If a cuff sized for a small child is used on an adult, what is the expected effect on the measured pressures?

If a cuff sized for a small child is used on an adult, what is the expected effect on the measured pressures?

• A. Both systolic and diastolic pressures would be higher than the true values
• B. Both systolic and diastolic pressures would be lower than the true values
• C. Only systolic pressure would be higher
• D. No change in measured pressures

Answer: (A)

Using a cuff that is too small on an adult causes the reading to be artificially elevated. A small cuff must be inflated to higher pressures to occlude the brachial artery, so the device records higher values for both systolic and diastolic pressures than the true values. In other words, the mis-sized cuff overestimates the blood pressure. If the cuff were too large, readings could be falsely low, but with a small child-sized cuff on an adult, both pressures go up.

Using a cuff that is too small on an adult causes the reading to be artificially elevated. A small cuff must be inflated to higher pressures to occlude the brachial artery, so the device records higher values for both systolic and diastolic pressures than the true values. In other words, the mis-sized cuff overestimates the blood pressure. If the cuff were too large, readings could be falsely low, but with a small child-sized cuff on an adult, both pressures go up.