Deep Neuromuscular Relaxation Optimizing Low-Pressure Bariatric Surgery

This will be a double-blind randomized controlled trial comparing patients undergoing a deep neuromuscular blockade with a paralytic reversal agent versus patients undergoing standard anesthetic protocols in low-pressure pneumoperitoneum bariatric surgery. The study population will include patients aged 18-65 referred to St. Joseph's Healthcare for Roux-en-Y Gastric Bypass (RYGB) after completion of standard work-up for bariatric surgery through the Ontario Bariatric Network (OBN). The investigators plan to recruit and randomize 100 patients in a 1:1 ratio between deep NMB and standard anesthetic in low-pressure pneumoperitoneum bariatric surgery. Once enrolled in the study, patients will be assigned to one of the two groups using computer-based randomization on REDCap software. Allocation will be concealed until the time of the operation and will be provided directly to the anesthetist in opaque envelopes. The anesthetist will be aware of the assigned group, but the patient, surgeon, PACU nurses, ward nurses, research assistants and house staff will be blinded. The primary outcomes to be examined will include maximum intra-abdominal pressure, Leiden-Surgical Rating Scale, and postoperative pain scores. Secondary outcomes will include operative time, postoperative nausea, postoperative narcotic use, and length of stay.

• Deep Neuromuscular Blockade (Procedure): The proposed intervention in this study is delivery of an anesthetic with Deep Neuromuscular Blockage (NMB), which will be defined as a TOF of 0 and 2-3 twitches in the post-tetanic count.
• Sugammadex (Drug): Sugammadex will be used to reverse the deep neuromuscular blockade in the experimental group.

Primary outcomes

• Maximum IAP [Intraoperatively]: Maximum Intra-Abdominal Pressure, as assessed by the degree of pneumoperitoneum for each position (supine and reverse Trendelenburg)
• Leiden-Surgical Rating Scale [Intraoperatively]: Assessment of operating conditions, as assessed by the surgeon, assessed at the beginning of each position change (supine and reverse Trendelenburg). Scale ranges from 1 (extremely poor operating conditions) to 5 (optimal conditions).
• Postoperative Pain [Post Operative Day 1]: Postoperative pain as reported by the patient. Pain will be assessed on post operative day 1 at 8 am, noon, and 8pm, and an average pain score will then be calculated for post operative day 1. Pain will be assessed on an 11-point scale ranging from 0 (no pain) to 10 (most pain imaginable)

Secondary outcomes

• Operative Time [Intraoperative]: Two operative times will be recorded. The first will be related strictly to the surgery, from time of Veress needle insertion to time of removal of the final port. In addition, total operative time will also be recorded which will include time of induction and reversal of anesthesia
• Postoperative Nausea [Postoperative nausea scores will be recorded at 8 am, 2 pm, and 8pm on post operative day 1. Nausea will be measured on an 11-point scale ranging from 0 (no nausea) to 10 (most nausea imaginable).]: Postoperative nausea as reported by the patient
• Postoperative Narcotic Use [During index admission, up to one week.]: Amount of narcotic used by the patient postoperative
• Length of Stay [During index admission; through study completion, an average of 5 days]: Length of stay

Sex: All, ages: 18 Years to 65 Years

Inclusion Criteria:

* The patient meets NIH criteria for bariatric surgery and has not received a previous bariatric surgical procedure
* The patient is aged 18-65 years and has completed the screening and preparation process prescribed by the Ontario Bariatric Network

Exclusion Criteria:

* Inability to give informed consent
* ASA > 4
* Planned procedure other than RYGB or contraindications to RYGB
* BMI > 55 kg/m2
* Revisional procedure
* Allergies or suspected allergies to anesthetic medications (rocuronium or sugammadex)
* Renal insufficiency (GFR < 30ml/min)
* Family or personal history of malignant hyperthermia or personal history of neuromuscular disease
* History of chronic pain needing daily medications for the last >3 months

• Dennis Hong, MD, MSc, Principal investigator, Centre for Minimal Access Surgery