I had a call today that had a few complicating factors, but the one that really threw me was that the pt had a fistula, which we didn't discover until partway through the call. The chief complaint was hypoglycemia and we were getting obviously erroneous BGL readings. After we switched the the hand on the non-fistula side, we got good numbers. Obviously, not a problem to just switch sides, but I was surprised that the fistula seems to have thrown the assessment off in the first place. I get the problem with taking BP on that side, but the glucose level should be the same throughout the periphery, correct? Was this our equipment being wonky or am I misunderstanding how fistulas affect circulation.