Occasionally, the forearm is used as an alternate site for blood pressure measurement (BPM), but the assumption has always
been the forearm reads higher than the upper arm. To determine the relationship, nurses recruited 106 participants from an
apartment complex in the Midwest. A variety of demographics were recorded, but the age range of 20 to 85 years turned out
to be significant.
Overall, the mean difference between the upper arm and forearm BPMs was modest (4.3 mm Hg systolic, 2.4 mm Hg diastolic),
however the range for the group was large (–44 mm Hg to 51 mm Hg systolic, –23.5 to 28.0 mm Hg diastolic). The largest systolic
mean difference was 10.7 mm Hg, found in those ages 36 to 50. The largest diastolic mean difference was 5.0 mm Hg, in the
age group of 51 to 65. Surprisingly, BPMs of those older than 66 had small mean differences of 0.2 mm Hg systolic and–3 mm
Hg diastolic.
In addition, obese adults with a BMI greater than 30, who are more likely to have their BPMs taken on the forearm when the
standard cuff size does not fit the upper arm, have the greatest difference between upper arm and forearm BPMs.
The difference between the two sites is largest for men due to obesity, all obese adults, and adults 51 to 65 years old.Noting which populations have the greatest difference between upper arm and forearm BPMs may aid the clinician in interpreting
clinical data and making decisions about the diagnosis and treatment of hypertension. Charting the patient's BPM location
helps the nursing team keep accurate results.
Domiano, K. L., Hinck, S. M., & et al. (2008). Comparison of Upper Arm and Forearm Blood Pressure. Clinical Nursing Research,
17(4), 241-250.
Staff Editor: MARTHA K. RAYMOND, RN, BSN, BS
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