Interference Testing Results For Thb, Fo; Fmethb, And Fhhb; Hb, Fcohb; Irenat (Sodium Perchlorate) Interference When Measuring Ionized Calcium - Siemens Rapidlab 1200 Operator's Manual

E-10

Interference Testing Results for tHb, FO

FMetHb, and FHHb

Potential Interferent
Lipid
Bilirubin
Fetal Hemoglobin
CyanMethemoglobin
Beta-carotene
Hemolysis
Evans Blue
Indocyanine Green
Methylene Blue
Methylene Blue
Sulfhemoglobin
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
• Do not measure Ca
• Ca
02087462 Rev.V
Level Tested
5% Intralipid in serum
40 mg/dL
20, 40, 85%
10%
40 mg/dL
10% volume
5 mg/L
5 mg/dL
25 mg/dL
40 mg/dL
10%
++
before administering Irenat.
++
while the patient is on Irenat.
++
may be measured 96 hours after the last dose of Irenat.
Rapidlab 1200 Operator's Guide: System Specifications

Hb, FCOHb,

2
Effect of Interference
No effect
No effect
No effect
No effect
No effect
No effect
No effect
No effect
FO Hb -1.2%
2
FCOHb +1.3%
FO Hb -2.0%
2
FCOHb +2.0%
tHb -0.8 g/dL
FO Hb -6.1%
2
FCOHb +3.6%
FMetHb +1.4%
FHHb +1.7%