Passive Leg Raising Does Not Produce a Significant or Sustained Autotransfusion Effect

Publisher Website
Google Scholar
Abstract
Passive leg raising is widely used to treat hypotension associated with hypovolemia. Presumably, gravity causes a central translocation of leg venous blood and an increase in filling pressure, cardiac output and arterial pressure. Ten healthy [human] volunteers, 25-35 yr old, had measurements of heart rate, blood pressure and cardiac output in the supine position after 20 s and 7 min of 60.degree. passive leg elevation. The protocol was performed 3 and 45 min after the subjects changed from an ambulatory upright to a supine position. Stroke volume and cardiac output increased transiently (8-10%) when the legs were raised after 3 min rest in the supine position. By 7 min of leg elevation, these beneficial effects disappeared. After 45 min supine, leg raising had no effect on stroke volume or cardiac output but increased blood pressure (4 mm Hg) by increasing peripheral resistance (15%). Leg raising, like application of the MAST [medical anti-shock trousers], fails to produce any sustained increase in cardiac output or stroke volume. Small venous leg volumes and time-dependent changes in the distribution of venous volume and compliance may explain the absence of any sustained autotransfusion effect.

This publication has 0 references indexed in Scilit: