Laparoscopic TAP Block for Sleeve Gastrectomy: Does Timing Matter
Condition: Obesity; Pain, Postoperative
MeSH terms: Pain, Postoperative
Study type: Interventional

Summary: 
      The goal of this study is to investigate whether an early intraoperative transverse abdominis
      plane block (TAP block) will provide superior analgesia to a late intraoperative TAP block. A
      fixed amount of bupivacaine will be used for the TAP block and the primary outcomes will be
      measured by patient reported numerical assessment scores for pain.
    

Detailed description: 
      This is a single blinded, prospective study designed to determine optimal timing of
      transverse abdominis plane block (TAP block) in laparoscopic gastric sleeve patients.
      Research has shown that administration of TAP block during these cases does show improved
      post-operative pain control. There are no trials specifically evaluating the timing of
      administration in regards to superiority of pain control. To the investigators knowledge, no
      prospective study has ever been done investigating whether TAP block performed at the
      beginning of the case versus at the end of the case makes a difference in the amount of
      relief experienced by the patient. the investigators hypothesize that early intra-operative
      block will be superior to late intra-operative block in both post-operative pain as well as
      decreased length of stay in hospital secondary to reduction in peripheral and central nervous
      system hyper excitability. Before beginning the research study, ~200 plain envelopes will be
      made each containing one option written on paper indicating early intra-operative or late
      intra-operative TAP block. There will be equal numbers of both options. It will be the
      responsibility of either the PI or sub-investigators to select a random envelope and bring it
      to the operating room at the time of surgery. All patients involved in the study will have
      given informed consent in the office prior to surgery. On the day of surgery after the
      patient is induced and intubated, the PI or sub-investigator will open the envelope revealing
      the timing of the TAP block. Depending on what is revealed from the envelope, the patient
      will either receive the early intra-operative TAP block or the late intra-operative TAP
      block. The TAP block will be performed using 60 ml for right sided TAP block (side of
      specimen extraction) and 30 ml for left sided TAP block (non extraction side). 30 ml of
      bupivicaine solution will also be used for intraperitoneal irrigation as is already routinely
      done during these cases by the primary surgeon for additional analgesia. This will be
      performed at the conclusion of all cases regardless of which arm the patient is in. For the
      early intra-operative TAP block, optiview trocar entrance will be performed in the upper
      abdomen followed by CO2 insufflation. After introduction of the camera into this trocar, the
      right lateral abdominal wall will be visualized with the laparoscope. An 18-gauge needle will
      be introduced externally at the center of the mid axillary line between the lower costal
      margin and the iliac crest until the surgeon feels a "pop," after which the surgeon will
      inject the first 2 mL of 0.25% bupivicaine to verify the correct position. Doyle's internal
      bulge sign (the bulge seen when the transversus abdominis muscle and peritoneum is pushed
      internally) will be visualized and the remainder of the 60 mL of 0.25% bupivacaine will be
      injected. The contralateral block will be performed according to the same technique but with
      only 30 ml of bupivicaine. The late post-operative block will be performed in the same
      fashion but after completion of the surgery just prior to removing the trocars and
      desufflation. The intraperitoneal irrigation with 0.25% bupivicaine solution will be
      performed at the end of the case using 30 ml total sprayed above the stomach, under the
      diaphragm, and over the bed of the spleen. All other medications intra-op and post-op
      including anesthesia will remain standardized according to the current HF Macomb bariatrics
      protocols. The data collection will take place immediately post-op, 4, 8, 12, 16, 20, and 24
      hours post-op using the numerical assessment score (NAS) for pain which will be performed at
      the time vitals are taken by the nursing aids. The investigators will also be analyzing
      post-operative vomiting and length of stay in hours.
    

Intervention name(s): TAP block
Intervention type(s): Procedure
Intervention description(s): An 18-gauge needle will be introduced externally at the center of the mid axillary line between the lower costal margin and the iliac crest until the surgeon feels a "pop," after which the surgeon will inject the first 2 mL of 0.25% bupivicaine to verify the correct position. Doyle's internal bulge sign (the bulge seen when the transversus abdominis muscle and peritoneum is pushed internally) will be visualized and the remainder of the 60 mL of 0.25% bupivacaine will be injected. The contralateral block will be performed according to the same technique but with only 30 ml of bupivicaine.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: This is a single blinded, prospective study designed to determine optimal timing of TAP block in laparoscopic gastric sleeve patients. Patients will randomly be assigned to the early intra-operative TAP block group or the late intra-operative TAP block group.
Masking: Single (Participant)
Primary purpose: Supportive Care
Keywords: TAP block; Obesity; Sleeve gastrectomy; Bariatrics; Post-operative pain