Before taking blood pressure, what must you verify about the cuff?

• A. Use pediatric size cuff.
• B. Always use the largest cuff to ensure snug fit.
• C. Cuff size doesn't affect BP readings.
• D. Verify cuff size is appropriate for the patient arm.

Answer: (D)

Accurate blood pressure readings hinge on a cuff that fits the arm properly. Before measuring, verify that the cuff size is appropriate for the patient’s arm—width about 40% of the arm circumference and the bladder length roughly 80% of it—so the cuff encircles the arm adequately and sits level with the heart. A cuff that is too small will give falsely high readings, while a cuff that is too large can yield falsely low readings. Pediatric cuffs aren’t appropriate for most adults, and blindly using the largest cuff won’t guarantee accuracy. Checking and selecting the proper cuff size ensures the measurement is reliable.