The potential use of desmopressin to correct hypothermia-induced impairment of primary haemostasis--an in vitro study using PFA-100.

Objective: Mild hypothermia (32-35 degrees C) impairs primary haemostasis and coagulation. Correction of these haemostatic impairments by rewarming alone may not be possible or desirable, particularly in major trauma, neuroanaesthesia and in critically ill patients. Pharmacological treatment of these impairments, if available, may be a useful alternative. Desmopressin has been used to treat various congenital and acquired platelet disorders, but its effects on hypothermia-induced impairment of primary haemostasis is not known. This study aims to investigate the in vitro effects of desmopressin on hypothermia-induced impairment of primary haemostasis using PFA-100 platelet function analyzer.

Methods: Whole blood was collected from 20 healthy volunteers, divided into 2.7 ml aliquots and some incubated at 32 degrees C, and others at 37 degrees C as control. Three log doses of desmopressin (0.01, 0.1 or 1 nM) were added to aliquots at 32 degrees C, and saline was added to controls at both 32 and 37 degrees C, all in 0.1 ml volume. After incubating for 30 min, closure times (CT) was measured by PFA-100 using both collagen/epinephrine (adrenaline) (Col/EPI) and collagen/adenosine-5'-diphosphate (Col/ADP) cartridges.

Results: CT was prolonged by 30.9% (Col/EPI) and 18.8% (Col/ADP) at 32 degrees C, respectively, compared to 37 degrees C (P<0.001). All the three doses of desmopressin significantly, but incompletely corrected CT prolongation due to hypothermia (P<0.002).

Conclusion: Desmopressin partially reverses hypothermia-induced impairment of primary haemostasis in vitro, and may be potentially useful in improving haemostasis in hypothermic patients with bleeding where immediate rewarming is difficult or undesirable.