Effect of variations in depth of neuromuscular blockade on rating of surgical conditions by surgeon and anesthesiologist in patients undergoing laparoscopic renal or prostatic surgery (BLISS trial): study protocol for a randomized controlled trial

BACKGROUND: Surgical conditions in laparoscopic surgery are largely determined by the depth of neuromuscular relaxation. Especially in procedures that are confined to a narrow working field, such as retroperitoneal laparoscopic surgery, deep neuromuscular relaxation may be beneficial. Until recently, though, deep neuromuscular block (NMB) came at the expense of a variety of issues that conflicted with its use. However, with the introduction of sugammadex, rapid reversal of a deep NMB is feasible. In the current protocol, the association between the depth of NMB and rating of surgical conditions by the surgeon and anesthesiologist is studied. METHODS/DESIGN: This is a single-center, prospective, randomized, blinded, parallel group and controlled trial. Eligible patients are randomly assigned to one of two groups: (1) deep NMB (post-tetanic count, one or two twitches; n = 12) and (2) moderate NMB (train-of-four, 1 to 2 twitches, n = 12) by administration of high-dose rocuronium in Group 1 and a combination of atracurium and mivacurium in Group 2. The NMB in Group 1 is reversed by 4 mg/kg sugammadex; the NMB in Group 2 by 1 mg neostigmine and 0.5 mg atropine. Patients are eligible if they are over 18 years, willing to sign the informed consent form, and are scheduled to undergo an elective laparoscopic renal procedure or laparoscopic prostatectomy. A single surgeon performs the surgeries and rates the surgical conditions on a five-point surgical rating scale (SRS) ranging from 1 (poor surgical conditions) to 5 (excellent surgical conditions). The intra-abdominal part of the surgeries is captured on video and a group of five anesthesiologists and ten surgical experts will rate the videos using the same SRS. The primary analysis will be an intention-to-treat analysis. Evaluation will include the association between the level of NMB and SRS, as obtained by the surgeon performing the procedure and the agreement between the scoring of the images by anesthesiologists and surgeons. DISCUSSION: We aim to show that under the right conditions the perceived opposing goals of surgeons and anesthesiologists (optimal surgical conditions vs. optimal postoperative conditions) may be met without compromise to either. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01631149.