TRENDELENBURG POSITION AND OXYGEN-TRANSPORT IN HYPOVOLEMIC ADULTS

Study objective: To evaluate the effect of the Trendelenburg position on oxygen transport in hypovolemic patients. Design: A prospective, se lf-controlled sequential design. Interventions: All patients had indwe lling pulmonary artery catheters, and hypovolemia was confirmed by a p ulmonary artery wedge pressure of 6 mm Hg or less. Hemodynamic and oxy gen transport variables were measured with the patient supine and agai n ten minutes after placing the patient in the Trendelenburg position. Setting: University-affiliated tertiary care surgical ICU. Type of pa rticipants: Eight postoperative adults. Results: Mean arterial blood p ressure increased from 64.9 4.9 to 75.6 +/- 3.5 mm Hg (P < .05), pulmo nary artery wedge pressure increased from 4.6 +/- 1.1 to 7.9 +/- 0.8 m m Hg (P < .05), and the systemic vascular resistance rose to 2,965 +/- 210 from 2,302 +/- 199 dyne . sec/cm5 (P < .05). There was no signifi cant change in cardiac index, oxygen delivery, oxygen consumption, or oxygen extraction ratio. Conclusion: The increase in blood pressure fr om Trendelenburg position is not associated with an improvement in blo od flow or tissue oxygenation.