BP from legs

Q; Lower extremity blood pressure measurement is usually _________ than upper extremity blood pressure? 

A) higher

B) lower

Answer: A

It is a common scenario in ICU when nursing staff has to rely on blood pressure (BP) measurement from lower extremities, particularly in patients with vascular fistulae or grafts. By default, the systolic pressure (SBP) in legs is usually higher than that in the arms (brachial artery). The difference on an average is by about 10 mmHg in the calf. It is even higher in the ankle by 17 mmHg. 

This does not apply to people with peripheral vascular disease (PVD) who usually have SBP lower at the ankle than the arm. Also, it is important that proper cuff size is applied.

#hemodynamics

References:

1. Measurement of Blood Pressure: Taking Blood Pressure in the Thigh. In: Kaplan's Clinical Hypertension, Kaplan NM, Victor RG (Eds).

2. Sheppard JP, Albasri A, Franssen M, et al. Defining the relationship between arm and leg blood pressure readings: a systematic review and meta-analysis. J Hypertens 2019; 37:660.

3. Allison MA, Hiatt WR, Hirsch AT, et al. A high ankle-brachial index is associated with increased cardiovascular disease morbidity and lower quality of life. J Am Coll Cardiol 2008; 51:1292.