Use of a neonatal blood pressure cuff to monitor blood pressure in the adult finger--comparison with a standard adult arm cuff.

BACKGROUND: There are few suitable methods for monitoring blood pressure continuously (or intermittently) for research in adult stroke patients, who are ill but do not justify invasive intensive care monitoring.
METHOD: We tested a neonatal arm blood pressure in adults by placing it on the forefinger ("finger cuff"). We compared the repeatability of the finger cuff with blood pressure measured by a standard adult arm cuff using the oscillometric technique in 168 ambulatory outpatients attending a cerebrovascular disease clinic.
RESULTS: The mean difference between sequential mean blood pressure readings with the finger cuff was 0.55 mm Hg (95% confidence interval (CI) -14.36 to 15.47 mm Hg), and for the arm cuff was 3.31 mm Hg (95% CI -23.33 to 16.71 mm Hg). Measurements made with the arm cuff were shown to affect subsequent arm cuff readings made within a few minutes of the first. The mean difference between the finger cuff and arm cuff mean blood pressure readings was 0.03 mm Hg (95% CI -26.07 to 26.14 mm Hg) and agreement was better when the blood pressure was measured with the finger cuff first rather than the arm cuff. However, although there was no difference in the mean blood pressure recordings both systolic and diastolic blood pressure measurements differed systematically between arm and finger cuff.
CONCLUSION: The reproducibility of sequential blood pressure measurements made with the finger cuff was better than with the arm cuff. The performance of the finger cuff compared with that of the arm cuff was sufficiently good to encourage use of the finger cuff in research involving automatic intermittent monitoring to observe sequential blood pressures over time in stroke patients. However, measurements of systolic and diastolic pressure were not the same with the two cuffs and further work on calibration of the finger cuff would be useful.