Comparison of direct and indirect measuring arterial blood pressure.

Blood pressure measurements can be obtained in the clinical setting by a variety of methods, direct and indirect, but with varying results. Disparities between direct and indirect blood pressure measurements are due in part to physiological considerations, but are largely conditioned by the frequency of the recording system. In this, the first of three parts, the authors conclude that comparative studies of direct and indirect blood pressure fall into two groups, those resulting in close agreement between methods, and those that do not. Subsequent issues will include recommendations for further study (part II, March-April 1981), and will examine their own study of a group of patients undergoing surgery (part III, May-June 1981).