Experiments were carried out in a canine model to test the validity of skeletal muscle surface pH (pHM) measurements in predicting imbalances in the relationship of perfusion to metabolic demand. Under conditions of metabolic and respiratory alkalosis and acidosis, there were no perfusion deficits and pHM paralleled arterial pH (pHa). Graded hemorrhage, however, resulted in an early drop in pHM coincident with decreased arterial flow to the extremities long before there was any change in pHa or systemic blood pressure. A description of the clinical application of pHM monitoring, with examples, is included and illustrated by examples of its value in hypovolemia, regulation of flow in cardiopulmonary bypass, and in malposition of the arm.
Van De Water JM, Philips PA, Linton LA, Borst RW, Fisher WR. Muscle Surface pH MonitoringEvaluation and Clinical Application. Arch Surg. 1972;104(6):799-805. doi:10.1001/archsurg.1972.04180060049013