Blood Pressure Measurement

Abstract

An appreciation in the 18th century that blood in the arterial system is under considerable pressure was cited at the beginning of the previous chapter. In the subsequent two centuries techniques emerged for both the direct and indirect measurement of arterial blood pressure. Today, there is a continuing appraisal of these methods since indirect methods are vulnerable to error while the direct techniques require invasive procedures. The question of exactly what values for pressure should be considered abnormal has not yet been settled. Use of “mmHg” and “cm H2O” as standard units of pressure is slowly being replaced by the more scientific “Pascal.”