What is the impact of improper cuff sizing on BP measurement?

• A. It has no effect on accuracy
• B. It may improve accuracy
• C. It only affects diastolic readings
• D. It decreases accuracy

Answer: (D)

When measuring BP, the cuff size must match the arm to get an accurate reading. If the cuff is too small, it tends to overinflate the readings, making systolic and diastolic values appear higher than they really are. If the cuff is too large, it tends to underinflate the readings, producing lower values. Either way, the measurement is biased and not truly accurate. That’s why improper cuff sizing decreases accuracy. To minimize error, use a cuff with a bladder width about 40% of the arm circumference and a length that encircles about 80% of the arm.