Roche cobas b 123 - Reference and critical values

Roche Diagnostics
Instructions for Use · Version 13.0 115
cobas b 123 POC system 4 Theoretical foundations
Reference and critical values
Reference and critical values
The results of laboratory tests have little practical utility until clinical studies have
ascribed various states of health and disease to intervals of values
(1)
.
Reference intervals are useful because they attempt to describe the typical results
found in a defined population of apparently healthy people. Different methods may
yield different values, depending on calibration and other technical considerations.
Hence, different reference intervals and results may be obtained in different
laboratories. However, reference ranges may need to be adapted for specific patient
groups, whose physiological data are known to differ from the healthy population.
Reference intervals, although useful as a guideline for clinicians, should not be used
as absolute indicators of health and disease
(2)
.
WARNING
The reference intervals presented in this chapter are for general information
purposes only. Individual laboratories should generate their own set of reference
intervals.
Be sure to consider the QC and physiological ranges.
Reference/normal ranges
(1) Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 4th Edition 2006, p. 2252
(2) See Chapter 16 of “Tietz' Textbook of Clinical Chemistry and Molecular Diagnostics”. 4th Edition 2006
Parameter Normal range Sample matrix Unit Displayed/printed
default range
(1)
Source
pH 7.35–7.45 Whole blood arterial 7.350–7.450 Tietz Textbook of Clinical
Chemistry and Molecular
Diagnostics, 5th edition 2012, p.
2162
PO
2
83–108 Whole blood arterial mmHg 83.0–108.0 Tietz Textbook of Clinical
Chemistry and Molecular
Diagnostics, 5th edition 2012, p.
2162
PCO
2
32–45 (female adult)
35–48 (male adult)
Whole blood,
arterial heparin
mmHg
32–48 (all)
(2)
32–45 (female)
35–48 (male)
Tietz Textbook of Clinical
Chemistry and Molecular
Diagnostics, 5th edition 2012, p.
2137
Na
+
136–145 Serum, plasma mmol/L 136.0–145.0 Tietz Textbook of Clinical
Chemistry and Molecular
Diagnostics, 5th edition 2012, p.
2168
K
+
3.5–5.1 Serum mmol/L 3.50–5.10 Tietz Textbook of Clinical
Chemistry and Molecular
Diagnostics, 5th edition 2012, p.
2164
Cl 98–107 Serum, plasma mmol/L 98.0–107.0 Tietz Textbook of Clinical
Chemistry and Molecular
Diagnostics, 5th edition 2012, p.
2139
Table 4-3 Reference/normal ranges