Publication: | 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 | ||
Reference: | Meng ZH, Wolberg AS, Monroe DM, 3rd, Hoffman M. 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. The Journal of trauma. 2003 Nov;55(5):886-91 | ||
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. | ||
Publication Type: | None | ||
Risk of Bias Score: | None |