Abbott i-STAT 1, System Manual

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Crea - 2
Art: 714183-00T Rev. Date: 03-Aug-12
plasma fraction of arterial, venous, or capillary whole blood (dimension μmol L -1 ) for
in vitro
diagnostic
use. Creatinine values assigned to i-STAT’s controls and calibration verification materials are traceable
to the U.S. National Institute of Standards and Technology (NIST) standard reference material SRM967.
i-STAT System controls and calibration verification materials are validated for use only with the i-STAT
System and assigned values may not be commutable with other methods. Further information regarding
metrological traceability is available from Abbott Point of Care Inc..
Expected Values
Reportable Reference
Test/Abbreviation Units* Range Range
Creatinine/Crea mg/dL 0.2 – 20.0 0.6 – 1.3
2
μmol/L 18 – 1768 53 – 115
To convert a creatinine result from mg/dL to μmol/L, multiply the mg/dL value by 88.4.
The i-STAT reference ranges for whole blood listed above are similar to reference ranges derived from
serum or plasma measurements with standard laboratory methods.
The reference range programmed into the analyzer and shown above is intended to be used as a guide
for the interpretation of results. Since reference ranges may vary with demographic factors such as age,
gender and heritage, it is recommended that reference ranges be determined for the population being
tested.
* The i-STAT System can be configured with the preferred units.
Clinical Significance
Elevated levels of creatinine are mainly associated with abnormal renal function and occur whenever
there is a significant reduction in glomerular filtration rate or when urine elimination is obstructed. The
concentration of creatinine is a better indicator of renal function than urea or uric acid because it is not
affected by diet, exercise, or hormones.
The creatinine level has been used in combination with BUN to differentiate between prerenal and renal
causes of an elevated urea/BUN.
Performance Characteristics
The typical performance data summarized below were collected in health care facilities by professionals
trained in the use of the i-STAT System and comparative methods. Clinical settings vary and some may
require different performance characteristics to assess renal function status than others (e.g., medication
dosing, intravenous contrast use, and outpatient clinic). If deemed necessary by a health care facility,
performance data should be obtained in specific clinical settings to assure patients’ needs are met.
Precision data were collected in multiple sites following the protocol recommended by Abbott Point of
Care. The means, SDs and CVs from 20 replicates at each site were averaged. The average statistics
are presented below.
Method comparison data were collected using CLSI guideline EP9-A
3
. Venous blood samples, collected
in lithium or sodium heparin Vacutainer
®
tubes, and arterial blood samples, collected in blood gas
syringes, were analyzed in duplicate on the i-STAT System. A portion of each specimen was centrifuged,
and the separated plasma was analyzed on the comparative method.
Deming regression analysis
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was performed on the first replicate of each sample. In the method
comparison table, n is the number of specimens in the data set, Sxx and Syy refer to the estimates of
imprecision based on the duplicates of the comparative and the i-STAT methods respectively, Sy.x is the
standard error of the estimate, and r is the correlation coefficient.*
Interference studies were based on CLSI guideline EP7.
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