Squeeze Smart: Match the Correct Cuff to the Correct Arm

Background: Cuff and bladder design is crucial when taking blood pressure (BP) measurements in patients with larger arms, especially when the arm circumference near the shoulder exceeds that near the elbow resulting in a conical-shaped arm often seen in obese patients. Traditional cylindrical cuffs expand unevenly on conical upper arms overestimating BP values by up to 15mmHg due to poor fit and improper compression of the brachial artery. The lack of tapering leads to uneven pressure distribution with higher pressure at the proximal arm and lower pressure at the distal arm. This results in overestimation of both systolic BP (sBP) and diastolic BP (dBP). The limited attention given to using suitable BP cuffs may be causing a falsely elevated prevalence of hypertension leading to unnecessary treatment with antihypertensive medications in this population. Methods: 50 adult patients with hypertension defined as BP above 130/80 and arm circumference greater than 37cm were selected for the study. These patients had BP taken with the standard cylindrical cuff and immediately had repeat BP taken with the trunco-conical cuff on the same arm. BP obtained from both cuffs were compared using a two-tailed paired t-test. Results: Mean sBP from cylindrical cuff was 157.72 with a SD of 16.69 compared to 135.74 with a SD of 11.98 for the trunco-conical cuff. Mean dBP from cylindrical cuff was 93.32 with a SD of 14.80 compared to 83.10 with a SD of 9.61 for the trunco-conical cuff. Analysis was done using the two tailed paired t-test and was conducted at the 0.05 significance level. Based on these results we can conclude that the mean difference in sBP (t = 12.15, df=49, p-value 2.11E-16) and the mean difference in dBP between the two cuffs (t = 6.00, df = 49, P-value = 2.36E-07) is statistically significant at this level. Conclusion: BP obtained from trunco-conical cuff was significantly different than that obtained from a standard cylindrical cuff in adult patients with arm circumferences greater than 37cm. This underscores the importance of using trunco-conical shaped BP cuffs specifically designed for patients with non-cylindrical arms to better address their unique anatomical shape. Future study already in process will compare BP obtained from trunco-conical cuffs to those obtained from arterial lines to determine accuracy of BP readings obtained from these cuffs.