title: Clinical comparison of automatic, noninvasive measurements of blood pressure in the forearm and upper arm.
abstract: BACKGROUND
  When the upper arm (area from shoulder to elbow) is inaccessible and/or a standard-sized blood pressure cuff does not fit, some healthcare workers use the forearm to measure blood pressure.
  
  
  OBJECTIVE
  To compare automatic noninvasive measurements of blood pressure in the upper arm and forearm.
  
  
  METHODS
  A descriptive, correlational comparison study was conducted in the emergency department of a 1071-bed teaching hospital. Subjects were 204 English-speaking patients 6 to 91 years old in medically stable condition who had entered the department on foot or by wheelchair and who had no exclusions to using their left upper extremity. A Welch Allyn Vital Signs 420 series monitor was used to measure blood pressure in the left upper arm and forearm with the subject seated and the upper arm or forearm at heart level.
  
  
  RESULTS
  Pearson r correlation coefficients between measurements in the upper arm and forearm were 0.88 for systolic blood pressure and 0.76 for diastolic blood pressure (P < .001 for both). Mean systolic pressures, but not mean diastolic pressures, in the upper arm and forearm differed significantly (t = 2.07, P = .04). A Bland-Altman analysis indicated that the distances between the mean values and the limits of agreement for the 2 sites ranged from 15 mm Hg (mean arterial pressure) to 18.4 mm Hg (systolic pressure).
  
  
  CONCLUSIONS
  Despite strict attention to correct cuff size and placement of the upper arm or forearm at heart level, measurements of blood pressure obtained noninvasively in the arm and forearm of seated patients in stable condition are not interchangeable.
authors.affiliation: Department of Nursing, University of Delaware, Newark, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Schell
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bradley
authors.forename: Linda
authors.initials: L
authors.lastname: Bucher
authors.forename: Maureen
authors.initials: M
authors.lastname: Seckel
authors.forename: Denise
authors.initials: D
authors.lastname: Lyons
authors.forename: Sandra
authors.initials: S
authors.lastname: Wakai
authors.forename: Deborah
authors.initials: D
authors.lastname: Bartell
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Carson
authors.forename: Melanie
authors.initials: M
authors.lastname: Chichester
authors.forename: Teresa
authors.initials: T
authors.lastname: Foraker
authors.forename: Kathleen
authors.initials: K
authors.lastname: Simpson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001132:Arm; D001331:Automation; D001795:Blood Pressure Determination / Q000295:instrumentation / Q000379:methods*; D002648:Child; D003691:Delaware; D004636:Emergency Service, Hospital; D005542:Forearm; D006801:Humans; D008297:Male; D008875:Middle Aged