dose of coagulation factor activity required in IU =
= ((target level of prothrombin complex as a percent from 0 to 100) - (current estimate of the prothrombin complex in percent)) * (body weight in kilograms)
where:
• The body weight is a surrogate marker for plasma volume.
• Each mL of plasma has about 1 IU of coagulation factor activity.
• The average volume of an FFP product is about 250 mL.
• A quick estimate for plasma volume in the adult (from Chapter 2) is 40 mL/kg in males and 36 mL/kg in females.
• An equation to calculate the prothrombin complex activity from the INR is available in section 04.05.02 .
volume of FFP required in mL =
= (dose of coagulation factor activity required in IU)
number of units of FFP to infuse =
= (volume of FFP required) / 250 mL
The number of units of FFP may be rounded up or down to the nearest integer.
In addition, a small dose of vitamin K may be administered.
