Oxygenation Indices Calculator

oxygenation indicies in ventilated patients

1)P/F= Pao2/fio2
- PaO2 (Partial Pressure Of Arterial O2,mmHg) from ABG
- FiO2 (Inspired Oxygen Concentration) from ventilator like 40%, 50%, up to 100%..enter it like 0.4(for 40% FiO2).
e.g. PaO2= 125 & FiO2 provided by ventilator is 70%
P/F= 125/0.70
= 178

2)a/A: PaO2/PAO2
-Pao2 (Partial Pressure Of Arterial O2, mmHg) from ABG report
-PAO2 = (760-PBO2)*FiO2-(PaCo2*1.25)
Where
760 - barometric pressure at sea level,
PBO2 - water vapour pressure=47,
FiO2 (Inspired Oxygen Concentration) from ventilator in decimal
PaCO2 (Partial Pressure Of Arterial CO2, mmHg) from ABG report
1.25 is constant & it is to be ignored when fio2 provided is more than 60%
e.g.. PaO2 =125, FiO2=40%(0.4), PaCO2= 35
PAO2=(760-47)*0.4-35*1.25
= 285.2-43.75
=241.45
a/A= 125/241.45
=0.517
3)oxygenation index(O.I.)= FiO2/PaO2*MAP
-Pao2 (Partial Pressure Of Arterial O2, mmHg) from ABG report
- FiO2 (Inspired Oxygen Concentration) from ventilator in decimal
-MAP (mean airway pressure, mmHg) from ventilator
e.g. FiO2=100%(1), PaO2 =225, MAP=14
O.I.= 100/225*14
= 6.2
4)Alveolar-arterial Gradient(A-a)=PAO2-PaO2
-Pao2 (Partial Pressure Of Arterial O2, mmHg) from ABG report
-PAO2 = (760-PBO2)*FiO2-(PaCo2*1.25)
Where
760 - barometric pressure at sea level,
PBO2 - water vapour pressure=47,
FiO2 (Inspired Oxygen Concentration) from ventilator in decimal
PaCO2 (Partial Pressure Of Arterial CO2, mmHg) from ABG report
1.25 is constant & it is to be ignored when fio2 provided is more than 60%
e.g.. PaO2 =125, FiO2=40%(0.4), PaCO2= 35
PAO2=(760-47)*0.4-35*1.25
= 285.2-43.75
=241.45
A-a=241.45-125
=116.45
5)Sodium Correction for Hyperglycemia(US Units,mg/dL)=
Serum Sodium+0.016(Serum Glucose-100)
-Serum Sodium(mEq/L)
-Serum Glucose(mg/dL)