hypothermia

Q: Effect of hypothermia on platelet dysfunction starts at what temperature?

A) 36°C
B) 34°C 
C) 32°C 
D) 30°C 


Answer: B

Hypothermia induces thrombocytopathy via two mechanisms. Primarily, hypothermia reduces the enzymatic activity of plasma coagulation proteins. Secondarily, by preventing the activation of platelets via traction on the glycoprotein Ib/IX/V complex by von Willebrand factor. The onset of this effect is seen as core temperatures drops to 34°C.

#hematology


Reference:

Kermode JC, Zheng Q, Milner EP. Marked temperature dependence of the platelet calcium signal induced by human von Willebrand factor. Blood 1999; 94:199. 

Jurkovich GJ, Greiser WB, Luterman A, Curreri PW. Hypothermia in trauma victims: an ominous predictor of survival. J Trauma 1987; 27:1019.