Corrected entry: When Hawkeye takes Lt. Hoolihan's blood pressure, he attaches the cuff below her elbow. Blood pressure cuffs must go above the elbow.
Correction: Technically, that is correct. The real error is that the cuffs use Velcro, which wasn't invented till well after Korean War.
Correction: I haven't seen the episode, but a blood pressure cuff does not need to be above the elbow, it just needs to be over an artery, any artery close enough to the surface to get a reading. Often, if the arms are too large, or if there are problems with the upper arm, a cuff may be placed below the elbow, around the wrist, even on legs if there is no other place, though that doesn't happen very often.
Nikki