Effects of endotoxin on canine skeletal muscle oxygen delivery-uptake relations during progressive hypoxic hypoxia.

Abstract

Septic patients, who may also have the adult respiratory distress syndrome (ARDS) often show apparent O2 supply dependency with elevated arterial lactate levels even at normal to high rates of O2 delivery (DO2) and appear unable to increase O2 extraction appropriately (Gilbert et al. 1986; Astiz et al. 1987). Cain (1986) has suggested that multiple events in the microcirculation may be responsible for this apparent defect in O2 extraction. These include microembolization and loss of endothelial functions and integrity. If the capillary membrane becomes leaky, then pericapillary edema may ensue and offer a diffusional block to the movement of O2 into tissue. The combination of microembolization and loss of endothelial functions that include microregional vascular control can lead to coexistence of underperfused and overperfused areas in a peripheral tissue, such as skeletal muscle. The outcome of these conditions would be a reduced ability of the tissues to extract O2 from arterial blood and an increased impediment to O2 diffusion.KeywordsMean Arterial PressureAdult Respiratory Distress SyndromeReactive HyperemiaIschemic HypoxiaHypoxic HypoxiaThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.