After inflating a blood pressure cuff from 10 mm Hg to 20 mm Hg over the patient's systolic blood pressure, the Trousseau sign is considered positive if carpal spasm develops, with flexion of the thumb and adduction of the finger within 3 minutes. However, this can be painful, so the time should be noted, and the cuff should be deflated once the test is positive. [from
HPO]