Comparison of the automated Dinamap blood pressure monitor with the mercury sphygmomanometer for detecting hypertension in the day case pre-assessment clinic

Abstract

Patients will be rejected from surgery by nurse-led pre-assessment clinics and will need to be assessed by their general practitioners if their blood pressure is higher than a pre-determined value. We have assessed the accuracy of the Dinamap automatic blood pressure recorder compared with manual mercury sphygmomanometry for detecting pre-operative hypertension in the day case pre-assessment clinic under everyday conditions. Two hundred consecutive patients attending for day case surgery pre-assessment had their blood pressure measured using the automated and the manual methods. We found that the Dinamap over-read systolic blood pressure by a mean of 8.38 mmHg and under-read diastolic pressure by a mean of 1.68 mmHg when compared with manual readings. Of the patients 6.5% would have been inappropriately diagnosed as hypertensive using the Dinamap and thus potentially rejected from day surgery and inappropriately referred to their general practitioner.