Abbott i-STAT 1 System Manual page 538

E. Sample Volume Requirement
The i-STAT Total β-hCG cartridge requires a minimum sample volume of 17 µL to
fill. Excess amounts beyond this requirement will not impair the results. However,
excess blood or plasma will be present at the inlet of the cartridge and caution should
be observed in handling the cartridge to minimize biohazard exposure.
F. Specimen Collection and Preparation
i-STAT Total β-hCG cartridges require the use of either:
1. heparinized whole blood or plasma samples collected in plastic syringes or
evacuated tubes containing lithium or sodium heparin filled to capacity, or
2. non-heparinized whole blood samples tested within one minute of drawing
from a patient into a plastic syringe or plastic evacuated tube containing no
additives.
The use of whole blood or plasma samples containing other anticoagulants such
as EDTA, oxalate and citrate will cause deactivation of the alkaline phosphatase,
resulting in decreased β-hCG readings.
Performance characteristics have not been established for samples taken from
capillary tubes and direct skin punctures (e.g., fingersticks). These sample
types should not be used with the i-STAT Total β-hCG cartridge.
G. Test Limitations
• This assay is capable of detecting whole molecule (intact) hCG as well as free
β-hCG subunits.
• The i-STAT Total β-hCG assay is intended for use in the early detection of
pregnancy only and should not be performed for any other purpose.
• Elevated hCG levels have been associated with some abnormal physiological
states such as gestational trophoblastic disease and nontrophoblastic neoplasms,
including transitional cell carcinoma of the bladder and urinary tract, renal cancer,
prostate cancer, cancers of the gastrointestinal system, neuroendocrine tumors,
lung cancer, breast cancer, gynecological cancers, and hematological cancers.
Results of this test should not be used in the diagnosis of these abnormal states.
Persistent low levels of hCG (e.g., <50 IU/L) may be present one to five years
preceding malignant gestational trophoblastic disease.
reports of people receiving unnecessary medical treatment and surgery, including
chemotherapy and hysterectomy, when hCG results were used in the diagnosis
of abnormal states.
• For diagnostic purposes, hCG results should always be used in conjunction with
other data; e.g., patient's medical history, symptoms, results of other tests, clinical
impressions, etc. β-hCG cannot be used alone to establish the diagnosis of
ectopic pregnancy.
used and interpreted only in the context of the overall clinical picture.
2
The results from this or any other diagnostic test should be
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Art: 730475-01F
There have been
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Rev. Date: 14-Mar-16
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