Blood Pressure Measurement in Morbid Obesity: Comparison between Forearm and Intra-Arterial Assessment of Blood pressure

Abstract

Background: Obesity is associated with high blood pressure. Measurement of blood pressure (BP) in morbid obesity with a larger cuff bladder may be erroneous due to the anatomy of their upper limb and/or a nonsuitable cuff bladder. The objective of the study was to compare a non-invasive technique of BP measurement on the forearm with an appropriate standard blood cuff bladder to an invasive method (intra-arterial measurement in the radial artery) in two groups of subjects; non obese (NO) and morbidly obese (MO). 
 
 Methods: Twenty-seven NO subjects with a mean body mass index (BMI) of 25,6 ± 2,7 kg/m2 were evaluated using two different techniques for blood pressure measurement. Measures were performed, in a supine position, at the forearm level with a standard cuff bladder (Welch Allyn, NY, USA) and on the opposite forearm using an intra-arterial access. The NO group was compared to 20 MO subjects with a mean BMI of 5,1 ± 8,7 kg/m2. The MO group was evaluated during a bariatric surgery procedure, with regular intervals (10 to 15 min) using the same two methods described above.
 
 Results: A difference was observed between the two techniques of blood pressure measurements (P < 0.05 and P < 0.01 intra-arterial vs. cuff bladder for the NO and the MO groups respectively) (see Table). Correlations between the two techniques were observed in the NO group (P < 0.001) for the systolic BP (r=0,823) and the diastolic BP (r=0,769). Similar correlations were also observed in the MO group for the systolic BP (r=0,792, P < 0,001) and the diastolic BP (r=0,830, P < 0,001; Table).
 
 *** Table in Full Text PDF. ***
 
 Conclusion: Although different, BP measurements at the forearm level in MO subjects seems to be clinically valid. This technique may be used in this specific population as an alternative for the measurement of BP.