THE COAGULOPATHY OF HEAT-STROKE ALTERATIONS IN COAGULATION AND FIBRINOLYSIS IN HEAT-STROKE PATIENTS DURING THE PILGRIMAGE (HAJJ) TO MAKKAH

Haemostatic measurements were undertaken in 132 patients diagnosed wit h heat stroke during the pilgrimage to Makkah, in two successive summe rs of 1989-90. The control group comprised 49 patients, all pilgrims, with a wide range of clinical conditions, but without hyperpyrexia or deranged haemostasis. Heat stroke patients showed (i) significant prol ongation of the prothrombin (PT), activated partial thromboplastin (aP TT) and thrombin times (TT) but normal reptilase time (RT); (ii) signi ficant reduction in plasma levels of antithrombin III (AT-III), factor V, proteins C and S, plasminogen activator inhibitor (PAI) and platel et count; (iii) increase in plasma factor VIII, tissue plasminogen act ivator (t-PA) and serum FDP; (iv) no significant changes in plasma fib rinogen, plasminogen, alpha(2)-antiplasmin and factors VII and X. Heat stroke patients were then grouped into those with and those without b leeding symptoms. Bleeders showed greater prolongation of the PT, aPTT and TT and significant reductions in fibrinogen, AT-III, factors V, V III and X, plasminogen, alpha(2)-antiplasmin and platelet count. Logis tic regression and discriminant analysis showed that AT-III was the pa rameter associated most with heat stroke and reliable enough to predic t its occurrence, whether or not bleeding occurred. The results indica te that activation of the haemostatic mechanism, consumptive in nature , regularly accompanies heat stroke and highlights the physiological r ole of AT-III in checking this activation process.