Alterations in hemostasis associated with hyperthermia in a canine model

Use of hyperthermia in the treatment of cancer and viral infection has rece ived renewed interest. However, the in vivo relationship between hypertherm ia and direct Versus indirect effects upon hemostasis are incompletely defi ned, although we do know that disseminated intravascular coagulation (DIC) is a common sequel to heat stroke. The purpose of the present study was to more precisely define the relationship between hyperthermia and derangement s of hemostasis, thereby providing a guideline for the development of safe hyperthermia treatment regimens. The present investigation examined the in vivo effects of high-grade whole-body hyperthermia (WBH) (42.5 degrees C, 9 0 min) on hemostasis in a canine model. Induction of hyperthermia via extra corporeal circulation of heated blood (ECC-WBH) caused thrombocytopenia, in creased plasma fibrin degradation products (FDPs), prolonged clotting times , increased serum liver enzymes, and evidence of spontaneous bleeding. Howe ver, when WBH was induced by peritoneal lavage (PL-WBH), transient thromboc ytopenia was the only significant alteration. Temporal correlation between hemostatic alterations and elevations in serum alanine aminotransferase (AL T) levels in the ECC-WBH treatment group suggested that liver injury is res ponsible, at least in part, for the coagulopathy associated with high-grade hyperthermia and that. in the absence of liver injury, identical degrees o f hyperthermia cause only incidental decreases in platelet numbers. Am. J, Hematol., 64:262-270, 2000. (C) 2000 Wiley-Liss, Inc.