Clinical comparison of automatic, noninvasive measurements of blood pressure in the forearm and upper arm with the patient supine or with the head of the bed raised 45 degrees: a follow-up study.
BACKGROUND
Noninvasive measurement of blood pressure in the forearm is used when the upper arm is inaccessible and/or when available blood pressure cuffs do not fit a patient's arm. Evidence supporting this practice is limited.


OBJECTIVE
To compare noninvasive measurements of blood pressure in the forearm and upper arm of medical-surgical inpatients positioned supine and with the head of the bed raised 45 degrees .


METHODS
Cuff size was selected on the basis of forearm and upper arm circumference and manufacturers' recommendations. With a Welch Allyn Vital Signs 420 Series monitor, blood pressures were measured in the forearm and then in the upper arm of 221 supine patients with their arms resting at their sides. Patients were repositioned with the head of the bed elevated 45 degrees and after 2 minutes, blood pressures were measured in the upper arm and then the forearm. Starting position was alternated on subsequent subjects.


RESULTS
Paired t tests revealed significant differences between systolic and diastolic blood pressures measured in the upper arm and forearm with patients supine and with the head of the bed elevated 45 degrees . The Bland-Altman procedure revealed that the distances between the mean values and the limits of agreement were from 15 to 33 mm Hg for individual subjects.


CONCLUSIONS
Noninvasive measurements of blood pressure in the forearm and upper arm cannot be interchanged in medical-surgical patients who are supine or in patients with the head of the bed elevated 45 degrees .
Schell
Kathleen
K
University of Delaware, Newark, Delaware, USA.
Lyons
Denise
D
Bradley
Elisabeth
E
Bucher
Linda
L
Seckel
Maureen
M
Wakai
Sandra
S
Carson
Elizabeth
E
Waterhouse
Julie
J
Chichester
Melanie
M
Bartell
Deborah
D
Foraker
Theresa
T
Simpson
E Kathleen
EK
D000293:Adolescent; D000328:Adult; D001132:Arm; D001795:Blood Pressure Determination / Q000379:methods*; D005260:Female; D005542:Forearm; D006801:Humans; D008297:Male; D011187:Posture; D016683:Supine Position