Routine monitoring of blood pressure (BP) in an extremity with an arteriovenous (AV) access is contraindicated due to concern that it can cause access site thrombosis. According to the Intersocietal Accreditation Commission (IAC) guidelines do not specify BP measurement in evaluation of steal. Ultra-sonographers tend to avoid BP measurement over the AV access because it is not part of a universal protocol and patients have trepidation that access will fail. Taking BP in both arms is a very helpful diagnostic tool in evaluation of steal syndrome. This study investigates the safety of taking blood pressure over an AV access as part of a diagnostic study.
This retrospective cohort study evaluates the patency of upper extremity AV access after bilateral blood pressure measurement in patients receiving regular dialysis. Between 10/2015-9/2019, 282 patients were tested for AV steal, which included AV access scan, upper arm blood pressure measurement, and a photoplethysmography test. A chart review was used to determine if fistula/graft remained patent.
Of the 282 patients, 83 were removed from the study due to failure to have blood pressures taken from both arms (n=48) or insufficient documentation (n=35). Among the remaining 199 patients no acute access thrombosis or early AV access failure occurred after taking blood pressures on both arms. Systolic blood pressure difference of greater than 20mmHg between the two arms was registered in 63 patients (31.66%). Based on the completed diagnostic tests 19 patients (9.5%) went under angiogram as further diagnostic testing, and 9 cases (4.5%) had ligation.
Based on our findings, measuring bilateral blood pressure on upper extremities with active AV access has minimal risk and is an important diagnostic tool in the assessment of AV steal. The IAC may want to consider amending their guidelines.
Cara Chasin, Post Doc Research Fellow/ MD, Houston Methodist Hospital