The challenge of measuring blood pressure accurately

Blood pressure (BP) measurement is one of the standard recordings in clinical practice, but is often prone to inaccuracies. Auscultatory methods of measuring BP using a mercury sphygmomanometer have been the mainstay of clinical BP measurement for over 100 years, but have gradually been replaced by automated measurement methods. Semi-automatic and automatic oscillometric devices are now the commonest methods for BP measurement, and are suitable for both clinic, and home BP measurement. Although this technology is important in acute and primary care settings, nurses must remain competent in manual measurement of BP. Whatever device is used, it must be properly validated, regularly maintained and recalibrated according to the manufacturer's instructions. This article will define BP and the factors that control and influence it. The challenges that occur in measuring clinical BP accurately and the advantages and disadvantages of mercury, aneroid and oscillometric sphygmomanometers will be outlined.