Inter-arm difference in blood pressure is something I vaguely remember learning about during a lecture on vascular disease, but it didn’t have the neurochemical clout to actually create a proper memory on account of the fact that, half way through, I either dozed off or buggered off (to play table football in the mess bar – I wouldn’t want you to think I was wasting my time).
Anyway, I’ve sort, of kind, of been hazily aware of it as a nebulous concept for, ooh, I don’t know, 27-odd years now, without it ever troubling my clinical consciousness or affecting my day job. Until today. Because I’ve just discovered that I should be ‘aggressively’ treating patients with an arm BP discrepancy of 10mmHg or more. Aggressively treating them for what? Raised cardiovascular risk. Apparently, this here arm discrepancy is yet another CV harbinger of doom, just like PAD, ED, creased ear lobes etc etc.
Oo-err missus. Maybe I should have paid more attention all those years ago. On the other hand, maybe you can reassure me that I’m not alone in never, ever checking the BP in both arms. Go, you don’t, do you? You can tell me. I won’t let on. It’ll just be between you, me, and the other 20,000-odd users of this site.
The big question is, can I be arsed to start doing it now? And the honest answer is, I don’t think so. I take the blood pressure from the patient’s right arm as that’s the one nearest my machine. To check the other am would involve some unseemly stretching and contortion with the attendant danger of BP machine, or me, or both, falling in the patient’s lap. And I think all parties would agree that risking a future infarct or cerebrovascular event is a small price to pay for avoiding that particular pratfall.
Of course, if you now start taking BPs bilaterally then you’ll unilaterally screw up the Bolam principle that keeps the rest of us who favour the one-arm approach medicolgeally watertight. I just hope you can sleep at night.