C. Hamilton1, B. Engelhardt2, F. Weinbrenner2, D. Marin2
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 2017 Association for the Advancement of Medical Instrumentation: ANSI/AAMI/ISO 7199:2016.
Body Mass Index formula:
BMI (kg/m2) = weight (kg) / Height (m*m)
Where kg is kilograms and m is meters.
CaO2: CaO2 mlO2/L = Hgb*1.36*SaO2
Delivery of Oxygen Index formula:
DaO2i = Hgb(gms/l) * 1.36(mlO2/gmHgb) * CI (l/min/m2) * SaO2 + paO2 * 0.03(mlO₂/mmHg/l) * CI
Where DaO2i is the delivery of oxygen index in mlO2/min/m2, Hgb is the hemoglobin in gms/l, the Hüfner factor is 1.36 mlO2/gmHgb, CI is the cardiac index in l/min/m2, the SaO2 is the arterial saturation as a fraction, and paO2 is the pressure of oxygen in mmHg.
For ease of calculation, the modified short form may be used during CPB: DaO2i = (Hgb*1.36* CI).
*Since this short form does not include the pO2s, the SaO2 is considered to be 1.
Dilutional hematocrit formula
TBV = dilutional HCT*(Volume preCPB+ Prime volume)/(drop in HCT)
TBV is Total Blood Volume in ml, dilutional HCT is the first hematocrit taken on CPB, volume pre-CPB is the volume given and volume lost pre-CPB, plus the prime volume in ml, and the drop in hematocrit is the difference between the HCT pre-CPB and the HCT on CPB.
Calculating cFiO2:150 mmHg:
Step 1) Convert PaO2 into a fraction (FaO2) by taking the PaO2 and dividing this by the barometric pressure (Pb) minus the water vapor pressure of 47 mmHg (713).
*Pb = Barometric pressure (taken as 760 mmHg).
Step 2) The FiO2 minus the FaO2 gives the anoxic fractional difference (AFD). The AFD is the FiO2 at which the PaO2 is zero.
Step 3) Add 0.21 to the AFD to obtain the cFiO2
Final formula: cFiO2:150 mmHg = FiO₂-(PaO2 /(713)+0.21
*The cFiO2 is referred to as the “cFiO2:150mmHg” so the standard of using a specific PaO2 is clearly stated.