USE OF A PNEUMATIC TOURNIQUET - INDUCES CHANGES IN CENTRAL TEMPERATURE

Twenty-six patients requiring orthopaedic surgery were anaesthetized a nd oesophageal and rectal temperature were monitored continuously. Twe nty patients requiring a pneumatic tourniquet were allocated prospecti vely to one of two groups: passive group (Pg) with reflective insulati on on all available skin surface (n=10) and forced group (Fg), with ac tive warming by a forced air system (n=10). Six patients without a tou rniquet were used as a reference group (Rg). The pneumatic tourniquet time was similar in the tourniquet groups. During tourniquet inflation , oesophageal temperature increased with time. The difference was sign ificant compared with the reference group at approximately 20 min. At about 30 min, oesophageal temperature in group Fg was significantly hi gher than that in group Pg. After tourniquet deflation, temperature de creased transiently. Changes in rectal temperature were similar but de layed significantly. A mechanism to explain the increase in core tempe rature during pneumatic tourniquet use remains unclear. A redistributi on mechanism by cooling of the blood in a cold and vasodilated limb co uld explain the decrease of temperature after tourniquet deflation.