The effect of temperature and pH on the activity of factor VIIa: implications for the efficacy of high-dose factor VIIa in hypothermic and acidotic patients.
J Trauma
; 55(5): 886-91, 2003 Nov.
Article
en En
| MEDLINE
| ID: mdl-14608161
ABSTRACT
BACKGROUND:
Recombinant coagulation factor VIIa (FVIIa) is approved for treating hemophiliacs with inhibitors. High-dose FVIIa has also been used off-label to manage hemorrhage in trauma and surgical patients, many of whom also develop hypothermia and acidosis.METHODS:
We examined the activity of FVIIa on phospholipid vesicles in the presence and absence of tissue factor (TF) and on platelets as a function of temperature and pH.RESULTS:
FVIIa activity on phospholipids and platelets was not reduced at 33 degrees C compared with 37 degrees C. The activity of FVIIa/TF was reduced by 20% at 33 degrees C compared with 37 degrees C. A pH decrease from 7.4 to 7.0 reduced the activity of FVIIa by over 90% and FVIIa/TF by over 60%.CONCLUSION:
FVIIa should be effective in enhancing hemostasis in hypothermic patients. However, because the activity of FVIIa is so dramatically affected by pH, its efficacy may be reduced in acidotic patients.
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Banco de datos:
MEDLINE
Asunto principal:
Acidosis
/
Plaquetas
/
Tromboplastina
/
Factor VIIa
/
Hipotermia
Límite:
Adult
/
Humans
/
Middle aged
Idioma:
En
Revista:
J Trauma
Año:
2003
Tipo del documento:
Article
País de afiliación:
Estados Unidos