Abbott i-STAT 1 System Manual page 430

Sodium
Bromide
*It is possible that other interfering substances may be encountered. These results are representative and your results may differ somewhat due to
test-to-test variation. The degree of interference at concentrations other than those listed might not be predictable.
Sample Collection and Handling
Erroneous hematocrit results can be obtained by improper sample handling.
n Hematocrit results can be affected by the settling of red blood cells in the collection device. The
best way to avoid the affect of settling is to test the sample immediately. If there is a delay in
testing of a minute or more, the sample must be remixed thoroughly:
o If the sample is in a collection tube, invert the tube gently 10 times.
o If the sample is in a syringe, roll the syringe between the palms for five seconds in one
direction, then roll in a second direction for five seconds, then gently invert repeatedly for five
seconds. Note that it may not be possible to adequately mix a blood sample in a 1 mL syringe.
Samples from 1 mL syringes should not be used to determine hematocrit if testing is delayed.
Discard one or two drops of blood from a syringe before filling a cartridge.
n Low hematocrit results can be caused by contamination of flush solutions in an arterial or
venous line.
o Back flush a line with a sufficient amount of blood to remove intravenous solutions, heparin or
medications that may contaminate the sample. Five to six times the volume of the catheter,
connectors and needle is recommended.
Cartridge Comparison
The performance characteristics of the sensors are equivalent in all cartridge configurations. System
difference analysis was performed on 40 patient samples using the i-STAT 6+ and i-STAT E3+ cartridges.
In the 15–30 %PCV range the average difference was 0.462. In the 30–50 %PCV range the average
difference was 0.097.
Calculated Result for Hemoglobin
The i-STAT System provides a calculated hemoglobin result which is determined as follows
hemoglobin (g/dL) = hematocrit (% PCV) x 0.34
hemoglobin (g/dL) = hematocrit (decimal fraction) x 34
To convert a hemoglobin result from g/dL to mmol/L, multiply the displayed result by 0.621. The calculation
of hemoglobin from hematocrit assumes a normal MCHC.
Hct - 4
The sample electrolyte concentration is used to correct the measured conductivity
prior to reporting hematocrit results. Factors that affect sodium will therefore also
affect hematocrit.
Bromide (37.5 mmol/L) is known to result in an increased rate of star (***) outs.
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 the rate of HCT star (***) outs, while a therapeutic range of
bromide (2.5 mmol/L) did not significantly interfere with i-STAT HCT results.
Art: 714178-01O
:
7
Rev. Date: 15-Aug-16