• Pain intensity assessed by Numeric Rating Scale (NRS) [2nd, 6th, 12th, and 24th hours postoperatively]: Pain intensity, will be assessed using the Numeric Rating Scale ("0" no pain, "10" most severe pain experienced) at rest and during movement (passive flexion of the legs).

Secondary outcomes

• 1. Time to first opioid request [First 24 hours postoperatively]: Time from the end of surgery to the first postoperative opioid request, recorded in hours
• 2. Sedation Level [2, 6, 12 and 24 hours postoperatively]: Postoperative sedation level will be assessed at 2nd, 6th, 12th and 24 hours using Ramsay Sedation Scale (RSS) (1 = anxious or agitated, 2 = cooperative and oriented, 3 = responds to commands only, 4 = brisk responde to stimulus, 5 = sluggish response, 6 = no response)
• Incidence postoperative nausea and vomiting [First 24 hours postoperatively]: The presence of nausea and/or vomiting will be recorded during the first 24 postoperative hours PONV SCORE 0: No nausea or vomiting 1. Nause without vomiting 2. One episode of vomiting 3. More than one episode of vomiting
• Incidence of pruritis [First 24 hours postoperatively]: The incidence of pruritis will be recorded during the first 24 postoperative hours. Pruritus will be assessed using the following scale: 0: No pruritis 1. Mild pruritis (sensation without need to scratch) 2. Moderate pruritis ( requires scratching) 3. Severe pruritis (requires treatment)
• Obstetric Quality of Recovery -11(ObsQoR-11) Score [24 hours postoperatively]: Quality of recovery will be assessed using the Obstetric Quality of Recovery -11(ObsQoR-11) Score questionnaire, which concists of 11 items scored from 0 to 10, with a total score ranging from 0-110, where higher scores indicate better postoperative recovery.

Sex: Female, ages: 18 Years to 45 Years

Inclusion Criteria:

* Woman aged 18-45
* ASA physical status II
* Patients undergoing cesarean section under spinal anesthesia
* Patients received intrathecal morphine and bilateral TFB block.

Exclusion Criteria:

* Contraindications to spinal anesthesia
* ASA physical statu III- IV
* History of hypersensitivity or allergy to the study drugs
* Pregnancy-related diseases ( preeclampsia, eclampsia, gestational diabetes, gestational hypertension, placental abnormalities vb)
* Obesity (body mass index > 35 kg/m2)
* Cognitive impairment or inability to cooperate
* Alcohol or drug dependence
* Patients who do not provide informed consent

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• BETÜL YILMAZ, Specialist medical doctor, Principal investigator, Vezirkopru State Hospital