Quality Control; Interpretation Of Results; Performance Characteristics - Orion Diagnostica QuikRead CRP Manual De Instrucciones

Insert the cuvette
for measurement
Place the cuvette in the measurement well of the instrument. If the cuvette is inserted
back too early, the error message "Test cancelled" or "Cuvette inserted too early" will be
displayed. If the cuvette is reinserted too late, the error message "Cuvette inserted too late"
will be displayed. In both cases, a new test needs to be performed.
Measuring 120 s
The instrument measures the CRP concentration in 2 minutes. The display shows the time
left before completion. Do not remove the cuvette from the measurement well before the
result is given and recorded. Cuvette removal will terminate the measurement immediately.
Sample: <XXX> / date
Result: <XXX> CRP
The result is shown in the display as mg/l.
Performing self test
Wait....
When the cuvette is removed, the QuikRead 101 Instrument automatically performs a self-
check. If the self-check is not successful, discard the previous test result. After a successful
self-check the LCD will display:
Ready for use
CRP
To begin a new test, place a cuvette in the measurement well.
Brief instructions for use
1
Dispense 1 ml of buffer into the cuvette.
2
Add 20 µl of whole blood. Put the cap on and mix gently (not upside-down).
3
Blank measurement max. 40 seconds.
4
Add reagent by pressing down the inner part of the cap.
Take out the cuvette and mix thoroughly.
5
Put the cuvette back in the measurement well.
6
Instrument measures CRP concentration during 120 seconds.
7
Read the CRP result.
Sample dilution
QuikRead CRP gives a numerical value up to 160 mg/l. To obtain numerical values for higher
concentrations, the samples must be diluted and reanalysed. Take a new sample and analyse
it as follows:
1) Dispense 2 ml of buffer into the cuvette (two dispenser strokes).
2) Add 20 µl of whole blood. Mix.
3) Remove 1 ml of the mixture with a pipette and discard it.
4) Continue the test as above.
5) Multiply the result by 2.
8

Quality control

Regular use of QuikRead CRP Control (Cat. No. 68296) is recommended. The control value is
specified for a volume of 20 µl with the same instructions for use as for whole blood samples.
9

Interpretation of results

Increases in CRP are nonspecific and should not be interpreted without a complete clinical
history.
Elevated CRP range
Concentrations of < 10 mg/l exclude many acute inflammatory diseases but do not
specifically exclude inflammatory processes. Elevated concentrations of < 50 mg/l in
acute disease occur in the presence of slight to moderate inflammatory processes. Values
> 50 mg/l indicate high and extensive inflammatory activity
Effect of haematocrit for whole blood samples
The calibration of the reagents for whole blood has been made assuming that the value for
haematocrit is approximately 40 % and a plasma proportion is 60 %. If the actual haematocrit
value deviates from 40 %, the corrected CRP value can be calculated by multiplying the
whole blood result by the factor given below:
Haematocrit Factor
(%)
20–29 0.8
30–36 0.9
37–42 1.0
43–47 1.1
48–51 1.2
52–55 1.3
56–58 1.4
10 Limitations of the procedure
Assay procedures other than those specified in these instructions may yield questionable
results. Some substances may interfere with the test results; please see Section 12.
"Performance Characteristics". CRP results should never be used alone, without a complete
clinical evaluation. Intra- individual variations in CRP are significant and should be taken into
account – e.g., by means of serial measurements – in interpretation of the values.
11 Expected values
Measurement range:
Reference values:
It is recommended that each laboratory determine their own reference values according to
the health and age characteristics of their target populations.
12

Performance Characteristics

The following performance characteristics have been determined for the QuikRead 101
Instrument.
Precision and Reproducibility
An example of typical results:
Intra-assay precision (n=15)
CRP samples Mean (mg/l)
Sample 1 appr. 10
Sample 2 appr. 25
Sample 3
appr. 70
Sample 4 appr. 150
Detection limit:
Linearity:
Haematocrit
(%)
59–61
62–63
64–65
66–67
68–69
70
71–72
8–160 mg/l
< 10 mg/l
CV (%)
≤ 15
≤ 7
≤ 4
≤ 2
< 8.0 mg/l
99–115 % (at 143 mg/l)
.
8
Factor Haematocrit
(%)
1.5 73
1.6 74
1.7 75
1.8 76–77
1.9 78
2.0 79
2.1 80
Inter-assay precision (n=15)
CRP samples Mean (mg/l)
Sample 1 11
Sample 2 21
Sample 3 63
Sample 4 153
Factor
2.2
2.3
2.4
2.6
2.7
2.9
3.0
CV (%)
≤ 16
≤ 9
≤ 5
≤ 2