RADIOMETER FLEX ABL90, Reference Manual

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ABL90 FLEX reference manual 8. Parameters
8-25
Eq. 11 [5]:
 
Ery Ery
pH K
3
2 2
2
tCO (B) 9.286 10 CO tHb 1+10
tHb
tCO (P) 1
21.0
p
c p c
c
c


 
     

 
 
  
 
 
where
Eq. Description
11.1
   
Ery 2
pH 7.19 0.77 pH-7.40 0.035 1 O s      
11.2
 
Ery 2
pH 7.84 0.06 O
Ery
pK 6.095 log 1+10
s   
 
 
 
 
Eq. 12 [14]:
pH(st): see equations 5.3-5.5 below.
Eq. Description
5.3
2 2 2
5.33 pH(Hb) pH
pH(st) pH log
CO log CO (Hb) log(7.5006 CO ) p p p
   

  
   
   

   
5.4  
0.16169 tHb
2
pH(Hb) 4.06 10 tHb+5.98-1.92 10
c
c


  
5.5  
0.15158 tHb
2
2
log CO (Hb) 1.7674 10 tHb+3.4046+2.12 10
c
p c


   
Eq. 13 [15]:
Hct = 0.04939  ctHb
Hct cannot be calculated on the basis of a default ctHb value.
NOTICE: The formula is different from the formula used in previous Radiometer
analyzers. The previous formula Hct = 0.0485  ctHb+8.3  10
-3
was changed to
ensure that Hct=0 when ctHb=0. The slope was adjusted to make Hct identical
for the two formulas when ctHb=9.3087 mmol/L.
The change corresponds to 1% in the ctHb range 6.3-12.3.
Eq. 14 [16,17]:
The standard Oxygen Dissociation Curve (ODC) is used (i.e. p50(st) = 3.578
kPa) at actual values of pH, pCO
2
, FCOHb, FMetHb, FHbF (see equations 46-47
in the section Oxyhemoglobin dissociation curve (ODC) further in this chapter).
pO
2
(T) is calculated by a numerical method using:
 
i 2,i 2 2,i
t ( ) tHb 1- COHb - MetHb O ( ) O ( ) O ( ) c F F s T T p T

    
T
ctCO
2
(B)
pH(st)
Hct
pO
2
(T)