title: Augmented spontaneous breathing and pulmonary gas exchange during pneumoperitoneum.
abstract: OBJECTIVE
  Ventilation of the lungs with positive end-expiratory pressure during pneumoperitoneum has been shown to improve the arterial partial pressure of oxygen. The implications of spontaneous breathing on pulmonary gas exchange remain unknown in this setting. We therefore sought to examine the influence of pressure-support ventilation with spontaneous breathing on gas exchange during simulated laparoscopy.
  
  
  METHODS
  Ten pigs were subjected to pneumoperitoneum at a pressure of 15 cmH2O. Animals received, in a random order, pressure-support and pressure-controlled ventilation for 60 min per mode. Inert gas and haemodynamic measurements were performed before changing to a subsequent mode.
  
  
  RESULTS
  Pressure-support ventilation was more efficient than pressure-controlled ventilation regarding perfusion of normal V(A)/Q lung areas (78 +/- 4% vs. 72 +/- 5%) (P < 0.05), alveolar-arterial partial pressure of oxygen difference (9.73 +/- 1.3 vs. 11.2 +/- 1.2 kPa) and arterial partial pressure of oxygen (14.93 +/- 1.6 vs. 13.7 +/- 2.0 kPa) (P < 0.05).
  
  
  CONCLUSIONS
  Pressure-support ventilation resulted in significantly better gas exchange than pressure-controlled ventilation in this model of simulated laparoscopy.
authors.affiliation: Leopold-Franzens University of Innsbruck, Department of Anaesthesiology and Critical Care Medicine, Innsbruck, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Loeckinger
authors.forename: C
authors.initials: C
authors.lastname: Hoermann
authors.forename: C
authors.initials: C
authors.lastname: Keller
authors.forename: K H
authors.initials: KH
authors.lastname: Lindner
authors.forename: A
authors.initials: A
authors.lastname: Kleinsasser
mesh_terms: D000818:Animals; D010535:Laparoscopy; D023421:Models, Animal; D011028:Pneumoperitoneum, Artificial; D011175:Positive-Pressure Respiration / Q000379:methods*; D011659:Pulmonary Gas Exchange; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics / Q000502:physiology; D013552:Swine; D014692:Ventilation-Perfusion Ratio