Siemens Rapidlab 1200, Operator'S Manual, Page: 370 / 448

E-10 Rapidlab 1200 Operator’s Guide: System Specifications
02087462 Rev.V
Interference Testing Results for tHb, FO
2
Hb, FCOHb,
FMetHb, and FHHb
Irenat (Sodium Perchlorate) Interference when Measuring
Ionized Calcium
Samples containing Irenat (sodium perchlorate) can cause interference when measuring
ionized calcium because Irenat can falsely lower ionized calcium results. The results for
patients treated with Irenat to prevent Hyperthyroidism when using X-ray contrast
medications show discrepancies when compared with typical ionized calcium results.
Irenat blocks the anionic iodide transporter in the thyroid.
Low PTH and hypocalcemia are possible outcomes after thyroid surgery. Therefore
ionized calcium can not be tested to detect hypocalcemia while Irenat is still in the system.
The following guidelines should be followed if a patient is on Irenat when ionized calcium
is measured:
• Measure Ca
++
before administering Irenat.
• Do not measure Ca
++
while the patient is on Irenat.
• Ca
++
may be measured 96 hours after the last dose of Irenat.
Potential Interferent Level Tested Effect of Interference
Lipid 5% Intralipid in serum No effect
Bilirubin 40 mg/dL No effect
Fetal Hemoglobin 20, 40, 85% No effect
CyanMethemoglobin 10% No effect
Beta-carotene 40 mg/dL No effect
Hemolysis 10% volume No effect
Evans Blue 5 mg/L No effect
Indocyanine Green 5 mg/dL No effect
Methylene Blue 25 mg/dL F O
2
Hb -1.2%
F COHb +1.3%
Methylene Blue 40 mg/dL F O
2
Hb -2.0%
F COHb +2.0%
Sulfhemoglobin 10% tHb -0.8 g/dL
F O
2
Hb -6.1%
F COHb +3.6%
F MetHb +1.4%
F HHb +1.7%