Roche cobas b 123 - Aado; Chco 3 - St; Pao

Roche Diagnostics
102 Instructions for Use · Version 13.0
4 Theoretical foundations cobas b 123 POC system
Parameters and calculations
Equation 4-18
cHCO
3
-
st
Standard bicarbonate of the blood, defined as the plasma bicarbonate concentration
in blood, which has been equilibrated at 37 °C with a gas mixture having a PCO
2
=
40 mmHg.
[3]
Unit: [mmol/L]
Equation 4-19
PAO
2
The alveolar oxygen partial pressure is used to calculate several parameters used for
oxidation and breathing.
[6]
Unit: [mmHg]
Equation 4-20
If the result of the calculation is PAO
2
< PO
2
, then PAO
2
is set to equal PO
2
.
Therefore, PACO
2
corresponds to the measured PCO
2
.
q
PAO
2
values are only provided for “arterial” or “capillary” blood types.
P
total
= Baro
R = RQ
u PAO
2
t
(p. 106) for patient temperatures other than 37 °C.
AaDO
2
The alveolar arterial oxygen partial pressure gradient (PAO
2
- PaO
2
) is the difference
between the alveolar oxygen partial pressure, as calculated above, and the measured
oxygen partial pressure of arterial blood.
[6]
Unit: [mmHg]
Equation 4-21
PaO
2
= PO
2
u AaDO
2
t
(p. 107) for patient temperatures other than 37 °C.
q
AaDO
2
values are only provided for “arterial” or “capillary” blood types.
pH)COlg(0.025BE)0.006942tHb0.01296(0.8262pH
2st
+⋅⋅⋅+⋅−= P
()
6.022 pH
st
3
st
10 HCO
−
−
=c
»
¼
º
«
¬
ª
−
+⋅−⋅−=
R
IO1
IOACOIO47)(O
2
222total2
A
F
FPFPP
AaDO
2
= PAO
2
- PaO
2