Roche cobas b 123 - Osm; Osm Opt; Osm Opt Gap

Roche Diagnostics
Instructions for Use · Version 13.0 109
cobas b 123 POC system 4 Theoretical foundations
Parameters and calculations
Equation 4-42
The calculation takes place with SO
2
or, if not available, with SO
2
(c).
Osm
Osmolality.
[10]
Unit: [mOsm/kg]
Equation for blood, plasma, serum:
Equation 4-43
Equation for aqueous solution, acetate, bicarbonate:
Equation 4-44
Default parameter values for calculating Osm:
Conditions for calculating Osm:
Osm
opt
Osmolatity (optimized).
[11]
Unit: [mOsm/kg]
Equation for blood, plasma, serum:
Osm
opt
= (Na
+
+ K
+
+ Cl
-
+ Lac + Glu + HCO
3-
+ Urea(e) + 6.5) * 0.985
Equation 4-45
q
Osm
opt
is only calculated if all measured, calculated and input values are available.
Osm
opt
Gap
Difference (gap) between measured and calculated osmolality.
[11]
Unit: [mOsm/kg]
o K
+
= 4.3 mmol/L
o Ca
2+
= 1.25 mmol/L
o Mg
2+
= 0.6 mmol/L
o Glu = 4.5 mmol/L
o Urea = 5 mmol/L
Na
+
:
If no measured value is available, osmolality is not calculated.
K
+
:
If no measured value is available, the default value is used.
Ca
2+
:
If no measured value is available, the default value is used.
Mg
2+
:
The default value is used.
Urea:
The default value is used.
Glu:
If no measured value is available, the default value is used.
9 UreaGlu Na1.86 Osm +++⋅=
+
UreaGlu )Mg (Ca 3 )K (Na 2 Osm
22
+++⋅++⋅=
++++