title: The Effect of Deep Versus Moderate Neuromuscular Block on Surgical Conditions and Postoperative Respiratory Function in Bariatric Laparoscopic Surgery: A Randomized, Double Blind Clinical Trial.
abstract: In recent literature, it has been suggested that deep neuromuscular block (NMB) improves surgical conditions during laparoscopy; however, the evidence supporting this statement is limited, and this was not investigated in laparoscopic bariatric surgery. Moreover, residual NMB could impair postoperative respiratory function. We tested the hypotheses that deep NMB could improve the quality of surgical conditions for laparoscopic bariatric surgery compared with moderate NMB and investigated whether deep NMB puts patients at risk for postoperative respiratory impairment compared with moderate NMB.
  
  
  
  Sixty patients were evenly randomized over a deep NMB group (rocuronium bolus and infusion maintaining a posttetanic count of 1-2) and a moderate NMB group (rocuronium bolus and top-ups maintaining a train-of-four count of 1-2). Anesthesia was induced and maintained with propofol and remifentanil. The primary outcome measures were the quality of surgical conditions assessed by a single surgeon using a 5-point rating scale (1 = extremely poor, 5 = optimal), the number of intra-abdominal pressure increases >18 cmH2O and the duration of surgery. Secondary outcome measure was the postoperative pulmonary function assessed by peak expiratory flow, forced expiratory volume in 1 second, and forced vital capacity, and by the need for postoperative respiratory support. Data are presented as mean ± standard deviation with estimated treatment effect (ETE: mean difference [95% confidence interval]) for group comparisons.
  
  
  
  There was no statistically significant difference in the surgeon's rating regarding the quality of the surgical field between the deep and moderate NMB group (4.2 ± 1.0 vs 3.9 ± 1.1; P = .16, respectively; ETE: 0.4 [-0.1, 0.9]). There was no difference in the proportional rating of surgical conditions over the 5-point rating scale between both groups (P = .91). The number of intra-abdominal pressure increases >18 cmH2O and the duration of surgery were not statistically different between the deep and moderate NMB group (0.2 ± 0.9 vs 0.3 ± 1.0; P = .69; ETE: -0.1 [-0.5, 0.4] and 61.3 ± 15.1 minutes vs 70.6 ± 20.8 minutes; P = .07, ETE: -9.3 [-18.8, 0.1], respectively). All the pulmonary function tests were considerably impaired in both groups when compared with baseline (P < .001). There was no statistically significant difference in the decrease in peak expiratory flow, forced expiratory volume in 1 second, and forced vital capacity (expressed as % change from baseline) between the deep and the moderate NMB group.
  
  
  
  Compared with a moderate NMB, there was insufficient evidence to conclude that deep NMB improves surgical conditions during laparoscopic bariatric surgery. Postoperative pulmonary function was substantially decreased after laparoscopic bariatric surgery independently of the NMB regime that was used. The study is limited by a small sample size.
authors.affiliation: From the Departments of *Anesthesiology and †Abdominal Surgery, Intensive Care Medicine, Emergency Care and Pain Clinic, Ziekenhuis Oost-Limburg, Genk; and ‡Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.
authors.forename: Sam
authors.initials: S
authors.lastname: Baete
authors.forename: Gerd
authors.initials: G
authors.lastname: Vercruysse
authors.forename: Margot
authors.initials: M
authors.lastname: Vander Laenen
authors.forename: Pieter
authors.initials: P
authors.lastname: De Vooght
authors.forename: Jeroen
authors.initials: J
authors.lastname: Van Melkebeek
authors.forename: Dimitri
authors.initials: D
authors.lastname: Dylst
authors.forename: Maud
authors.initials: M
authors.lastname: Beran
authors.forename: Jan
authors.initials: J
authors.lastname: Van Zundert
authors.forename: René
authors.initials: R
authors.lastname: Heylen
authors.forename: Willem
authors.initials: W
authors.lastname: Boer
authors.forename: Sam
authors.initials: S
authors.lastname: Van Boxstael
authors.forename: Tom
authors.initials: T
authors.lastname: Fret
authors.forename: Hans
authors.initials: H
authors.lastname: Verhelst
authors.forename: Cathy
authors.initials: C
authors.lastname: De Deyne
authors.forename: Frank
authors.initials: F
authors.lastname: Jans
authors.forename: Pascal
authors.initials: P
authors.lastname: Vanelderen
mesh_terms: D000328:Adult; D050110:Bariatric Surgery / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D059325:Intra-Abdominal Hypertension / Q000453:epidemiology / Q000503:physiopathology; D010535:Laparoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019148:Neuromuscular Blockade / Q000379:methods*; D009767:Obesity, Morbid / Q000601:surgery; D011184:Postoperative Period; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012129:Respiratory Function Tests; D066231:Surgeons; D016896:Treatment Outcome