Transversus Abdominis Plane (TAP) Block in Laparoscopic Gastric-bypass Surgery

Study Overview
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Brief Summary
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Laparoscopic gastric-bypass surgery (LGBS) is one of the surgical treatments for morbid obesity, which is performed under general anesthesia. TAP block is an analgesic strategy covering the dermatomes from T6 to L1 and consists of injecting local anesthetic in the TAP between the costal margin and the iliac crest, where the thoracolumbar nerves (T6-L1) are located. As far as the investigators know, this analgesic technique has never been studied in LGBS. The investigators objective is to determine whether an ultrasound (US)-guided TAP block provides improved analgesia during the first 24 hours after laparoscopic gastric-bypass surgery, compared to conventional therapy only.

Official Title
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Is the Analgesic Effect of the Transversus Abdominis Plane (TAP) Block in Laparoscopic Gastric-bypass Surgery Useful?

Conditions
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Gastric-bypass Surgery, Opioid Consumption, Obesity

Intervention / Treatment
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* Procedure: TAP-Block
* Other: Conventional Managment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA physical status I-III 18-70 years of age, inclusive scheduled for elective laparoscopic gastric-bypass surgery. Exclusion Criteria: contraindications to regional blockade (e.g., allergy to local anesthetics, coagulopathy, malignancy or infection in the area) pregnancy history of alcohol or drug dependence/abuse history of long term opioid intake or chronic pain disorder history of significant psychiatric conditions that may affect patient assessment inability to understand the informed consent and demands of the study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

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: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Conventional management<br>On the ward, patients will be prescribed acetaminophen 1 g every 6 hours. If additional analgesia is required, patients will take oxycodone 5-10 mg up to every 2 hours or iv morphine. Patients with contraindications to oxycodone will be prescribed oral hydromorphone 1-2 mg instead. This is the current standard of care at Toronto Western Hospital. | Other: Conventional Managment<br>* For these group.no TAP block administration. just conventional management for post operative pain.<br>|
| Experimental: TAP Block+Conventional Management<br>The TAP block will be performed after the induction, before the surgery, by an anesthesiologist with experience of at least 10 successful TAP blocks.Also patients will be prescribed acetaminophen 1 g every 6 hours. If additional analgesia is required, patients will take oxycodone 5-10 mg(oral hydromorphone 1-2 mg) up to every 2 hours or iv morphine. | Procedure: TAP-Block<br>* Block needle will be inserted out-of-plane to the ultrasound beam, perpendicular to the skin surface, until the tip lies deep between the fascia of the transversus abdominis muscle and the internal oblique muscle. 30 ml of the study solution in each side will be injected at this location and should be observed to spread in an anterior-posterior direction between two muscles. Each patient will receive a total dose of 60 ml of 0.25% bupivacaine (150 mg) + 1:200,000 epinephrine.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Opioid consumption over the first 24 hours following LGBS. | Opioid consumption will be expressed in terms of milligrams doses of PO morphine. If other opioids are used, doses will be converted to the equivalent PO morphine dose using standard opioid dosage conversion tables. | 24 hrs | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain scores | Measured with a visual analogue scale (VAS, from 0 to 10), in the postoperative care unit, at rest and on movement (coughing). | 48 hours | 
| Opioid consumption at 48 hours | Opioid consumption expressed as milligram doses of PO morphine in the postoperative care unit and at 48 hours.If other opioids are used, doses will be converted to the equivalent PO morphine dose using standard opioid dosage conversion tables | 48 Hours | 
| Duration of block | starting after block administration till drop in sensory block injection | 48 hours | 
| Block procedure time | the time from placement of the ultrasound probe on the patient on one side to withdrawal of the needle on the other side; | 30 minutes | 
| TAP block complications | vascular puncture, intravascular local anesthetic injection and local hematoma; | 48 hours | 
| incidence of nausea and vomiting, and number of antiemetic medication administrations |  | during hospital stay average of 2 - 3 days | 
| incidence of itching, and number of antipruritic medication administrations |  | 48 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Laparoscopic gastric-bypass surgery, TAP block