Blood pressure assessment in severe obesity: Validation of a forearm approach

Abstract

Objective: Obesity is frequently associated with systemic hypertension. Blood pressure measure is inaccurate in severely obese patients because of poor cuff size fitting. Objective: The aim of the study is to assess the degree of agreement between the intra-arterial method as the gold standard vs. noninvasive methods, i.e., forearm blood pressure and upper-arm blood pressure measures. Design and Methods: A total of 1285 measures of intra-arterial and forearm blood pressure were taken in 51 severely obese patients in a supine position in the operating and the recovery room. A subset of 352 upper-arm measures were taken in the recovery room and compared to the intra-arterial and the forearm methods. Results: Correlation between the intra-arterial and the forearm measures was 0.90 (P < 0.001) for the 2570 data (systolic and diastolic). Compared to intra-arterial, the forearm method overestimated systolic (6 6 16 mm Hg, P < 0.001) and underestimated diastolic blood pressure (2 6 11 mm Hg, P 5 0.03). Compared to intra-arterial, upper-arm underestimated systolic (8 6 16 mm Hg, P < 0.01) and overestimated diastolic blood pressure (9 6 7 mm Hg, P < 0.001). Conclusion: The magnitude of differences between the intra-arterial and forearm method was less than differences between the intra-arterial and upper-arm method. Our results suggest that forearm method may be a more accurate alternative to upper-arm measurement to assess blood pressure in severely obese patients.

The impact of blood pressure cuff location on the accuracy of noninvasive blood pressure measurements in obese patients: an observational study

“…Recently, Leblanc et al 20 compared NIBP measurements obtained from the upper arm and forearm of morbidly obese patients with intra-arterial control measurements from the contralateral arm. The investigators found that the NIBP measurements from both the upper arm and forearm locations resulted in SBP and DBP measurements that closely correlated with those obtained from the intra-arterial measurements.…”

Arm Circumference, Shape, and Length: How Interplaying Variables Affect Blood Pressure Measurement in Obese Persons

“…In 2 studies, 11,13 cuff types were compared (standard vs large, rigid cylindrical vs conical); in 3 studies, 4,17,21 blood pressure measurements obtained via direct intra-arterial vs ausculatory/oscillometric techniques were compared; and in 6 studies, [14][15][16][18][19][20] blood pressure measurements obtained from the upper arm versus the forearm were compared.…”

“…7,8,18 When assessing blood pressure at alternative locations, it is essential to recognize that blood pressure varies appreciably in different parts of the arterial system, with SBP increasing in more distal arteries and DBP decreasinig. 23 Thus, because measurements of blood pressure in the forearm generally yield overestimates of SBP, DBP, and mean arterial pressure (MAP) compared with the upper arm (reported variances, 2.3-27 mm Hg), 10,14,[19][20][21]24,25 it is important to decide what discrepancy is clinically acceptable. 10,14,20 As McFarlane 10 described, a difference of ±5 mm Hg (standard deviation ≤8 mm Hg) is the standard used by the International Standards Organization and manufacturers that test noninvasive devices for measuring blood pressure against mercury sphygmo manometers.…”

Blood Pressure and the Obese

“…In a majority of studies, recruiting young healthy adults and eliminating individual characteristics that might influence blood pressure measurements, such as known cardiac arrhythmias or unstable medical condition, controlled sample selection. [40][41][42][43][44] Pierin and colleagues, 42 Vinyoles and colleagues, 45 Schell and colleagues, 43,44,46,47 Domiano and colleagues, 48 and Leblanc and colleagues 49 reported participants classified as obese as defined by a BMI greater than 30 kg/m 2 ; however, only 1 study 49 reported participants classified as morbidly obese separately. In 2 studies 42,49 in which obesity was required for inclusion in the sample, comparison of the conclusions with individuals who are classified as normal weight is not attainable.…”