Calculate precise cryoprecipitate requirements for bleeding disorders using plasma volume-based formulas. For transfusion specialists, hematologists, and critical care teams managing fibrinogen deficiency.
Use these validated formulas to determine cryoprecipitate dosing for active bleeding, DIC, or surgical prophylaxis:
✅ Fibrinogen Replacement Formula:
Required Units =
(Target Fibrinogen – Current Fibrinogen) × Plasma Volume
Fibrinogen Content per Unit
Key Components:
• Target Fibrinogen: Desired level (mg/dL)
• Current Fibrinogen: Measured level (mg/dL)
• Plasma Volume: In dL (deciliters)
• Fibrinogen/Unit: 150-250 mg (typically 200 mg)
• Current Fibrinogen: Measured level (mg/dL)
• Plasma Volume: In dL (deciliters)
• Fibrinogen/Unit: 150-250 mg (typically 200 mg)
Clinical Applications:
• Hypofibrinogenemia management
• Active bleeding with coagulopathy
• Perioperative prophylaxis
• DIC treatment protocols
• Active bleeding with coagulopathy
• Perioperative prophylaxis
• DIC treatment protocols
Plasma Volume Reference:
Plasma Volume (dL) = Weight (kg) × 0.07 × (1 – Hct) [Males]
= Weight (kg) × 0.065 × (1 – Hct) [Females]
Hct as fraction (e.g., 40% = 0.40)
= Weight (kg) × 0.065 × (1 – Hct) [Females]
Hct as fraction (e.g., 40% = 0.40)
Calculation Example:
70kg male, Hct 0.40:
Plasma Vol = 70 × 0.7 × (1-0.4) = 29.4 dL
Target: 150 mg/dL, Current: 80 mg/dL
Units = (150-80) × 29.4 ÷ 200
= (70 × 29.4) ÷ 200 ≈ 10.3 → 10-11 units
Plasma Vol = 70 × 0.7 × (1-0.4) = 29.4 dL
Target: 150 mg/dL, Current: 80 mg/dL
Units = (150-80) × 29.4 ÷ 200
= (70 × 29.4) ÷ 200 ≈ 10.3 → 10-11 units
Physiological Basis:
• Formula accounts for fibrinogen distribution
• Based on mass-balance principles
• Assumes immediate intravascular equilibration
• Plasma volume = distribution space
• Based on mass-balance principles
• Assumes immediate intravascular equilibration
• Plasma volume = distribution space
Special Considerations:
• Increase dose by 20-30% in active bleeding
• Use ideal weight for obese patients
• Consider consumption in DIC
• Check 1-hour post-transfusion levels
• Use ideal weight for obese patients
• Consider consumption in DIC
• Check 1-hour post-transfusion levels
Expected Response:
• 1 unit ≈ 5-10 mg/dL increase
• 10 units ≈ 50-100 mg/dL increase
• Refractoriness: <5 mg/dL per unit
• Half-life: 3-5 days
• 10 units ≈ 50-100 mg/dL increase
• Refractoriness: <5 mg/dL per unit
• Half-life: 3-5 days
Clinical Protocol:
1. Obtain current fibrinogen level
2. Calculate required increase
3. Determine plasma volume
4. Calculate units using formula
5. Administer cryoprecipitate
6. Check 1-hour post-transfusion level
2. Calculate required increase
3. Determine plasma volume
4. Calculate units using formula
5. Administer cryoprecipitate
6. Check 1-hour post-transfusion level
*Fibrinogen Content per Unit: 150-250 mg (average 200 mg used in calculations)
*Plasma Volume (dL) = Weight (kg) × Factor × (1 – Hematocrit) [Factor: 0.07 males, 0.065 females]
*Standard adult dose: 10 pooled units (contains ≈2000 mg fibrinogen)
*For 70kg adult: Expected increase ≈7-10 mg/dL per unit
*Critical threshold: <50-100 mg/dL requires urgent replacement
*Fibrinogen concentrate dose (mg) = (Target – Current) × Plasma Volume (dL)
*Plasma Volume (dL) = Weight (kg) × Factor × (1 – Hematocrit) [Factor: 0.07 males, 0.065 females]
*Standard adult dose: 10 pooled units (contains ≈2000 mg fibrinogen)
*For 70kg adult: Expected increase ≈7-10 mg/dL per unit
*Critical threshold: <50-100 mg/dL requires urgent replacement
*Fibrinogen concentrate dose (mg) = (Target – Current) × Plasma Volume (dL)
🧮 Cryoprecipitate Dose Calculator
📐 Formulas:
Required Units =
(Target Fibrinogen - Current Fibrinogen) × Plasma Volume
Fibrinogen Content per Unit
- Plasma Volume (dL):
Weight (kg) × 0.7 × (1 - Hematocrit) - Plasma Volume (mL):
Plasma Volume (dL) × 100 - Required Increase in Fibrinogen:
Target Fibrinogen − Current Fibrinogen - Total Dose Required:
Plasma Volume (dL) × Required Increase (mg/dL) - Cryoprecipitate Units Required:
Dose Required (mg) ÷ Fibrinogen per Unit (mg) - Estimated Fibrinogen Increase per Unit:
Fibrinogen per Unit (mg) ÷ Plasma Volume (dL)
💉 Enter the Values:
✅ Alternative Formulas (Most Useful):
Plasma Volume Calculator:
Plasma Volume (dL) =
Weight (kg) × 0.7 × (1 – Hematocrit)
Plasma Volume (mL) =
Plasma Volume (dL) × 100
Key Components:
• Weight: Actual body mass (kg)
• 0.7: TBV factor (dL/kg) for males
• Hematocrit: Fraction (0.0-1.0)
• Plasma Volume: Calculated volume
• 100: dL to mL conversion factor
• 0.7: TBV factor (dL/kg) for males
• Hematocrit: Fraction (0.0-1.0)
• Plasma Volume: Calculated volume
• 100: dL to mL conversion factor
Clinical Applications:
• Blood component dosing
• Pharmacokinetic calculations
• Therapeutic drug monitoring
• Transfusion medicine protocols
• Pharmacokinetic calculations
• Therapeutic drug monitoring
• Transfusion medicine protocols
Formula Derivation:
Total Blood Volume (dL) = Weight × 0.7
Plasma Fraction = 1 – Hematocrit
Plasma Volume (dL) = TBV × Plasma Fraction
Plasma Volume (mL) = Plasma Vol (dL) × 100
Plasma Fraction = 1 – Hematocrit
Plasma Volume (dL) = TBV × Plasma Fraction
Plasma Volume (mL) = Plasma Vol (dL) × 100
Calculation Example (Male):
70kg male, Hct 0.40:
PV (dL) = 70 × 0.7 × (1 – 0.40) = 29.4 dL
PV (mL) = 29.4 × 100 = 2940 mL
PV (dL) = 70 × 0.7 × (1 – 0.40) = 29.4 dL
PV (mL) = 29.4 × 100 = 2940 mL
Physiological Basis:
• 0.7 dL/kg = 70 mL/kg total blood volume
• Plasma fraction = 1 – Hct
• Standard TBV male: 70 mL/kg
• Standard TBV female: 65 mL/kg
• 1 dL = 100 mL
• Plasma fraction = 1 – Hct
• Standard TBV male: 70 mL/kg
• Standard TBV female: 65 mL/kg
• 1 dL = 100 mL
Special Considerations:
• Females: Use 0.65 factor
• Hct conversion: 45% = 0.45
• Obese patients: Use adjusted weight
• Pediatrics: Higher TBV factors
• Hct conversion: 45% = 0.45
• Obese patients: Use adjusted weight
• Pediatrics: Higher TBV factors
Clinical Example (Female):
60kg female, Hct 0.38:
PV (dL) = 60 × 0.65 × (1 – 0.38) = 24.18 dL
PV (mL) = 24.18 × 100 = 2418 mL
PV (dL) = 60 × 0.65 × (1 – 0.38) = 24.18 dL
PV (mL) = 24.18 × 100 = 2418 mL
Dosing Applications:
• Cryoprecipitate: Units = [Deficit (mg/dL) × PV (dL)] ÷ 150
• Fibrinogen: Dose (mg) = Deficit (mg/dL) × PV (dL)
• Plasma exchange: Volume = 1.0-1.5× PV (mL)
• Fibrinogen: Dose (mg) = Deficit (mg/dL) × PV (dL)
• Plasma exchange: Volume = 1.0-1.5× PV (mL)
Conversion Reference:
• 1 dL = 100 mL
• Hct percentage → fraction: ÷ 100
• TBV male: 0.7 dL/kg (70 mL/kg)
• TBV female: 0.65 dL/kg (65 mL/kg)
• PV (mL) = PV (dL) × 100
• Hct percentage → fraction: ÷ 100
• TBV male: 0.7 dL/kg (70 mL/kg)
• TBV female: 0.65 dL/kg (65 mL/kg)
• PV (mL) = PV (dL) × 100
Standard Volumes:
• Adult male PV: 25-45 dL
• Adult female PV: 20-40 dL
• 1 unit FFP ≈ 2-2.5 dL
• Therapeutic exchange: 35-55 dL
• Adult female PV: 20-40 dL
• 1 unit FFP ≈ 2-2.5 dL
• Therapeutic exchange: 35-55 dL
*Factor 0.7 = adult male TBV (70 mL/kg); use 0.65 for females (65 mL/kg)
*Hematocrit must be fraction (40% → 0.40)
*PV (mL) = PV (dL) × 100 = Weight × Factor × (1 – Hct) × 100
*For obese patients: Use adjusted body weight = IBW + 0.4×(Actual – IBW)
*Pediatric TBV: Neonates 85 mL/kg, Infants 80 mL/kg, Children 75 mL/kg
*Hematocrit must be fraction (40% → 0.40)
*PV (mL) = PV (dL) × 100 = Weight × Factor × (1 – Hct) × 100
*For obese patients: Use adjusted body weight = IBW + 0.4×(Actual – IBW)
*Pediatric TBV: Neonates 85 mL/kg, Infants 80 mL/kg, Children 75 mL/kg
Fibrinogen Replacement Calculator (All Formulas)
Required Increase (mg/dL) =
Target Fibrinogen – Current Fibrinogen
Total Dose (mg) =
Plasma Volume (dL) × Required Increase
Cryoprecipitate Units =
Total Dose (mg)
Fibrinogen per Unit (mg)
Increase per Unit (mg/dL) =
Fibrinogen per Unit (mg)
Plasma Volume (dL)
Key Parameters:
• Plasma Volume (dL): Weight × 0.7 × (1 – Hct) males
(0.65 for females)
• Fibrinogen/Unit: 150-250 mg (avg 200)
• Target Levels:
– General: >100 mg/dL
– Active bleeding: >150 mg/dL
– CNS surgery: >200 mg/dL
(0.65 for females)
• Fibrinogen/Unit: 150-250 mg (avg 200)
• Target Levels:
– General: >100 mg/dL
– Active bleeding: >150 mg/dL
– CNS surgery: >200 mg/dL
Clinical Protocol:
1. Measure current fibrinogen
2. Calculate required increase
3. Determine plasma volume
4. Calculate total fibrinogen dose
5. Convert to cryoprecipitate units
6. Verify expected increment
2. Calculate required increase
3. Determine plasma volume
4. Calculate total fibrinogen dose
5. Convert to cryoprecipitate units
6. Verify expected increment
Calculation Example:
70kg male, Hct 0.40, Current: 80 mg/dL → Target: 150 mg/dL
Plasma Vol (dL) = 70 × 0.7 × (1-0.4) = 29.4 dL
Required Increase = 150 – 80 = 70 mg/dL
Total Dose = 29.4 × 70 = 2058 mg
Units (200mg/unit) = 2058 ÷ 200 ≈ 10 units
Increase/Unit = 200 ÷ 29.4 ≈ 6.8 mg/dL
Expected rise: 10 × 6.8 = 68 mg/dL (→148 mg/dL)
Plasma Vol (dL) = 70 × 0.7 × (1-0.4) = 29.4 dL
Required Increase = 150 – 80 = 70 mg/dL
Total Dose = 29.4 × 70 = 2058 mg
Units (200mg/unit) = 2058 ÷ 200 ≈ 10 units
Increase/Unit = 200 ÷ 29.4 ≈ 6.8 mg/dL
Expected rise: 10 × 6.8 = 68 mg/dL (→148 mg/dL)
Physiological Principles:
• Fibrinogen distributes in plasma volume
• Formula assumes immediate equilibration
• Based on concentration = mass / volume
• Actual rise may be 20-30% lower due to:
– Ongoing consumption (DIC/bleeding)
– Extravascular distribution
– Laboratory variation
• Formula assumes immediate equilibration
• Based on concentration = mass / volume
• Actual rise may be 20-30% lower due to:
– Ongoing consumption (DIC/bleeding)
– Extravascular distribution
– Laboratory variation
Special Considerations:
• Active bleeding: Increase dose 20-30%
• DIC: Monitor consumption and repeat dosing
• Obese patients: Use adjusted body weight
• Refractoriness:
– CCI = [(Post-Pre) × BSA] ÷ Units
– Refractory if CCI < 4500
– Causes: Antibodies, splenomegaly, consumption
• DIC: Monitor consumption and repeat dosing
• Obese patients: Use adjusted body weight
• Refractoriness:
– CCI = [(Post-Pre) × BSA] ÷ Units
– Refractory if CCI < 4500
– Causes: Antibodies, splenomegaly, consumption
Product Information:
• Cryoprecipitate:
– 1 unit ≈ 150-250 mg fibrinogen
– Also contains Factor VIII, vWF, fibronectin
– Must be ABO compatible
• Fibrinogen Concentrate:
– Dose (mg) = Total Dose
– Purified, viral-inactivated
– No cross-matching required
– 1 unit ≈ 150-250 mg fibrinogen
– Also contains Factor VIII, vWF, fibronectin
– Must be ABO compatible
• Fibrinogen Concentrate:
– Dose (mg) = Total Dose
– Purified, viral-inactivated
– No cross-matching required
Monitoring Protocol:
• Check fibrinogen 1-hour post-transfusion
• Calculate observed increase
• Recovery = (Observed ÷ Predicted) × 100
• Investigate if recovery < 60-70%
• Monitor for transfusion reactions:
– TRALI, TACO, allergic reactions
– Citrate toxicity (paresthesia, arrhythmias)
• Calculate observed increase
• Recovery = (Observed ÷ Predicted) × 100
• Investigate if recovery < 60-70%
• Monitor for transfusion reactions:
– TRALI, TACO, allergic reactions
– Citrate toxicity (paresthesia, arrhythmias)
Clinical Pearls:
• 10 units cryo ≈ 50-100 mg/dL increase in adults
• Fibrinogen half-life: 3-5 days
• Critical threshold: <50-100 mg/dL requires replacement
• For major bleeding: Maintain >150-200 mg/dL
• Consider thrombotic risk with over-replacement
• Fibrinogen concentrate preferred for purified replacement
• Fibrinogen half-life: 3-5 days
• Critical threshold: <50-100 mg/dL requires replacement
• For major bleeding: Maintain >150-200 mg/dL
• Consider thrombotic risk with over-replacement
• Fibrinogen concentrate preferred for purified replacement
Key Formulas Reference:
• Plasma Volume (dL) = Weight (kg) × 0.07 × (1 – Hematocrit) [Male] | 0.065 [Female]
• Required Increase (mg/dL) = Target Fibrinogen – Current Fibrinogen
• Total Dose (mg) = Plasma Volume (dL) × Required Increase
• Cryoprecipitate Units = Total Dose (mg) ÷ Fibrinogen per Unit (mg)
• Increase per Unit (mg/dL) = Fibrinogen per Unit (mg) ÷ Plasma Volume (dL)
• Adjusted Body Weight (kg) = IBW + 0.4×(Actual – IBW) [For obese patients]
• Corrected Count Increment (CCI) = [(Post-Pre) × BSA (m²)] ÷ Units
• Plasma Volume (dL) = Weight (kg) × 0.07 × (1 – Hematocrit) [Male] | 0.065 [Female]
• Required Increase (mg/dL) = Target Fibrinogen – Current Fibrinogen
• Total Dose (mg) = Plasma Volume (dL) × Required Increase
• Cryoprecipitate Units = Total Dose (mg) ÷ Fibrinogen per Unit (mg)
• Increase per Unit (mg/dL) = Fibrinogen per Unit (mg) ÷ Plasma Volume (dL)
• Adjusted Body Weight (kg) = IBW + 0.4×(Actual – IBW) [For obese patients]
• Corrected Count Increment (CCI) = [(Post-Pre) × BSA (m²)] ÷ Units
Clinical Application Example
Scenario: 60 kg female with Hct 35%, current fibrinogen 60 mg/dL (postpartum hemorrhage), target 150 mg/dL.
- Plasma Volume (dL):
60 × 0.7 × (1 - 0.35) = 27.3 dL - Required Increase:
150 - 60 = 90 mg/dL - Total Dose:
27.3 × 90 = 2457 mg - Units Required (200 mg/unit):
2457 ÷ 200 = 12.3 → 13 units - Expected Rise per Unit:
200 ÷ 27.3 = 7.33 mg/dL - Total Expected Fibrinogen:
13 × 7.33 = 95.2 mg/dL
Clinical Guidelines & Adjustments
| Parameter | Standard | Special Populations |
|---|---|---|
| Fibrinogen/Unit | 200 mg (150-250 mg) | Verify with blood bank |
| Target Levels | ||
| – Active Bleeding | ≥150 mg/dL | Obstetrics: ≥200 mg/dL |
| – Prophylaxis | ≥100 mg/dL | DIC: Individualize |
| Hematocrit Input | Current Lab Value | Massive Transfusion: Use initial Hct |
Critical Safety Checks
✅ Before Transfusing:
- Confirm fibrinogen <100 mg/dL with active bleeding
- Use ABO-compatible units when feasible
- Pool units ≤4 hours before infusion
⚠️ Monitor For: - Transfusion-associated circulatory overload (TACO)
- Hypocalcemia (citrate toxicity)
- Thrombosis in thrombophilic states
Dosing Optimization Tips
- Refractory Bleeding:
- Repeat fibrinogen 30 min post-transfusion
- Additional dose =
[(Target - New Level) × Plasma Volume (dL)] / 200
- Pediatric Patients:
- Plasma Volume (dL) =
Weight (kg) × 0.8 × (1 - Hct) - Minidose: 1 unit/5 kg (max 4 units for neonates)
- Volume-Restricted Cases:
- Use fibrinogen concentrates if available
Applications:
- Obstetric hemorrhage
- Cardiovascular surgery
- Trauma-induced coagulopathy
Access Our Interactive Calculator:
Input weight, Hct, fibrinogen levels → Instant unit recommendations
Disclaimer: Clinical context supersedes calculations. Consult hematology for complex cases.
✅ Key Advantages:
- Hematocrit-adjusted plasma volume
- Realistic fibrinogen yield per unit
- Built-in safety rounding (whole units)
- Rise prediction for dose verification
