Pain Relieving Efficacy of TAP Block in Patients After Laparoscopic Gastric Bypass.
Condition: Pain; Obesity; Surgery; Neuromuscular Inhibition
MeSH terms: Obesity
Study type: Interventional
Phase: Phase 4

Summary: 
      The purpose of this study is to determine whether injection of bupivacaine into the TAP is
      effective in the treatment of post operative pain after laparoscopic gastric bypass
    

Detailed description: 
      Obesity surgery is expensive, although highly competitive to the cost of obesity related
      disease. An important step would be to reorganize obesity surgery into a day surgical
      procedure. Some reports already exist in the literature but the number of publications are
      sparse, and the description of the condition of the patient is limited. Our primary aim,
      therefore, is to investigate the influence transverses abdominis plane block has on pain
      after laparoscopic gastric bypass.

      The benefits of adequate postoperative analgesia are clear, and include a reduction in the
      postoperative stress response, reduction in postoperative morbidity and in certain types of
      surgery, improved surgical outcome. The benefits of utilizing regional analgesic techniques
      compared to systemic analgesics include reduction in pain intensity, decreased incidence of
      side effects from systemic analgesics and improved patient comfort. Effective pain control
      thereby accelerates recovery from surgery.

      A substantial component of the pain experienced by patients after abdominal surgery is
      derived from the abdominal wall incision.

      The Transversus Abdominis Plane (TAP) Block was first described in 2001 in a letter by Dr.
      Rafi. McDonnell et al have developed and tested the block and describes it as a landmark
      technique. TAP Block involves blocking the sensory afferent nerves that supply the anterior
      abdominal wall including the skin, muscles and the parietal peritoneum. Hebbard et al
      subsequently described an ultrasound guided technique for the TAP block which they named the
      Posterior TAP block. The posterior TAP block provides analgesia on the lower abdominal wall.
      Hebbard also described another ultrasound-guided technique called the Oblique Sub costal TAP
      block which provides analgesia for surgery on the upper abdominal wall.

      There is some debate over the extent of sensory blockade achieved by TAP block. Nerves
      supplying the anterior abdominal wall are derived from T16 to L1 and pass through this plane
      before supplying the anterior abdominal wall. Earlier studies showed a T7-L1 spread of the
      block after a single posterior TAP injection, while some newer studies revealed that the
      block failed to spread above T10 so was suitable only for lower abdominal procedures. In
      contrast the oblique sub costal TAP block can provide an effective analgesia after surgery
      that involves dermatome T6 to T10, in other word provide analgesia for surgery on the upper
      abdominal wall.

      Studies looking at posterior TAP block have demonstrated reduced postoperative morphine
      consumption and improved pain scores at rest and on movement in patients undergoing lower
      midline laparotomy, open appendectomy, laparoscopic appendectomy total abdominal
      hysterectomy, caesarean section and laparoscopic cholecystectomy. The duration of the
      morphine-sparing effect after a single shot injection into the posterior TAP has been
      reported to range from 12 to 48 hours. Pain scores both in rest and on movement are reduced
      compared to placebo in up to 48 hours after surgery. Single shot TAP blocks have also been
      used to provide analgesia in patients admitted to the ICU the analgesia provided by the block
      lasted between 16 to 24 hours.

      There has been a report from Leicester General Hospital of the effectiveness of inserting
      catheters into the oblique sub costal TAP. The obtained block provided analgesia for more
      than 72 hours in patients who have had surgery on the upper abdominal wall (hepatobiliary
      surgery). They also describe the block as being effective rescue analgesia in patients in
      whom the epidural is ineffective.

      Currently there are to our knowledge no clinical trials on the analgesic efficacy of single
      shot oblique sub costal TAP blocks for surgery of the upper abdominal wall. Niraj et al
      reports that they have observed the duration of postoperative analgesia to be 6 to 8 hours
      after single shot sub costal TAP. While Patil et al reports of sensory blockade for 5 hours
      along the dermatomal level T7-L1 after single shot posterior TAP block combined with sub
      costal TAP block.

      Oblique sub costal TAP block could be a viable alternative for providing analgesia during the
      postoperative period. The block can be performed easily using ultrasound guidance, has an
      excellent safety profile, provides effective dynamic analgesia and has a significant
      morphine-sparing effect.

      The proposed study involves the utilization of ultrasound to locate the oblique subcostal
      TAP, injection of bupivacaine or placebo (saline) into the TAP on each side and comparison of
      the analgesic efficacy of the TAP injection with that of placebo during two weeks in patients
      who have had gastric bypass.
    

Intervention name(s): Placebo: sterile normal saline; Marcaine
Intervention type(s): Drug; Drug
Intervention description(s): Bilateral TAP block using 20 ml of normal sterile saline per block.; Study group will receive a bilateral TAP block using 20 ml of 0,25% Marcain on each side.
Other intervention name(s): Saline water; Saline solution; Sodium chloride; NaCl; Salt; Bupivacaine
Intervention MeSH terms: Bupivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Supportive Care
Keywords: TAP block; Pain; Obesity; Surgery; Laparoscopic gastric bypass