Early detection of hemorrhagic hypovolemia by muscle oxygen pressure assessment: preliminary report.

Skeletal muscle PO2 was studied during graded hemorrhagic shock in Labrador dogs by means of a polarographic needle PO2 electrode. Compared to hemodynamic, blood gas, biochemical, and hematologic variables, a shift to the left of the cumulative histogram of skeletal muscle PO2 was the earliest and most sensitive indicator of impaired skeletal muscle oxygenation. The mean arterial blood pressure and the mean of the medians of the skeletal muscle PO2, respectively, were as follows: during the control period 125 and 38.1 mm Hg, during the imminent shock period 143 and 24.5 mm Hg, and during the shock period 89 and 5.1 mm Hg. This electrode is suitable for clinical use.