BeneVision N1 Patient Monitor Operator’s Manual
18 - 5
18.5.2
Input Parameters for Oxygenation Calculations
18.5.3
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
I
ml/min/m
2
DO2I (ml/min/m
2
) = CaO2 (ml/L) × (C.O. (L/
min)/BSA (m
2
))
oxygen consumption
VO
2
I
ml/min/m
2
VO2I (ml/min/m
2
) = C (a-v) O2 (ml/L) ×(C.O. (L/
min)/BSA (m
2
))