Sign in →

Epic Test Code LAB91 Methemoglobin (NOVABIO)

Performing Location(s)

BMC,CRH,LFH,OCH,FTT,FOX

Available STAT

Yes

Specimen Type

Whole Blood

Preferred Container

Heparin coated syringe

Alternate Container

Lithium Heparin Green top tube

Specimen Tubes for Blood Gases

.

Blood Tube Draw Volume

Min 50% draw volume  

Minimum Volume to Submit for Testing

2 mL whole blood

Transportation Needs

Deliver ASAP within 15 minutes 
Do not send Green top tubes through pneumatic tube system.
Do not centrifuge.
Stable 24 hours at room temp.

Storage Requirements

Immediately after sampling using a syringe, the air must be evacuated and the syringe must be sealed. Deliver to lab immediately after sampling

Causes for Rejection

Mislabeled or unlabeled specimen
Specimen not received within 30 minutes of collection 
Contaminated with Room Air (bubbles in syringe or uncapped),
Clotted or Centrifuged
Pneumatic tube transport of Green top tubes
All other tubes or anticoagulant other than Lithium heparin whole blood

No Add-ons

Limitations

Errors can occur due to metabolic changes if there is a delay in the measurement of the sample

Severely abnormal plasma osmolarities or abnormal levels of proteins or lipids can potentially interfere w/ sample analysis.

As with all spectrophotometric methods, there are limitations regarding the optical determination of hemoglobin derivatives. In general, any substance which, in addition to the five hemoglobin derivatives to be determined, causes significant absorption or light scattering of the sample, may have a negative impact on the result

The following interfering substances have been shown to cause clinically significant effects.
Evans Blue  >0.125 mg/dL, Methylene Blue at any concentration, Patent Blue at >1.875 mg/dL and sulfgemoglobin at > 0.8%.

 

Reference Values

Population Units Reference Range
All Populations % ≤3.0
Cyanosis % 10-25
Headache % 35-40
Lethargy & Stupor % >60
Fatal % >70

 

Days of Analysis

All

Includes

Spectrophotometrically measured Methemoglobin (metHb) expressed as a fraction of the total hemoglobin.

Methodology

Multiple wavelength measurement of optical density to determine the concentration of [O2Hb] (oxyhemoglobin), [HHb] (deoxyhemoglobin), [MetHb] (methemoglobin) and [COHb] (carboxyhemoglobin).  The calculation then used to calculate the %MetHb  is: %MetHb= [MetHb]/([O2Hb] + [HHb] + [MetHb] + [COHb])

CPT Code

83050

Last Updated

8-JUN-23 MS