Extent of the bias differs between syringes
The study, published on Clinical Chemistry and Laboratory Medicine in December 2010, evaluated the effects of commercially available heparin-containing syringes for the bias on positively charged electrolytes in whole blood using an ABL735 blood gas analyzer.
The effects of heparin-containing syringes on ionized calcium, sodium, potassium and pH were determined in whole blood collected from 16 healthy donors in nonheparinized tubes and in electrolyte-balanced dry heparin containing syringes from three different manufactures:
- Becton Dickinson, Preset (heparin 80 IU)
- Sarstedt, Monovette (heparin 50 IU)
- Radiometer, PICO50 (heparin 80 IU)
According to authors, Dr. Miranda van Berkel and Dr. Volkher Scharnhorst from Clinical Laboratory, Catharina Hospital Eindhoven in the Netherlands, ionized calcium and sodium concentrations were significantly lower in blood collected in Becton Dickinson and Sarstedt syringes compared to nonheparinized blood. The mean bias exceeded biological variation-based total allowable error, which in most cases leads to clinically misleading individual results.
No bias on Radiometer PICO50 samplers
In contrast to Becton Dickinson and Sarstedt syringes, ionized calcium concentrations in blood collected in PICO50 samplers showed excellent agreement and were identical to values obtained from nonheparinized blood.
For the article “Electrolyte-balanced heparin in blood gas syringes can introduce a significant bias in the measurement of positively charged electrolytes”, go to:
Note: this as an abstract:
http://www.reference-global.com/doi/abs/10.1515/CCLM.2011.047