Taking blood pressure readings at the ankle, also known as blood pressure in the calf, is done when blood pressure cuffs are a poor fit for the size or shape of both arms and when blood pressure readings cannot be taken on either arm due to swelling, injury, surgery, graft, double mastectomy or amputation. Another need for ankle blood pressure measurement occurs with the possibility of peripheral vascular disease. To test for this condition, the doctor takes blood pressure readings on all four limbs, comparing the higher reading for the legs with the higher reading for the arms.
Select a blood pressure cuff of the proper size. The "bladder" of the cuff (the inflatable portion) should cover at least 80 per cent of the circumference of the leg.
Position the subject on her back, mention that you will return in 15 minutes and suggest that she relax during that time.
Bend the subject's leg at the knee, keeping the foot flat.
Close the cuff around the leg, with its lower edge about 1 inch above the protuberances on the inside and outside of the ankle, aligning the artery mark on the cuff above the artery in the ankle between the Achilles tendon and the inner ankle bone. Tighten the valve on the cuff so air won't escape. Make sure the gauge is in a position to be read easily.
Position the stethoscope ear pieces so they are angled forward in the ears. Feel for the pulse just below the lower edge of the cuff. Place the diaphragm of the stethoscope on this spot. Listen to the pulse.
Squeeze the bulb to inflate the cuff. Continue squeezing until the gauge reads 30mm of mercury (Hg) above the point at which the pulse could no longer be heard.
Open the blood pressure valve slowly so that pressure falls at a rate of about 2mm Hg per second.
At the first sound, take a reading---this is the systolic pressure. At the final sound, take another reading---this is the diastolic pressure. Open the valve completely.
When possible, get a medical professional to supervise anyone taking blood pressure readings for the first time. Subject should not have had alcohol or coffee within two hours of the blood pressure reading. Subject should not exercise, eat or take or use medications, including nasal decongestant sprays, within 30 minutes of the blood pressure reading. Subject should not have smoked within 15 minutes of the blood pressure reading. Ensure that clothing does not interfere with the blood pressure cuff.
Blood pressure cuffs should not be used on a leg with a deep vein thrombosis, graft, trauma, incision or swelling. Wait at least one minute before repeating the procedure. Subject and caregiver should avoid talking during the blood pressure reading. For some subjects, talking can result in an inaccurate high reading.