Fresh Frozen Plasma Dosing
The recommended initial dose of fresh frozen plasma (FFP) is 10-15 ml/kg body weight, which typically translates to 2-4 units (500-1000 ml) for an average 70 kg adult. 1, 2
Standard Dosing Protocol
Initial Dose
- Administer 10-15 ml/kg as the standard initial dose for correction of coagulopathy with active bleeding 1, 2
- This dose is calculated to achieve a minimum of 30% plasma factor concentration, which is the threshold needed for effective hemostasis 1
- Each unit of FFP contains approximately 250-300 ml, so most adults will require 2-4 units initially 2
Dose-Response Relationship
- Doses below 10 ml/kg are inadequate and unlikely to correct coagulopathy effectively 1, 2
- Research demonstrates that median doses of 17 ml/kg successfully corrected INR in coagulopathic patients, while 10 ml/kg doses failed to do so 3
- Higher doses (8 ml/kg vs 4 ml/kg) show significantly better response rates in correcting coagulopathy 2
Clinical Indications for FFP Administration
Primary Indications
- Active microvascular bleeding with PT >1.5 times normal, INR >2.0, or aPTT >2 times normal 1
- Massive transfusion scenarios (>1 blood volume or ~70 ml/kg) with ongoing bleeding when coagulation tests cannot be obtained timely 1
- Correction of known coagulation factor deficiencies when specific concentrates are unavailable 1
- Heparin resistance due to antithrombin III deficiency in patients requiring heparin 1
Special Dosing Situations
Urgent Warfarin Reversal:
- Use lower doses of 5-8 ml/kg (approximately 1-2 units for most adults) 1, 2
- However, prothrombin complex concentrate (PCC) is strongly preferred over FFP for this indication when available, as it provides faster and more complete INR correction 1, 4
- In the INCH trial, PCC achieved INR ≤1.2 in 67% of patients versus only 9% with FFP, and was associated with less haematoma expansion in intracranial hemorrhage 4
Monitoring and Repeat Dosing
Assessment After Initial Dose
- Recheck coagulation parameters (PT/INR, aPTT) after transfusion to determine need for additional doses 2
- Only 36% of patients achieve INR correction with initial FFP dosing, necessitating repeat assessment 3
- Further doses may be required based on ongoing bleeding and laboratory values 1
Factors Affecting Response
- There is marked variability in individual patient response to FFP 5
- Hemostatic benefits are confined to patients with documented coagulopathy; prophylactic FFP in non-bleeding patients with mild coagulopathy does not prevent bleeding and increases complications 2
Critical Safety Considerations
Major Risks
- Transfusion-related acute lung injury (TRALI) is the most serious complication, with FFP being one of the most frequently implicated blood products 1, 2
- In one study, new-onset acute lung injury occurred in 18% of transfused patients versus 4% of non-transfused patients 3
- Other risks include circulatory overload, ABO incompatibility, infectious disease transmission, and allergic reactions 1, 2
Contraindications and Inappropriate Uses
- FFP is NOT indicated for volume expansion or albumin replacement 1, 2
- Do not use FFP when PT, INR, and aPTT are normal 1
- Avoid FFP for correcting coagulation deficiencies in cirrhotic patients without active bleeding, as it may significantly increase portal pressure 2
- Do not use prophylactically for mild-moderate coagulation abnormalities before invasive procedures in non-bleeding critically ill patients 2
Practical Administration Details
Preparation and Timing
- FFP can be thawed using dry oven (10 minutes), microwave (2-3 minutes), or water bath (20 minutes) 2
- Once thawed, FFP remains usable for up to 24 hours if stored at 4°C 2
- FFP must be ABO-compatible with the patient (use AB if blood type unknown) 2
Massive Transfusion Context
- In trauma resuscitation, FFP:PRBC ratios of 1:2 to 3:4 appear optimal, with maximal hemostatic effect observed at these ratios 5
- Ratios ≥1:1 do not confer additional hemostatic advantage over 1:2 to 3:4 ratios and may increase complications 5
- Four to five platelet concentrates or one unit of single-donor apheresis platelets provide coagulation factors equivalent to one unit of FFP 1
Alternative Therapies to Consider
- For hypofibrinogenemia (fibrinogen <80-100 mg/dl), cryoprecipitate is more effective than FFP 2
- For urgent anticoagulation reversal, prothrombin complex concentrate is superior to FFP in both efficacy and safety 1, 2, 4
- For specific factor deficiencies, targeted factor concentrates should be used when available rather than FFP 1