Abbott i-STAT 1 System Manual page 436

Interference studies were based on CLSI guideline EP7-A2.
CLSI guideline unless otherwise indicated.
When added to a plasma pool, the following substances (at the concentration indicated) were
found to interfere with the i-STAT Ionized Calcium assay:
Substance
Acetaminophen
Acetylcysteine
Bromide
Magnesium
Lactate
Nithiodote (sodium thiosulfate)
Salicylate
Salicylate (therapeutic)
Thiocyanate
The following substances are known not to significantly interfere with the i-STAT Ionized Calcium
assay at the stated test concentrations:
Substance
Acetaminophen (therapeutic)
Acetylcysteine (therapeutic)
Ascorbate
Bromide (therapeutic)
β-Hydroxybutyrate
Notes:
1) Acetaminophen has been shown to interfere at a concentration proscribed by the CLSI guideline,
1.32 mmol/L, which represents a toxic concentration. Acetaminophen at 0.132 mmol/L, which represents
the upper end of the therapeutic concentration, has been shown not to significantly interfere with i-STAT
ionized calcium results.
2) Acetylcysteine has been tested at two levels; the CLSI recommended level and a concentration of
0.30 mmol/L. The latter is 3 times the peak plasma therapeutic concentration associated with treatment
to reverse acetaminophen poisoning. APOC has not identified a therapeutic condition that would lead
to levels consistent with the CLSI recommended level. Acetylcysteine at a concentration of 10.2 mmol/L
decreased i-STAT ionized calcium results, while acetylcysteine at a concentration of 0.3 mmol/L did not
significantly interfere with ionized calcium results.
3) Bromide has been tested at two levels; the CLSI recommended level and a therapeutic plasma
concentration level of 2.5 mmol/L. The latter is the peak plasma concentration associated with halothane
anesthesia, in which bromide is released. APOC has not identified a therapeutic condition that would
lead to levels consistent with the CLSI recommended level. Bromide at a concentration of 37.5 mmol/L
increased i-STAT ionized calcium results, while bromide at a concentration of 2.5 mmol/L did not
significantly interfere with i-STAT ionized calcium results.
4) Salicylate has been shown to significantly decrease ionized calcium results at a concentration
proscribed by the CLSI guideline, 4.34 mmol/L, which represents a toxic concentration.Salicylate at
0.5 mmol/L, which represents the upper end of the therapeutic concentration, has been shown to
iCa - 4
Test Concentration
(mmol/L)
1.32
10.2
37.5
Increased i-STAT Ionized Calcium results by
1.0
Decreased i-STAT Ionized Calcium results by
6.6
16.7
14
4.34
Decreased i-STAT Ionized Calcium results by
0.5
9
6.9
Art: 714179-01P
Test concentrations used were as per the
6
Interference
Decreased i-STAT Ionized Calcium results.
See Note below.
Decreased i-STAT Ionized Calcium results.
See Note below.
Use another method.
See Note below.
up to 0.04 mmol/L.
up to 0.07 mmol/L.
Decreased i-STAT Ionized Calcium results.
See Note below.
Decreased i-STAT Ionized Calcium results.
See Note below.
up to 0.03 mmol/L. See Note below.
Decreased i-STAT Ionized Calcium results.
Use another method.
Test Concentration
(mmol/L)
0.132
0.30
7,8
0.34
2.5
10,11,12
6.0
13
Rev. Date: 15-Jul-16