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, self-controlled sequential design.

INTERVENTIONS: All patients had indwelling pulmonary artery catheters, and hypovolemia was confirmed by a pulmonary artery wedge pressure of 6 mm Hg or less. Hemodynamic and oxygen transport variables were measured with the patient supine and again ten minutes after placing the patient in the Trendelenburg position.

SETTING

University-affiliated tertiary care surgical ICU.

TYPE OF

PARTICIPANTS

Eight postoperative adults.

RESULTS

Mean arterial blood pressure increased from 64.9 +/- 4.9 to 75.6 +/- 3.5 mm Hg (P < .05), pulmonary artery wedge pressure increased from 4.6 +/- 1.1 to 7.9 +/- 0.8 mm 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 significant change in cardiac index, oxygen delivery, oxygen consumption, or oxygen extraction ratio.

CONCLUSION

The increase in blood pressure from Trendelenburg position is not associated with an improvement in blood flow or tissue oxygenation.