In vitro evaluation of the effect of hypothermia on coagulation in dogs via thromboelastography

Objective - To evaluate the effect of temperature alterations on in vitro coagulation in healthy dogs using thromboelastography (TEG). Design - In vitro study. Setting - University teaching hospital. Animals - Six healthy purpose-bred laboratory dogs. Interventions - None. Measurements and Main Results - Thromboelastograph tracings were created daily for all test subjects and used to generate control values for R, K, alpha, and MA. Control values were compared to test samples incubated at 42, 39, 36, 33, 30, and 27 degrees C. At temperatures <= 30 degrees C, a significant increase in K values and a significant decrease in the alpha values were noted. There were no significant differences detected for R and MA among any of the test temperatures. Conclusions - Hypothermia results in in vitro coagulation changes in healthy dogs as determined by whole blood analysis using TEG. The data suggest that while clots may form more slowly at decreased temperatures, the ultimate strength of the clot appears unaffected.