Calculate FFP dosing by weight and indication for coagulopathy correction, warfarin reversal, massive transfusion, and plasma exchange protocols.
Fresh frozen plasma (FFP) is a blood product containing all coagulation factors, fibrinogen, and plasma proteins. It is prepared from whole blood donations and stored at -18°C or colder, maintaining coagulation factor activity for up to one year. FFP is the standard treatment for correcting coagulopathy from multiple factor deficiencies, urgent warfarin reversal when prothrombin complex concentrate is unavailable, and as replacement fluid during therapeutic plasma exchange.
Standard FFP dosing ranges from 10 to 20 mL/kg depending on the clinical indication and severity of coagulopathy. Each unit of FFP is approximately 200–300 mL (typically ~250 mL) and contains roughly 1 unit/mL of each coagulation factor. At a dose of 10–15 mL/kg, FFP raises coagulation factor levels by approximately 15–25%, sufficient to correct most mild-to-moderate coagulopathies. Higher doses of 15–20 mL/kg are used for severe bleeding, warfarin reversal, or massive transfusion protocols.
This FFP dose calculator computes the recommended volume and number of units based on patient weight and clinical indication, estimates the expected rise in coagulation factor levels, projects post-transfusion INR correction, and provides infusion time estimates. It includes dosing guidelines for all major FFP indications including DIC, TTP plasma exchange, liver disease coagulopathy, and massive transfusion protocols with the now-standard 1:1:1 ratio of PRBCs to FFP to platelets.
Calculating FFP doses by weight, converting to units, and estimating INR correction involves several steps that are easy to miscalculate during emergency situations. This calculator provides instant dose computation with indication-specific recommendations, unit count rounding, and reference tables that can be quickly consulted at the bedside or during massive transfusion protocol activation.
FFP dose (mL) = weight (kg) × dose (mL/kg). Number of units = total volume ÷ unit volume (rounded up). Estimated plasma volume = weight × 70 mL/kg × (1 - Hct/100). Factor increase (%) = (FFP volume ÷ plasma volume) × 100. INR correction estimate: post-INR ≈ pre-INR - (pre-INR - 1) × correction factor.
Result: 4 units FFP (1,000 mL) at 15 mL/kg
A 70 kg patient for warfarin reversal: 70 × 15 = 1,050 mL → 4 units (1,000 mL actual). Estimated plasma volume: 70 × 70 × 0.62 = 3,038 mL. Expected factor increase: ~33%. Estimated post-transfusion INR: approximately 1.8–2.0.
Each unit of FFP contains all coagulation factors at approximately 1 IU/mL, including Factors II, V, VII, VIII, IX, X, XI, XII, XIII, von Willebrand factor, fibrinogen (2–4 mg/mL), protein C, protein S, and antithrombin. FFP is stored at -18°C or below and has a shelf life of 12 months. Once thawed, it should be used within 24 hours (as "thawed plasma") or within 5 days if relabeled and stored at 1–6°C, though Factor V and Factor VIII activity decline significantly after thawing.
The most evidence-supported indications for FFP are (1) urgent reversal of vitamin K antagonists when PCC is unavailable, (2) correction of multiple clotting factor deficiencies with active bleeding, (3) as replacement fluid in therapeutic plasma exchange for TTP, and (4) massive transfusion protocols. The use of FFP to correct mildly elevated INR (< 1.8) without bleeding is controversial and generally not recommended, as the coagulation factor content of FFP may be insufficient to normalize INR from near-normal levels.
Four-factor PCC (Kcentra, Beriplex) has largely replaced FFP for urgent warfarin reversal in hospitals where it is available. PCC contains concentrated Factors II, VII, IX, and X with protein C and S, and provides faster, more predictable INR correction in much smaller volumes (typically 25–50 mL vs. 1,000+ mL for FFP). Cryoprecipitate is preferred when fibrinogen replacement is the primary goal. Recombinant Factor VIIa may be used for specific refractory hemorrhage scenarios but is expensive and carries thrombotic risk.
The standard dose is 10–15 mL/kg for most indications. For warfarin reversal, 15–20 mL/kg is recommended. For TTP/plasma exchange, one plasma volume (~40 mL/kg) is exchanged. Each unit is approximately 250 mL.
FFP should be infused within 4 hours of thawing and at a rate the patient tolerates — typically 200–250 mL over 30 minutes in adults. Faster rates may be necessary for active hemorrhage. Monitor for transfusion reactions throughout.
Yes, FFP should be ABO-compatible. Group AB plasma is the universal donor plasma since it contains no anti-A or anti-B antibodies. Group-specific plasma is preferred when available. Rh compatibility is not required for FFP.
Four-factor prothrombin complex concentrate (PCC) is preferred over FFP for urgent warfarin reversal when available. PCC provides faster and more reliable INR correction in smaller volumes (25–50 units/kg), without the volume overload risk of large-volume FFP transfusion.
The duration of FFP effect depends on the half-lives of the replaced coagulation factors. Factor VII has the shortest half-life (~6 hours), so INR may begin rising again within 6–12 hours. Repeat dosing or addressing the underlying cause is often necessary.
Risks include transfusion-related acute lung injury (TRALI), transfusion-associated circulatory overload (TACO), allergic reactions, febrile non-hemolytic reactions, and rarely infection transmission. Volume overload is a particular concern — 4 units of FFP add approximately 1 liter of volume.