Prime Calculations

CO

CI x BSA

Full flow

2.4 LPM

DuBois BSA

height in cm^0.725 x weight in kg^0.425 × 0.007184

2.54

cm/in

2.2

lb/kg

peds full flow

2.6-3.0 LPM

0-10 kg patient blood volume

85 ml/kg

11-25 kg patient blood volume

80 ml/kg

26-45 kg patient blood volume

70 ml/kg

>45 kg patient blood volume

65 ml/kg

Patient hematocrit

Percentage of blood that is RBCs. Total red cell volume (RCV) / patient blood volume (PBV)

Patient blood volume (PBV)

Total red cell volume (RCV) + total plasma volume (TPV)

Plasma fraction (PF)

Portion of blood that is plasma. 1 - HCT

patient red cell volume (RCV)

HCT x patient blood volume (PBV)

patient plasma volume (PPV)

Portion of patient’s blood that is plasma. (1 - HCT) or PF x patient blood volume (PBV)

patient

All pre-bypass or pre-dilutional calculations. PBV, P-RCV, PPV

total

All post-dilutional calculations. TBV, T-RCV, TPV

Total blood volume (TBV)

Patient blood volume (PBV) + prime volume, all in mL

total plasma volume (TPV)

PPV ( or PF x PBV) + clear prime volume, all in mL

post-dilutional HCT

(Pre-bypass HCT x PBV) / TBV

post-dilutional platelet count

pre-bypass PLT x patient plasma volume (PPV) / total plasma volume (TPV).

post-dilutional fibrinogen

pre-bypass fibrinogen x patient plasma volume (PPV) / total plasma volume (TPV). Normal = 200-400 mg/dL

colloid osmotic pressure (COP)

Regulates fluid exchange between intravascular and interstitial spaces. Normal = 18-25 mmHg. Decrease causes edema

patient colloid osmotic pressure (COP)

(Total protein x 3.02) + 0.65. If TP is unavailable, we assume a normal value of 20 mmHg

post-dilutional colloid osmotic pressure (COP)

(pre-bypass COP x PPV) + (PV x constituent COP) / TPV. Constituents = any added non-plasma components like fibrinogen, FFP, albumin

adding PRBCs

(desired HCT x TBV) - (baseline HCT x PBV) / 0.60. Each unit has a HCT of 60% with 40% dilutants and plasma. Does not contribute to COP

increasing fibrinogen by adding fresh frozen plasma (FFP)

(desired fibrinogen x TPV) - (baseline fibrinogen x PPV) / 200. Each unit has 200mg/dL of fibrinogen.

increasing COP by adding FFP or albumin

(desired COP x TBV) - [(baseline COP x PPV) + (PV x COP)] / 20 (for FFP) or 80 (for albumin). PV x COP accounts for constituents already added to the prime

do not contribute to COP

PRBCs and clear prime