Mindray BeneVision N22 - Calculated Parameters and Formulas for Oxygenation Calculations

BeneVision N22/N19 Patient Monitor Operator’s Manual 33 - 7
33.5.3 Calculated Parameters and Formulas for Oxygenation Calculations
33.6 Ventilation Calculations
The monitor provides the ventilation calculation function. The monitor can save the results of up to 10
calculations, which are displayed in groups.
33.6.1 Performing Ventilation Calculations
To perform ventilation calculations, follow this procedure:
1. Access ventilation calculation by either of the following ways:
◆ Select the Calculations quick key → Ventilation tab.
◆ Select the Main Menu quick key → turn to the second page → from the Calculations column select
Ventilation.
2. Enter the known values. For a patient who is being monitored, the currently measured values are
automatically taken. If the anesthesia machine or ventilator is connected, measured values for ventilation
calculation are also automatically taken.
3. Select
Calculate.
The calculated value greater than the normal upper limit is indicated by an up arrow “
↑”. T h e c a l c u l a t e d
value lower than the normal lower limit is indicated by a down arrow “
↓”.
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
))