Correlation between skeletal muscle free fatty acid extraction and vascular decompensation during hemorrhagic hypotension.

The objective of this study was to determine whether or not a relationship exists between free fatty acid (FFA) extraction by skeletal muscle and onset of irreversible shock. Hind limb skeletal muscle vasculature of anesthetized dogs was surgically isolated from cutaneous tissue and subjected to a modified Wigger's hemorrhage shock protocol which was divided into five stages (I-V). Since the first signs of irreversibility began in stage II, this stage of hypovolemic hypotension was subdivided into IIa, IIb and IIc. Arterial and venous blood samples were taken during each stage for subsequent blood gas and FFA analysis. The data indicated that the onset of severe tissue ischemia and metabolic acidosis occurs concurrently with increased uptake of FFA and skeletal muscle vasodilation (decompensation). A possible physiological explanation for these observations could be related to an increased synthesis and release of PGE1. This agent has been shown by others to inhibit adrenergic neurotransmitter release causing loss of vascular tone.