Ventilatory mechanics in hypovolemic shock

Abstract

In order to study ventilatory mechanics in shock, dogs were bled arterially into a reservoir, the height of which was regulated to keep the mean blood pressure of the animal at approximately 30 mm Hg. When the animal “took up” 40% of his maximal shed volume of blood (2–3 hr), the remainder of the blood was reinfused and the animal assumed to be in irreversible shock. Studies throughout the stages of hypovolemic and irreversible shock revealed a significant rise in lung compliance and a fall in combined viscous and air-flow resistance initially if the animal's lungs were carefully inflated prior to each study. As shock continued, there was a tendency for the lung compliance and resistance to air flow to return in the direction of the control values. Submitted on October 29, 1962