Surgical Conditions During Laparoscopic Bariatric Surgery

A Prospective Randomized Clinical Trial Evaluating Surgical Conditions During Laparoscopic Bariatric Surgery With Deep Versus Moderate Neuromuscular Blockade

Obesity affects more than 78 million adults in the United States and it is estimated that 35% of the US population is obese. Currently, more than 179,000 bariatric procedures are performed in the US each year with the majority of these surgeries using laparoscopic techniques. Surgeons often request deep neuromuscular blockade (NMB) during surgery, but there is no evidence that a deep NMB improves surgical conditions and that the surgeons can discriminate between a moderate and deep NMB. There is also evidence that maintaining low insufflation pressures during laparoscopic surgery may decrease postoperative pain. The goal of this prospective, randomized, assessor-blinded controlled trial is to test the hypothesis that deep NMB provides optimal surgical conditions during laparoscopic bariatric surgery in the morbidly obese patient. It will also determine if deep NMB allows the surgeon to utilize lower insufflation pressure and decreases postoperative pain requirements after laparoscopic bariatric surgery.

Subjects will be randomized to one of four groups: moderate neuromuscular block (NMB) + 10 mm insufflation pressure (IP); moderate NMB + 15 mm IP; deep NMB + 10 mm IP; or deep NMB + 15 mm IP. A moderate NMB block will be defined as 2-3 twitches in the train of four (TOF) and a deep NMB will be defined as 0-1 posttetanic count. The surgeons will be asked to rate their satisfaction with the surgical conditions using a five-point ordinal scale ranging from 1 (extremely poor) to 5 (optimal conditions). The first rating will occur at the beginning of the procedure when the NMB level is stable at either a deep or moderate block and the intra-abdominal pressure is either 10 or 15 mm Hg (per randomization). The surgeon will be blinded to the insufflation pressure at this point. If the surgical conditions are rated as extremely poor or poor, the level of the neuromuscular block can be increased and/or the insufflation pressure can be increased to 15 mm Hg.

participants will be given the muscle relaxant, rocuronium, iv to obtain a moderate neuromuscular block (NMB) which is defined as 2-3 twitches in the train of four on a neuromuscular junction monitor. The initial insufflation pressure for the laparoscopy will be 10 mm Hg pressure.

participants will be given the muscle relaxant, rocuronium, iv to obtain a moderate NMB which is defined as 2-3 twitches in the train of four on a neuromuscular junction monitor. The initial insufflation pressure for the laparoscopy will be 15 mm Hg pressure. This arm represents the usual operating conditions for this type of surgery at the University hospital.

participants will be given the muscle relaxant, rocuronium, iv to obtain a deep NMB which is defined as 0-1 posttetanic counts on a neuromuscular junction monitor and the initial insufflating pressure will be 10 mm Hg. The initial insufflation pressure for the laparoscopy will be 10 mm Hg pressure.

participants will be given the muscle relaxant, rocuronium, iv to obtain a deep NMB which is defined as 0-1 posttetanic counts on a neuromuscular junction monitor and the initial insufflating pressure will be 15 mm Hg. The initial insufflation pressure for the laparoscopy will be 10 mm Hg pressure.

Rocuronium will be administered to achieve either a moderate (2-3 twitches) or deep (0-1 posttetanic) block depending on the group assignment

The initial insufflation pressure will be set at either 10 or 15 mm Hg depending on the group assignment

The surgeon will grade his satisfaction with the surgical conditions using a 5 point scale with 1 - extremely poor; 2 - poor; 3 - acceptable; 4. good; 5 - optimal surgical conditions

The patients will be randomized to an initial insufflation pressure of 10 or 15 mm hg. If the surgeons are not satisfied with the initial operating conditions, the insufflating pressure will be increase to 15 mm Hg (if not already at that level). This will be reported as the percentage of patients who were able to have their entire surgery performed at an insufflation pressure of 10 mm Hg.

The participants will be given iv fentanyl or hydromorphone after surgery. They will also be given po oxycodone. The investigators will collect data on the amount of opioid that is required after surgery. This will be reported as morphine equivalents using the morphine equivalent calculator at:

Inclusion Criteria: Age ≥ 18 years ASA I-III BMI ≥ 35 Exclusion Criteria: Inability to obtain written informed consent Pregnancy or breastfeeding Allergy to rocuronium, sugammadex, or any anesthetic agents used in the protocol Known or suspected neuromuscular disorders Significant renal disease with a serum creatinine ≥ 2 mg/dl f. Significant liver disease g. A family history of malignant hyperthermia