Accuracy of oscillometric blood pressure monitoring with concurrent auscultatory blood pressure in hemodialysis patients.

BACKGROUND

Oscillometric devices are commonly used to measure blood pressure and their validation entails sequential measurements of auscultated and oscillometric blood pressures. It is unknown whether simultaneous measurement of auscultated blood pressure and concurrent digitization and recording of the sounds can improve assessment of such devices. The aim of this study was to develop a technique of simultaneous measurement of blood pressure using oscillometric and auscultated measurements in the same deflation. Using such a device, we validated the Omron HEM-907 blood pressure measuring device in hemodialysis patients.

METHODS

Twenty non-hypertensive subjects and 20 hemodialysis patients were studied. Six blood pressure readings were obtained in each participant; three readings were obtained using the automatic, oscillometric mode of Omron HEM-907 and three readings were obtained using the manual mode of the Omron HEM-907. In each situation, simultaneous digitized Korotkoff sounds and manometric pressures were recorded. The grading scale indicated by the British Hypertension Society protocol was used to assess the device.

RESULTS

Systolic blood pressure measured simultaneously by digitized sound and pressures agreed closely for systolic pressure (Grade A for both hemodialysis and normal controls) but not for diastolic pressure (Grade C for both hemodialysis and controls). Sequential comparison of oscillometric readings with auscultated systolic and diastolic pressure yielded a Grade B for both hemodialysis patients and controls. When concurrent digitized systolic readings were used, however, Grade A was achieved for both populations for systolic readings, but Grade C for diastolic readings. The mean differences (SD) between the oscillometric and auscultatory blood pressure reading in normal controls were 4.3 (8.9) and 0.6 (8.7) for systolic and diastolic blood pressures, respectively. In hemodialysis patients, the mean differences (SD) were 2.7 (9.3) and 0.4 (7.0) for systolic and diastolic blood pressures, respectively.

CONCLUSION

Simultaneous measurement of digitized Korotkoff sounds and pressure can improve the assessment of devices for systolic but not diastolic blood pressure. The Omron HEM-907 device can be recommended for use in hemodialysis patients.