Mindray ePM 12MC - Page 215

23 - 5
23.5.2 Input Parameters for Oxygenation Calculations
23.5.3 Calculated Parameters and Formulas for Oxygenation Calculations
Input Parameter Label Unit
cardiac output C.O. L/min
percentage fraction of inspired oxygen FiO
2
%
partial pressure of oxygen in the arteries PaO
2
mmHg, kPa
partial pressure of carbon dioxide in the arteries PaCO
2
mmHg, kPa
arterial oxygen saturation SaO
2
%
partial pressure of oxygen in venous blood PvO
2
mmHg, kPa
venous oxygen saturation SvO
2
%
hemoglobin Hb g/L, g/dl, mmol/L
respiratory quotient RQ None
atmospheric pressure ATMP mmHg, kPa
height Height cm, inch
weight Weight kg, lb
Calculated Parameters Label Unit Formula
body surface area BSA m
2
BSA (m
2
) = Wt
0.425
(kg) × Ht
0.725
(cm) × 0.007184
oxygen consumption VO
2
ml/min VO
2
(ml/min) = C(a-v)O
2
(ml/L)× C.O. (L/min))
arterial oxygen content CaO
2
ml/L, ml/dL CaO
2
(ml/L) = 10× (0.0134 × Hb (g/dl) × SaO
2
(%))
+0.031× PaO
2
(mmHg)
venous oxygen content CvO
2
ml/L, ml/dL CvO
2
(ml/L) = 10× (0.0134 × Hb (g/dl) × SvO
2
(%))
+0.031 × PvO
2
(mmHg)
arteriovenous oxygen
content difference
C(a-v)O
2
ml/L, ml/dl C(a-v)O
2
(ml/L) = CaO
2
(ml/L) - CvO
2
(ml/L)
oxygen extraction ratio O
2
ER % O
2
ER (%) = 100×C(a-v)O
2
(ml/L)/CaO
2
(ml/L)
oxygen transport DO
2
ml/min DO
2
(ml/min) = C.O. (L/min) × CaO
2
(ml/L)
partial pressure of oxygen
in the alveoli
PAO
2
mmHg, kPa PAO
2
(mmHg) = [ATMP (mmHg) - 47 mmHg] ×
FiO
2
(%)/100 - PaCO
2
(mmHg) × [FiO
2
(%)/100 +
(1 - FiO
2
(%)/100)/RQ]
alveolar-arterial oxygen
difference
AaDO
2
mmHg, kPa AaDO
2
(mmHg) = PAO
2
(mmHg) - PaO
2
(mmHg)
capillary oxygen content CcO
2
ml/L, ml/dl CcO
2
(ml/L) = Hb (g/L) × 1.34 + 0.031 × PAO
2
(mmHg)
venous admixture QS/QT
% QS/QT (%) = 100× [1.34 × Hb (g/L) × (1 - SaO2 (%)/100) +
0.031 × (PAO2 (mmHg) - PaO2 (mmHg))]/[1.34 × Hb (g/L) × (1
- SvO2 (%)/100) + 0.031× (PAO2 (mmHg) - PvO2 (mmHg))]
oxygen transport index DO
2
Iml/min/m
2
DO2I (ml/min/m
2
) = CaO2 (ml/L) × (C.O. (L/min)/
BSA (m
2
))
oxygen consumption VO
2
Iml/min/m
2
VO2I (ml/min/m
2
) = C (a-v) O2 (ml/L) ×(C.O. (L/
min)/BSA (m
2
))