title: Effect of positive end-expiratory pressure on oxygen delivery during 1-lung ventilation for thoracoscopy in normal dogs.
abstract: OBJECTIVE
  To evaluate the effect of positive end-expiratory pressure (PEEP) on oxygen delivery (DO(2)) with 1-lung ventilation during thoracoscopy in normal anesthetized dogs.
  
  
  METHODS
  Prospective, controlled experimental study.
  
  
  METHODS
  Eight, adult, intact Walker Hound dogs weighing 25.6-29.2 kg.
  
  
  METHODS
  Anesthetized dogs had 1-lung ventilation during an open-chest condition. A Swan-Ganz catheter was used to measure pulmonary hemodynamic variables and to obtain mixed venous blood samples for blood gas analysis. A dorsal pedal catheter was used for measurement of systemic arterial pressure and to obtain arterial blood samples for blood gas analysis. Oxygen delivery was calculated and used to assess the effect of 0, 2.5, and 5 cm H(2)O PEEP during 1-lung ventilation on cardiopulmonary function. Each dog was its own control at 0 cm H(2)O PEEP. A randomized block ANOVA for repeated measures was used to evaluate the effect of the treatment on hemodynamic and pulmonary variables.
  
  
  RESULTS
  Use of 5 cm H(2)O PEEP induced a significant augmentation in the arterial partial pressure of oxygen (PaO(2)). Shunt fraction (Q(s)/Q(t)), physiologic dead space (V(D)/V(T)), and the alveolar-arterial oxygen difference (P(A-a)O(2)) decreased significantly after 5 cm H(2)O PEEP, compared with 1-lung ventilation without PEEP. Use of 2.5 cm H(2)O PEEP had no significant effect on cardiopulmonary variables. Use of PEEP had no significant effect on arterial oxygen saturation (SaO(2)), DO(2), and hemodynamic variables in normal dogs.
  
  
  CONCLUSIONS
  PEEP had no effect on DO(2) in normal dogs undergoing open-chest 1-lung ventilation because it had no adverse effect on hemodynamic variables.
  
  
  CONCLUSIONS
  PEEP in normal dogs during open-chest 1-lung ventilation for thoracoscopy is not detrimental to cardiac output and can be recommended in clinical patients.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, USA.
authors.forename: Simon T
authors.initials: ST
authors.lastname: Kudnig
authors.forename: Eric
authors.initials: E
authors.lastname: Monnet
authors.forename: Miriam
authors.initials: M
authors.lastname: Riquelme
authors.forename: James S
authors.initials: JS
authors.lastname: Gaynor
authors.forename: Denise
authors.initials: D
authors.lastname: Corliss
authors.forename: Mowafak D
authors.initials: MD
authors.lastname: Salman
mesh_terms: D000769:Anesthesia, Inhalation / Q000662:veterinary; D000818:Animals; D001784:Blood Gas Analysis / Q000662:veterinary; D018592:Cross-Over Studies; D004285:Dogs; D005260:Female; D006439:Hemodynamics; D008168:Lung / Q000502:physiology*; D008297:Male; D010100:Oxygen / Q000097:blood / Q000378:metabolism*; D011175:Positive-Pressure Respiration / Q000662:veterinary*; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000379:methods / Q000662:veterinary*; D019616:Thoracic Surgical Procedures / Q000379:methods / Q000662:veterinary; D013906:Thoracoscopy / Q000379:methods / Q000662:veterinary
chemical_list: D010100:Oxygen