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  • Meeting abstract
  • Open Access

Pulmonary gas exchange in pigs improves in the prone position with abdominal distension

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Critical Care19982 (Suppl 1) :P122

  • Published:


  • Oxygen
  • Partial Pressure
  • Ketamine
  • Emergency Medicine
  • Supine Position

Partial pressure of oxygen (PaO2) in arterial blood tend to be higher in the prone compared to supine position. Whether similar improvements in gas exchange occur in the presence of abdominal distension is not clear. We studied the effect of position on gas exchange in eight ketamine anesthetized, mechanically ventilated pigs with abdominal distension. A intraabdominal rubber balloon, was used to increase intraabdominal pressure. Gas exchange was measured in the supine and prone positions, with and without abdominal distension, in random order using the multiple inert gas elimination technique. In presence of normal abdomen, only PaO2 increased (P < 0.05). In contrast, in the prone position with abdominal distension, the PaO2 (P < 0.01) increased and AaPO2 (P < 0.05) and ÃA/ heterogeneity, indicated by log SD (P < 0.01) and [(a-A)D] area (P < 0.05) were decreased in the prone compared to the supine position. We conclude that the prone position increases PaO2 by improving gas exchange in pigs with abdominal distension.

Authors’ Affiliations

Departments of Anesthesiology, Medicine, Physiology, and Biophysics, University of Washington, Seattle, WA 98-195, USA


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