title: Comparison of a standard CO₂ pressure pneumoperitoneum insufflator versus AirSeal: study protocol of a randomized controlled trial.
abstract: BACKGROUND
  AirSeal is a novel class of valve-free insufflation system that enables a stable pneumoperitoneum with continuous smoke evacuation and carbon dioxide (CO₂) recirculation during laparoscopic surgery. Comparison data to standard CO₂ pressure pneumoperitoneum insufflators is scarce. The aim of this study is to evaluate the potential advantages of AirSeal compared to a standard CO₂ insufflator.
  
  
  METHODS
  This is a single center randomized controlled trial comparing elective laparoscopic cholecystectomy, colorectal surgery and hernia repair with AirSeal (group A) versus a standard CO₂ pressure insufflator (group S). Patients are randomized using a web-based central randomization and registration system. Primary outcome measures will be operative time and level of postoperative shoulder pain by using the visual analog score (VAS). Secondary outcomes include the evaluation of immunological values through blood tests, anesthesiological parameters, surgical side effects and length of hospital stay. Taking into account an expected dropout rate of 5%, the total number of patients is 182 (n = 91 per group). All tests will be two-sided with a confidence level of 95% (P <0.05).
  
  
  CONCLUSIONS
  The duration of an operation is an important factor in reducing the patient's exposure to CO₂ pneumoperitoneum and its adverse consequences. This trial will help to evaluate if the announced advantages of AirSeal, such as clear sight of the operative site and an exceptionally stable working environment, will facilitate the course of selected procedures and influence operation time and patients clinical outcome.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01740011, registered 23 November 2012.
authors.affiliation: Department of General and Visceral Surgery, Krankenhaus der Barmherzigen Schwestern Linz, Seilerstätte 4, Linz 4020, Austria. ruzica-rosalia.luketina@bhs.at.
authors.forename: Ruzica Rosalia
authors.initials: RR
authors.lastname: Luketina
authors.forename: Michael
authors.initials: M
authors.lastname: Knauer
authors.forename: Gernot
authors.initials: G
authors.lastname: Köhler
authors.forename: Oliver Owen
authors.initials: OO
authors.lastname: Koch
authors.forename: Klaus
authors.initials: K
authors.lastname: Strasser
authors.forename: Margot
authors.initials: M
authors.lastname: Egger
authors.forename: Klaus
authors.initials: K
authors.lastname: Emmanuel
mesh_terms: D000328:Adult; D002245:Carbon Dioxide; D017081:Cholecystectomy, Laparoscopic / Q000379:methods*; D017558:Elective Surgical Procedures / Q000379:methods*; D059685:Herniorrhaphy / Q000379:methods*; D006801:Humans; D061646:Operative Time; D010149:Postoperative Pain / Q000209:etiology / Q000517:prevention & control; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D011312:Pressure; D012107:Research Design; D020069:Shoulder Pain / Q000209:etiology / Q000517:prevention & control
chemical_list: D002245:Carbon Dioxide