Comparison of indirect and direct blood pressure measurements with Osler's manoeuvre in elderly hypertensive patients.

Indirect (cuff) and direct (intra-arterial) BPs were measured in 15 normotensive (mean age 79 years, range 72-88 years) and 21 hypertensive (mean age 76 years, range 65-89 years) elderly patients. Osler's test and arm arterial compliance, measured using Doppler-shifted ultrasound, were also assessed. In the normotensive, cuff systolic pressures were less than the direct by > 20 mmHg in 10 of the 15 (mean cuff systolic 139 +/- 13: direct 160 +/- 20 mmHg, P < 0.001); there was no statistical difference between the cuff and direct mean diastolic pressures (mean cuff diastolic 75 +/- 8; direct 70 +/- 10 mmHg). In the hypertensives, one had pseudohypertension (cuff systolic 186: direct 152 mmHg). However, cuff systolic pressures were less than the direct by > 20 mmHg in 11 (mean cuff systolic 205 +/- 26: direct 224 +/- 31 mmHg, P < 0.05); cuff diastolic pressures were greater than the direct by > 10 mmHg in 10 (mean cuff diastolic 102 +/- 14; direct 93 +/- 16 mmHg, P < 0.05). There was no significant difference between cuff and direct mean arterial pressures or the compliance in the normotensive and hypertensive groups. Osler's test was negative in the pseudohypertensive patient while in the four positive tests cuff systolic pressures were less than the direct measurements. In elderly patients there was no significant difference between the mean BP for cuff and direct measurements; systolic pseudohypotension and diastolic pseudohypertension are common and Osler's test is misleading.