B-276
Assessment of Harmonization among Siemens Point-of-care
and Central Laboratory Blood Gas Systems
Bethoney C, Fennell S, LaRock K, Poirier D.
Siemens Healthcare Diagnostics Inc., Norwood, MA, U.S.
pH
Objective
7.8
7.6
Identity
vs. RAPIDLab 1265
7.4
vs. RAPIDLab 348EX*
vs. RAPIDPoint 405
7.2
• RAPIDPoint 405 Blood Gas System vs. RAPIDPoint 500 Blood Gas System
Validation
Deming regression statistics for each comparison across intervals for
each measurand are shown in Tables 1 through 3. The mean of the
replicates for each measurand and the identity line are depicted in
Figures 1 through 11. The arrows on each figure indicate clinically
relevant medical decision levels (MDLs) for the following measurands
that are available on Siemens blood gas systems:
vs. RAPIDLab 1265
vs. RAPIDLab 348EX*
80
vs. RAPIDPoint 405
Identity
vs. RAPIDLab 1265
400
vs. RAPIDLab 348EX*
vs. RAPIDPoint 405
300
200
100
0
0
6.8
6.8
7.0
7.2
7.4
7.6
7.8
0
8.0
40
80
120
160
0
180
Figure 1. pH method comparison of comparative systems vs.
the RAPIDPoint 500 system.
Potassium (K+)
Identity
160
vs. RAPIDLab 1265
vs. RAPIDLab 348EX*
vs. RAPIDPoint 405
140
120
10
Identity
8
vs. RAPIDLab 1265
vs. RAPIDLab 348EX*
6
vs. RAPIDPoint 405
4
0
• pH, pCO2, pO2
140
160
180
0
200
2
• Total hemoglobin, neonatal bilirubin
Table 1. Method comparison statistics for RAPIDLab 1265 vs.
RAPIDPoint 500 systems.
4
6
8
10
3
vs. RAPIDLab 1265
vs. RAPIDLab 348EX*
vs. RAPIDPoint 405
2
1
0
12
0
1
Intercept
r
2
Interval
1.01
-0.034
0.9988
6.820 to 7.781
pCO2 (mmHg)
103
0.8
3.1
1.12
-2.7
0.9887
6.9 to 190.4
pO2 (mmHg)
114
4.1
9.2
1.04
2.2
0.9965
27.6 to 653.3
Na+ (mmol/L)
124
0.1
0.7
1.03
-3.9
0.9976
100.4 to 198.3
K+ (mmol/L)
105
-0.07
0.22
1.10
-0.35
0.9982
0.62 to 10.00
Ca2+ (mmol/L)
133
-0.01
0.00
1.06
-0.07
0.9977
0.31 to 4.86
Cl- (mmol/L)
124
2
3
1.08
-5
0.9944
66 to 140
Glucose (mg/dL)
100
5
4
0.99
6
0.9981
26 to 683
Lactate (mmol/L)
100
0.17
0.13
0.98
0.20
0.9870
0.31 to 27.13
tHb (g/dL)
112
-0.1
0.0
1.01
-0.1
0.9997
2.5 to 23.8
nBili (mg/dL)
110
0.9
1.1
1.03
0.7
0.9732
2.3 to 27.4
Table 2. Method comparison statistics for RAPIDLab 348EX* vs.
RAPIDPoint 500 systems.
Bias at
MDL 1
Bias at
MDL 2
pH (units)
113
0.009
0.007
Deming
Intercept
Slope
0.99
0.103
r2
Interval
0.9981
6.820 to 7.781
pCO2 (mmHg)
109
2.1
2.3
1.01
1.8
0.9833
6.6 to 198.6
pO2 (mmHg)
113
2.5
10.2
1.05
-0.5
0.9950
27.6 to 653.3
Na+ (mmol/L)
124
3.1
2.3
0.96
8.3
0.9959
100.4 to 198.3
K+ (mmol/L)
101
0.06
0.22
1.05
-0.09
0.9973
0.62 to 9.06
Ca2+ (mmol/L)
121
0.06
0.11
1.25
-0.21
0.9974
0.31 to 4.18
Cl- (mmol/L)
124
0
1
1.06
-6
0.9942
66 to 140
Table 3. Method comparison statistics for RAPIDPoint 405 vs.
RAPIDPoint 500 systems.
130
Identity
120
vs. RAPIDLab 1265
110
vs. RAPIDLab 348EX*
100
vs. RAPIDPoint 405
90
80
n
Bias at
MDL 1
Bias at
MDL 2
Deming
Intercept
Slope
r2
Interval
pH (units)
116
-0.003
-0.002
1.00
-0.038
pCO2 (mmHg)
110
0.4
1.8
1.07
-1.6
0.9785
6.6 to 190.4
pO2 (mmHg)
116
0.8
5.4
1.03
-0.9
0.9970
27.6 to 653.3
Na+ (mmol/L)
124
0.6
0.8
1.01
-0.2
0.9979 100.4 to 198.3
K+ (mmol/L)
104
0.00
0.02
1.01
-0.03
0.9992
1.31 to 10.00
Ca2+ (mmol/L)
133
0.00
-0.01
0.96
0.04
0.9973
0.31 to 4.86
Cl- (mmol/L)
119
0
2
1.09
-8
0.9974
66 to 137
Glucose (mg/dL)
100
3
0
0.98
4
0.9972
26 to 683
tHb (g/dL)
112
-0.1
0.0
1.01
-0.2
0.9996
2.5 to 23.8
nBili (mg/dL)
110
0.1
0.1
1.01
0.0
0.9944
2.3 to 27.4
0.9987 6.820 to 7.781
580
500
Identity
420
vs. RAPIDLab 1265
vs. RAPIDPoint 405
340
260
180
25
20
Identity
15
vs. RAPIDLab 1265
10
5
70
100
60
20
60
70
80
90
100
110
120
130
140
150
0
20
100
RAPIDPoint 500 System Mean Results (mmol/L)
180
260
340
420
500
580
0
660
Figure 7. Cl- method comparison of comparative systems vs.
the RAPIDPoint 500 system.
Figure 8. Glucose method comparison of comparative systems vs.
the RAPIDPoint 500 system.
Total Hemoglobin (tHb)
30
20
Identity
vs. RAPIDLab 1265
15
vs. RAPIDPoint 405
10
5
10
15
20
25
30
Figure 9. Lactate method comparison of comparative systems vs.
the RAPIDPoint 500 system.
Conclusion
Neonatal Bilirubin (nBili)
25
5
RAPIDPoint 500 System Mean Results (mmol/L)
RAPIDPoint 500 System Mean Results (mg/dL)
25
Identity
Harmonization at clinically relevant medical decision levels was
demonstrated among Siemens POC and central lab blood gas systems
for the measurands evaluated. The slopes for each measurand were
between 0.96 and 1.25, with r2 ≥ 0.9785.
20
vs. RAPIDLab 1265
vs. RAPIDPoint 405
15
References
1. Malone B. AACC’s Thought Leadership Series:
Why Harmonization Matters.
10
5
0
0
Measurand
30
Comparative Systems (mmol/L)
0.018
Comparative Systems (mg/dL)
0.017
Comparative Systems (mg/dL)
114
n
5
140
pH (units)
Measurand
4
Lactate
660
Comparative Systems (g/dL)
n
Deming
Slope
3
Figure 6. Ca2+ method comparison of comparative systems vs.
the RAPIDPoint 500 system.
Glucose
Chloride (Cl-)
Comparative Systems (mmol/L)
Measurand
Bias at
MDL 2
2
RAPIDPoint 500 System Mean Results (mmol/L)
Figure 5. K+ method comparison of comparative systems vs.
the RAPIDPoint 500 system.
150
Bias at
MDL 1
700
Identity
• Sodium, potassium, ionized calcium, chloride
Figure 4. Na+ method comparison of comparative systems vs.
the RAPIDPoint 500 system.
600
4
RAPIDPoint 500 System Mean Results (mmol/L)
RAPIDPoint 500 System Mean Results (mmol/L)
• Glucose, lactate
500
5
2
100
400
Calcium (Ca2+)
12
180
300
Figure 3. pO2 method comparison of comparative systems vs.
the RAPIDPoint 500 system.
200
120
200
RAPIDPoint 500 System Mean Results (mmHg)
Figure 2. pCO2 method comparison of comparative systems vs.
the RAPIDPoint 500 system.
Sodium (Na+)
100
100
RAPIDPoint 500 System Mean Results (mmHg)
RAPIDPoint 500 System Mean Results (Units)
Comparative Systems (mmol/L)
• RAPIDLab 348EX* Blood Gas System vs. RAPIDPoint 500 Blood Gas System
120
500
7.0
Comparative Systems (mmol/L)
• RAPIDLab 1265 Blood Gas System vs. RAPIDPoint 500 Blood Gas System
Identity
600
40
Methodology
Method comparison studies were performed with whole blood
among POC (RAPIDPoint®) and central lab (RAPIDLab®) blood gas
systems in accordance with the CLSI EP-09 guideline. A minimum of
100 whole blood replicates were assayed on all systems listed below.
Samples were altered as needed to span the reportable ranges for
each measurand. Correlation statistics including Deming slopes,
intercepts, and coefficients of determination (r2) were generated for
the following comparisons:
160
Comparative Systems (mmHg)
700
Comparative Systems (mmHg)
AACC’s International Consortium for Harmonization of Clinical Laboratory
Results has been working with a variety of stakeholders regarding
harmonization among results from different methods and labs for
the same measurand.1 Malone states, “Harmonization means achieving
comparable results among different measurement procedures.” Further,
“When lab measurement procedures give different results for the same
specimen, patients may get the wrong treatment, because decision
criteria are not appropriate for the procedure in use. In order to do this
effectively, results need to be harmonized.”
Partial Pressure Oxygen (pO2)
200
Comparative Systems (mmol/L)
Relevance
8.0
Comparative Systems (Units)
Determine correlations between Siemens point-of-care (POC) and
central lab blood gas systems in order to demonstrate harmonization
across the product portfolio.
Partial Pressure Carbon Dioxide (pCO2)
0
5
10
15
20
25
RAPIDPoint 500 System Mean Results (g/dL)
Figure 10. tHb method comparison of comparative systems vs.
the RAPIDPoint 500 system.
0
5
10
15
20
25
30
RAPIDPoint 500 System Mean Results (mg/dL)
Figure 11. Neonatal bilirubin method comparison of comparative
systems vs. the RAPIDPoint 500 system.
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RAPIDPoint, RAPIDLab, and all associated products are trademarks
of Siemens Healthcare Diagnostics Inc. All other trademarks
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07-2014 | All rights reserved | ©2014 Siemens Healthcare Diagnostics Inc.
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