Physiologic effects of steep positioning in the surgical intensive care unit
L. D. Nelson and H. B. Anderson
Department of Surgery, University of Miami.
Ten hemodynamically stable patients requiring mechanical ventilation for
radiographically symmetric acute lung disease were studied during steep
lateral positioning and continuous rotation in a Roto Rest kinetic
treatment bed. There were no significant hemodynamic or ventilatory
differences among the four positions (supine, right side down, left side
down, and rotating). In four patients, arterial oxygen pressure (PaO2)
decreased 16% to 49% in the lateral position when compared with the supine
position. Continuous rotation restored the PaO2 toward the supine value in
each patient. In six patients, PaO2 increased 11% to 35% during lateral
positioning. In five of the six patients, the increase in PaO2 differed
between sides, suggesting asymmetric lung disease. Continuous rotation did
not significantly alter the PaO2 from the supine values in these patients.
Adverse effects on oxygenation caused by positional changes may be reversed
by continuous rotation using the Roto Rest kinetic bed.
