Procedures under tourniquet

Abstract

The pneumatic tourniquet is used widely in operations involving the limbs. However, despite its everyday use, a clinician's knowledge of this instrument is often confined to the pressure and time limits. Although the principle behind the tourniquet is simple, anaesthetists and surgeons should appreciate the effects of the tourniquet as well as the various complications associated with its use. Safe use of the tourniquet starts from the point of setting up the pneumatic machine. It is important to choose the appropriate pressure. Over inflation can lead to nerve damage and under inflation will lead to a bloody surgical field and unnecessary blood loss. The tourniquet should be applied with care to avoid local damage to the skin. Pathophysiological effects of the tourniquet can range from a simple tachycardia and increase in systolic pressure to fatal events, such as large pulmonary embolus and cardiac arrest. Prolonged use of the tourniquet can lead to a phenomenon known as tourniquet pain. Other complications associated with the use of the tourniquet include nerve and vascular damage and muscle contracture. In the past, the tourniquet was not used in patients with sickle cell disease to avoid triggering a sickle cell crisis. However, when the optimum conditions are created (sufficient hydration, good oxygenation, warmth and mild hyperventilation) it can be used successfully in this group of patients, who should not be deprived of the choice of having their limb operations with a tourniquet.