title: What is the optimal device for carbon dioxide deairing of the cardiothoracic wound and how should it be positioned?
abstract: OBJECTIVE
  To compare recently described insufflation devices for efficient carbon dioxide (CO(2)) deairing of the cardiothoracic wound and to determine the importance of their position.
  
  
  METHODS
  Experimental and clinical.
  
  
  METHODS
  A cardiothoracic operating room at a university hospital.
  
  
  METHODS
  A full-size torso with a cardiothoracic wound and 10 patients undergoing cardiac surgery.
  
  
  METHODS
  Insufflation of CO(2) into the wound cavity at 2.5, 5, 7.5, and 10 L/min with a multiperforated catheter and a 2.5-mm tube with either a gauze sponge or a gas-diffuser of polyurethane foam at its end. The devices were tested when positioned at the level of the wound opening and 5 cm below and after exposure to fluid.
  
  
  RESULTS
  Deairing was assessed by measuring the remaining air content at the right atrium. With the multiperforated catheter, the gauze sponge, and the gas-diffuser, the lowest median air content in the torso was 8.4%, 2.5%, and 0.3%, respectively (p < 0.001), when positioned inside the wound cavity. When exposed to fluid, the gauze sponge and the multiperforated catheter immediately became inefficient (70% and 96% air, respectively), whereas the gas-diffuser remained efficient (0.4% air). During surgery, the gas-diffuser provided a median air content of 1.0% at 5 L/min, and 0.7% at 10 L/min.
  
  
  CONCLUSIONS
  For efficient deairing, CO(2) has to be delivered from within the wound cavity. The gas-diffuser was the most efficient device. In contrast to a gas-diffuser, a multiperforated catheter or a gauze sponge is unsuitable for CO(2) deairing because they will stop functioning when they get wet in the wound.
authors.affiliation: Department of Cadiothoracic Surgery and Anesthesiology, Huddinge University Hospital, Karolinska Institute, Stockholm, Sweden. m.persson@labmed.ki.se
authors.forename: Mikael
authors.initials: M
authors.lastname: Persson
authors.forename: Peter
authors.initials: P
authors.lastname: Svenarud
authors.forename: Jan
authors.initials: J
authors.lastname: van der Linden
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001826:Body Fluids; D002245:Carbon Dioxide / Q000008:administration & dosage*; D006348:Cardiac Surgical Procedures / Q000295:instrumentation*; D004618:Embolism, Air / Q000209:etiology / Q000517:prevention & control; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D006325:Heart Atria / Q000033:anatomy & histology; D006801:Humans; D007327:Insufflation / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D035423:Thoracic Cavity / Q000033:anatomy & histology / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D002245:Carbon Dioxide