NEAR-INFRARED SPECTROSCOPY FOR NONINVASIVE ASSESSMENT OF CLAUDICATION

The purpose of this study was to explore the application of near-infra red spectroscopy (NIRS) to the assessment of peripheral arterial occlu sive disease (PAOD). Muscle blood flow, oxygen consumption, arterial i nflow capacity, O-2 resaturation, and recovery times were determined a t rest, under ischemic and hyperemic conditions, and continuously duri ng and after walking exercise in 11 claudicants and 15 nonclaudicants. Blood flow and oxygen consumption ((V) over dot O-2) at rest and bloo d flow following walking exercise did not differ significantly between claudicants and nonclaudicants. In contrast, (V) over dot O-2, after walking exercise was increased by a factor of 4.1 in claudicants compa red to a factor of 1.7 in nonclaudicants. The oxygen resaturation rate after arterial occlusion and the oxygen resaturation rate after walki ng exercise were significantly lower in claudicants. Claudicants showe d a higher degree of hemoglobin deoxygenation during walking exercise than nonclaudicants. A high postexercise (V) over dot O-2 is correlate d with a low ankle-brachial index (ABI). The resaturation rates and re covery times following walking exercise and arterial occlusion correla ted significantly with ABI parameters. A significant negative correlat ion was found between hemoglobin deoxygenation during exercise and the ABI parameters. A high correlation was observed between the oxygenate d hemoglobin (O(2)Hb) recovery time and the ABI recovery time after wa lking exercise. NIRS appears to be an effective noninvasive method for assessing the imbalance between oxygen demand and oxygen delivery in the leg muscles of PAOD patients at rest and during exercise. (C) 1997 Academic Press.