# A Sphygmomanometer reading can be correct only when :
A. Deflation is 5-10 mm Hg per heart beat
B. cuff is slightly full on applying to patient's arm
C. the cuff width is 25% of the diameter of the patient's arm
D. length of the bladder encircle 80% of the patient's arm
The correct answer is D. length of the bladder encircle 80% of the patient's arm.
Choosing appropriate sized cuff is vital to record accurate blood pressure in children. Small sized cuff gives elevated blood pressure readings and bigger sized cuffs give low blood pressure reading. The inflatable bladder inside the cuff should have an ideal width of at least 40% of the mid arm circumference and a cuff length that is 80 - 100% of the arm circumference.