Blood pressure cuff sizes

Quick search of allnurses didn't give me an answer, most of them were "art line vs manual" or general not able to hear manuals, etc. So I give you the question, then the scenario. However, not my patient, so I don't know the precise deatils.

Wrong sized bp cuffs can give off readings, that's a given. But will the wrong size give relatively correct readings.

Situation: Gen Med pt's blood pressure with the same cuff he's had on since down in the ed, had been giving a sbp in the mid 80's, over a few hours we watched it get to the 60's, calling the doc and finally called our rapid response team. They put a smaller cuff on the guy and got a sbp mid 80's. My concern is that even though the new, smaller cuff gave a "better" reading, could we still assume he had a ~20pt drop? (I say better because 80 is one of our criteria for calling rapid response team).
Gotta bust out the manual. When in doubt...

A really complex question, not a simple "was it a 20 point drop." No one should get to focused on the monitor or any one number. I know it wasn't your patient but a nurse needs to assess the whole picture. Was the patient maintaining his baseline level of altertness and orientation? Or was he becoming more lethargic? Any time a machine is showing changes in the patient's health LOOK AT THE PATIENT, and also look at the equipment. Yes too large a blood pressure cuff will give an inaccurate reading. I don't know if it was technically a "20 point drop." It is better to call the rapid response team in error than have the patient "crash."

Treat the patient, not the machine.

Good question, mine is always higher in the oncology office...and of course it could be the stress....but could it be because the cuff is to small....20 pts is alot...did calling the rapid response team do anything else that may have caused the change....including just the hub bub of haveing ten people entering your room wanting to do this that and the other to get a good assesment on him?

From my POV, since I take BPs every 5-10 minutes on ALL patients-the wrong size cuff CAN definitely give you problem BPs...anything from BPs indicating hypotension or hypertension....when in doubt...double check different extremities and CHANGE the cuffs...

just to be picky, even though we don't use mercury BP sphygs any-more, Blood pressure is still reported in mmHg. So it is not a "points" drop but mmHg drop. Sorry pet peeve!