title: Factors Associated with Increased Experience of Postoperative Pain after Laparoscopic Gastric Bypass Surgery.
abstract: Patients with high body mass index (BMI), pre-existing pain and young age and women seem to experience more postoperative pain. Few studies have, however, addressed these risk factors amongst obese patients undergoing bariatric surgery. The aim of the present study was to evaluate risk factors for postoperative pain following laparoscopic gastric bypass surgery.
  
  
  
  In this cohort study, we used data from the PAIN OUT register for postoperative pain during the first 24 h after surgery. Primary outcome measure was severity of pain after surgery. Multivariate analyses were conducted to evaluate BMI, young age, gender and pre-existing pain as independent risk factors for postoperative pain.
  
  
  
  We included 192 patients in this study. Younger age (B -0.08, 95%CI -0.11 to -0.05/year; p < 0.001), female gender (B 0.92, 95%CI 0.10-1.75; p = 0.029) and pre-existing pain (B 1.06, 95%CI 0.03-2.09; p = 0.044) were all associated with an increased risk for postoperative pain. In the multivariate analyses, only young age ((adjusted OR 0.95, 95%CI 0.92-0.97/year; p < 0.001) and pre-existing pain (adjusted OR 2.56, 95%CI 1.09-6.00; p = 0.031) remained as independent risk factors for severe postoperative pain.
  
  
  
  Younger age and pre-existing pain are associated with severe postoperative pain during the first 24 h after laparoscopic gastric bypass surgery, whereas female gender and high BMI are not.
authors.affiliation: Department of Anaesthesiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
authors.forename: Markus
authors.initials: M
authors.lastname: Hartwig
authors.affiliation: Department of Anaesthesiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.|Department of Anaesthesiology and Intensive care, Örebro University Hospital, Örebro, Sweden.
authors.forename: Renée
authors.initials: R
authors.lastname: Allvin
authors.affiliation: Department of Anaesthesiology and Intensive care, Örebro University Hospital, Örebro, Sweden.
authors.forename: Ragnar
authors.initials: R
authors.lastname: Bäckström
authors.affiliation: Department of Surgery, Faculty of Medicine and Health, Örebro University, -70185, Örebro, SE, Sweden. erik.stenberg@regionorebrolan.se.
authors.forename: Erik
authors.identifier: 0000-0001-9189-0093
authors.initials: E
authors.lastname: Stenberg
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000601:surgery*; D010149:Postoperative Pain / Q000209:etiology*; D000071066:Patient Reported Outcome Measures; D012042:Registries; D012307:Risk Factors
keywords: Age; Gastric bypass; Laparoscopy; Obesity; Postoperative pain; Pre-existing pain; Risk factor; Sex