title: Reduction of CO(2)-pneumoperitoneum-induced metabolic hypoxaemia by the addition of small amounts of O(2) to the CO(2) in a rabbit ventilated model. A preliminary study.
abstract: BACKGROUND
  CO(2)-pneumoperitoneum used in endoscopic surgery induces system effects by CO(2) absorption. This study investigated the effect of the addition of O(2) to CO(2)-pneumoperitoneum, upon CO(2) absorption.
  
  
  METHODS
  The effect of a pneumoperitoneum using 100% CO(2) or 94% CO(2) + 6% O(2) upon arterial blood gases, acid base and O(2) homeostasis was evaluated. In series A suboptimal ventilation and a pneumoperitoneum pressure (PP) of 10 mmHg was used. In series B adequate ventilation and PP of 6 mmHg was used.
  
  
  RESULTS
  CO(2)-pneumoperitoneum profoundly affected blood gases and acid base homeostasis i.e. increasing pCO(2), HCO(3)(P < 0.001) and lactate concentrations (P < 0.05) and decreasing pH, actual base excess and standard bicarbonate (P < 0.001), resulting in metabolic hypoxaemia with desaturation, lower pO(2) (P < 0.001) and O(2)Hb (P < 0.05). These effects were more pronounced with higher PP and suboptimal ventilation.
  
  
  CONCLUSIONS
  CO(2)-pneumoperitoneum profoundly affected blood gases and acid base homeostasis resulting in metabolic hypoxaemia. The addition of 6% of O(2) to the CO(2)-pneumoperitoneum prevented these effects to a large extent. If these preliminary data are confirmed in the human, the addition of a few percent of O(2) to CO(2) could become important for endoscopic surgery of long duration, especially in obese patients with limited cardiorespiratory adaptation and steep Trendelenburg.
authors.affiliation: Centre for Surgical Technologies, Faculty of Medicine, Katholieke Universiteit Leuven, Belgium. ospanmynbaev@hotmail.com
authors.forename: Ospan A
authors.initials: OA
authors.lastname: Mynbaev
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Molinas
authors.forename: Leila V
authors.initials: LV
authors.lastname: Adamyan
authors.forename: Bernard
authors.initials: B
authors.lastname: Vanacker
authors.forename: Philippe R
authors.initials: PR
authors.lastname: Koninckx
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000009:adverse effects*; D004724:Endoscopy / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000517:prevention & control*; D023421:Models, Animal; D010100:Oxygen / Q000008:administration & dosage; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects / Q000379:methods*; D011817:Rabbits; D012121:Respiration, Artificial
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen