Lower-Extremity Arterial Air Plethysmography Evaluation

Abstract

Plethysmography is a noninvasive technique based on detecting small volume changes in the limb secondary to the cardiac cycle. These changes provide a methodology for qualitative assessment of arterial waveforms and are obtained in conjunction with the measurement of systolic blood pressures. The quality of the waveform is directly related to technical components of the study as well as physical components of the patient. Interpretation of the waveform includes the utilization of qualitative waveform descriptor categories, comparison of waveforms to adjacent ipsilateral levels, as well as contralateral waveforms at the same level. Examples of normal findings and various levels of arterial occlusive disease states will demonstrate the practical application of this testing technique. However, plethysmography does have a number of potential sources of error that must be recognized to ensure the study is of diagnostic quality. These potential pitfalls are described as well as some important considerations to provide the most accurate information. Although other studies may provide greater detail about the presence and location of arterial occlusive disease, plethysmography does provide an efficient and cost-effective method to assist in the diagnosis and management of the disease process.