The Journal of Thoracic and Cardiovascular Surgery, Vol 72, 680-689, Copyright © 1976 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
The effect of positive end-expiratory pressure on regional ventilation and perfusion in the normal and injured primate lung
JW Hammon Jr, WG Wolfe, JF Moran, RH Jones and DC Sabiston Jr
Although positive end-expiratory pressure (PEEP) is being employed in the
management of respiratory insufficiency, many of its physiological effects
remain undetermined. The cardiopulmonary effects of PEEP as well as its
effect on regional ventilation and perfusion were studied in 10 baboons
before and after pulmonary injury with oleic acid. In the normal lung,
there was significant improvement in oxygenation at a PEEP of 5 cm. of
water secondary to improved ventilation and perfusion in all PEEP greater
than 5 cm. of water produced increasing mismatch of ventilation and
perfusion in all zones. After oleic acid was injected, hypoxemia was
evident with a reversal of the normal ventilation- perfusion (V/Q)
relationship between upper and lower lung zones. This mismatch of
ventilation and perfusion was corrected at a PEEP of 15 cm. of water. It
was reasonable to conclude that the use of PEEP in the injured lung exerts
it beneficial effect by balancing regional ventilation and perfusion in
addition to increasing functional residual capacity.