Transversus Abdominis Plane (TAP) Block Versus Intrathecal Morphine for Caesarean Section - Randomised Controlled Trial

Study Overview
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Brief Summary
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Analgesia after cesarean section is still not satisfactory for many women. Even if pain reduction is sufficient with the technique of intrathecal morphine injection, side effects such as nausea and pruritus are common. Since several years, an alternative technique has been studied, the transversus abdominis plane (TAP)-block. Here a local anesthetic is injected in the abdominal wall muscles, and this has been shown to give a similar analgesic effect compared to intrathecal morphine, with potentially less side effects. With this study, we want to evaluate if the TAP-block yields indeed less side effects when compared with intrathecal morphine. The study will be a prospective study with the patients randomized to either a group with intrathecal morphine or a group with TAP-block.

Official Title
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Transversus Abdominis Plane (TAP) Block Versus Intrathecal Morphine for Caesarean Section - Randomised Controlled Trial

Conditions
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Postoperative Pain

Intervention / Treatment
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* Other: spinal anesthesia with intrathecal morphine
* Other: TAP-block with ropivacaine and clonidine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects must satisfy all of the following criteria to be enrolled into the study: American Society of Anesthesiology (ASA) physical status less than 3 Able to read and understand the information sheet and to sign and date the consent form Scheduled for elective C-section planned with spinal anaesthesia Age>18 Exclusion Criteria: Potential subjects who meet any of the following criteria will be excluded from participating in the study: Complicated pregnancy defined as having preeclampsia or placenta accreta, increta and percreta. Drug addiction. Contraindication to spinal anaesthesia (history of clotting disorders, septicemia, local infection at the injection site, spinal malformation, elevated intracranial pressure) Contraindication to TAP block (skin infection, abdominal wall muscle defect such as hernia and previous abdominal wall mesh). BMI>40 kg/m2 Weight less than 50 kg the day of the C-section. Height less than 150 cm or more than 175 cm. Allergy/contraindication to any medication used in the study. Previous median abdominal incision. Necessity to perform the C-section urgently before the scheduled date (with less than 24h preparation time).

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: treatment versus placebo
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: morphine group<br>spinal anesthesia with intrathecal morphine | Other: spinal anesthesia with intrathecal morphine<br>* in addition to the standard spinal anesthesia drugs (bupivacaine and fentanyl), morphine is added<br>|
| Experimental: TAP group<br>TAP-block with ropivacaine and clonidine | Other: TAP-block with ropivacaine and clonidine<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cumulative incidence of nausea and/or vomiting at 24 hours | Data for this endpoint will be gathered at 6h and 24h postoperatively from nurses' records in the recovery room (at 6h) and on the ward (at 24h), and counterchecked by asking the patient | 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cumulative incidence of pruritus at 24h | inquired directly from the patient at 6 and 24h | 24 h | 
| Cumulative incidence of treated nausea and vomiting at 24h | (inquired directly from the patient at 6 and 24h). | 24h | 
| Cumulative incidence of sedation at 6 and 24h. | Sedation defined as an observer's assessment of alertness and sedation (OAAS) score lower than 4 | 24h | 
| Cumulative incidence of arterial hypotension | defined as a systolic blood pressure of less than 100 mmHg for longer than 5 minutes (from nurse records at 6 and 24h) | 24h | 
| Cumulative incidence of bradycardia | defined as a heart rate of less than 50/min for longer than 5 minutes (from nurse records at 6 and 24h) | 24h | 
| Cumulative incidence of respiratory depression | defined as a respiratory frequency of less than 8/min for longer than 5 minutes (from nurse records at 6 and 24h | 24h | 
| Cumulative morphine consumption at 24 hours | (recorded in the memory of the patient controlled analgesia (PCA) pump). | 24h | 
| Time until first PCA request | (recorded in the memory of the PCA pump | 24h | 
| Pain score at rest at 6, 24 and 48 hours postoperatively | using the NRS scale (0-10) | 48h | 
| Pain score on movement | at 24 and 48 hours postoperatively (using the numerical rating scale (NRS 0-10)). | 48h | 
| Maternal satisfaction at 24 and 48 hours postoperatively | measured on a numeric rating scale (at 6h) and with the questionnaire quality of recovery (QoR40) at 24 and 48h | 48h | 
| persistent pain at 3 and 6 months postoperatively | Pain at rest, 0-10 pain scale; Pain on movement, 0-10 pain scale; Yes/no for scar pain;Yes/no for analgesic use | 6 months |