Tourniquet pain: a volunteer study

The effect of inflation pressure (300 and 400 mm Hg) and method of exsanguination (gravity and Esmarch bandage) on the time of onset and the severity of tourniquet-induced pain in the lower extremity was investigated in 11 unmedicated adult volunteers. Each volunteer underwent eight experiments in a random order. A visual analog scale was used to assess pain and discomfort. Blood pressure and pulse rate were measured continuously. Experiments were concluded when the pain rose to a prefixed level. All experiments were performed using a standard orthopedic tourniquet (7 cm wide). Ten additional experiments were carried out using a Bier blockade tourniquet (5 cm wide). There were no differences in duration of tourniquet inflation between inflation pressures nor between methods of exsanguination. There was a small and transient but nevertheless statistically significant increase in blood pressure caused by inflation and a significantly larger increase just before deflation. The 5-cm tourniquet experiments, otherwise identical to the 7-cm tourniquet experiments, were tolerated significantly longer due to a longer time of onset and less severe pain. The 5-cm tourniquet also needed significantly higher inflation pressures to fully occlude the arterial supply (240-450 mm Hg). In all instances, 260 mm Hg was adequate to fully occlude the arterial supply when a 7-cm tourniquet was used. Only half of the experiments were concluded due to intolerable pain at the site of the tourniquet. Most of the others were concluded due to pain mainly in the calf or pain throughout the leg.(ABSTRACT TRUNCATED AT 250 WORDS)