Health Technology Assessment Reports, 1989. Number 3. Cardiac Output by Electrical Bioimpedance

摘要

Electrical bioimpedance is a method used to determine stroke volume and cardiac output from thoracic tissue resistance to an imposed alternating electric current. The tissue resistance is inversely related to the thoracic blood content. When thoracic blood volume and blood flow velocity are calculated with an estimate of the intra-thoracic volume, and estimate of both stroke volume and cardiac output can be obtained. The basic rationale for the use of electrical bioimpedance for the measurement of cardiac output is that the procedure is mechanically noninvasive. In addition, electrical bioimpedance can determine cardiac output either continuously on a beat-to-beat basis, or intermittently at a frequently determined by the physician. Information obtained from a review of the literature, responses to a Federal Register notice of this assessment, PHS agencies and medical specialty groups suggested that despite the obvious potential advantages of electrical bioimpedance (e.g., noninvasiveness), the technique has not been validated in a trial with a statistically satisfactory number of subjects.