A Validation study on Blood Pressure Measurement in Adults - Aneroid Vs Automated Oscillometry in Comparison with Mercury Sphygmomanometry

BACKGROUND: In the recent years, many organizations have emphasized the urgent need to phase out mercury devices from health care. However, inaccurate blood pressure measurements from erroneous non-mercury devices may lead to misdiagnosis and either inadequate or unnecessary treatment of hypertension. Hence, the onus is on to identify the ideal instrument to measure blood pressure that ensures the accuracy of the mercury sphygmomanometer but is at the same time environment-friendly. OBJECTIVES: The purpose of this study was to compare aneroid and oscillometric blood pressure measurement in the adult population over a range of blood pressure values with reference to mercury sphygmomanometry. A sub group analysis was also done among hypertensives, geriatric population, patients in shock and patients in atrial fibrillation. METHODS: After ensuring adequate precautions, blood pressure measurements of 500 study subjects was taken as prescribed by the AHA guidelines. The recordings were taken in the mercury sphygmomanometer, aneroid sphygmomanometer and digital oscillometry and results were compared. RESULTS: For patients in shock, the readings from aneroid devices for systolic and diastolic blood pressures were more accurate in comparison with the mercury device (p values = < 0.001 for both systolic and diastolic) For the same patients, the systolic and diastolic blood pressure readings recorded by the digital device was significantly different from the mercury values (p values = 0.327 and 0.023 respectively). However for other patient groups, there was no statistically significant difference between the two devices. CONCLUSION: This study showed that the aneroid sphygmomanometer was the better device for replacement of mercury sphygmomanometers in health care, especially in patients who are in shock. For patients who are hemodynamically stable, the automated oscillometric device may still be used owing to its convenience but with caution due to its inter-manufacturer formulae variation and other pitfalls.