title: Regional blood flows are affected differently by PEEP when the abdomen is open or closed: an experimental rabbit model.
abstract: OBJECTIVE
  The study of induced circulatory changes requires simultaneous assessment of multiple regional circulations because of interactions and compensatory mechanisms. Positive end expiratory pressure mechanical ventilation (PEEP) is known to cause marked, and potentially deleterious, cardiovascular changes. Our aim was to use a comprehensive approach to assess PEEP-induced circulatory changes in open vs closed abdomen animals.
  
  
  METHODS
  In the anesthetized rabbit, we used implantable Doppler micro-probes to measure blood flow simultaneously in the ascending aorta, inferior vena cava, portal vein, hepatic artery, common carotid artery, and renal artery. We studied spontaneously breathing animals (Group A), and open (Group B) and closed abdomen (Group C) animals mechanically ventilated at 0 (ZEEP) and 12 cm H(2)O PEEP.
  
  
  RESULTS
  In Group A, all biological and hemodynamic variables remained unchanged for three hours at the end of the surgical procedure. In Groups B and C, ZEEP produced no significant hemodynamic change. PEEP induced a decrease in carotid, hepatic, and renal artery blood flow in Groups B and C, a decrease in heart rate and mean arterial blood pressure in Group B, and a decrease in aorta blood flow in Group C.
  
  
  CONCLUSIONS
  These experimental results demonstrate the usefulness of the comprehensive approach of circulatory changes, and confirm that PEEP may have deleterious effects on regional blood flow, even without significant change in cardiac output, especially when the abdomen is open.
authors.affiliation: Department of Anesthesiology, Critical Care Medicine, and Emergency, Nîmes University Hospital, France.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Lefrant
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Juan
authors.forename: Pascal
authors.initials: P
authors.lastname: Bruelle
authors.forename: Roland
authors.initials: R
authors.lastname: Demaria
authors.forename: Robert
authors.initials: R
authors.lastname: Cohendy
authors.forename: Guy
authors.initials: G
authors.lastname: Aya
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Oliva-Lauraire
authors.forename: Pascale
authors.initials: P
authors.lastname: Peray
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Robert
authors.forename: Jean-Emmanuel
authors.initials: JE
authors.lastname: de La Coussaye
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Eledjam
authors.forename: Michel
authors.initials: M
authors.lastname: Dauzat
mesh_terms: D000005:Abdomen / Q000502:physiology; D000818:Animals; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000097:blood; D002339:Carotid Arteries / Q000502:physiology; D006339:Heart Rate; D011169:Portal Vein / Q000502:physiology; D011175:Positive-Pressure Respiration; D011817:Rabbits; D012039:Regional Blood Flow; D012079:Renal Circulation; D012121:Respiration, Artificial
chemical_list: D002245:Carbon Dioxide