Evaluation of the Nova 2 Ionised Calcium Instrument
Author Information
Author(s): J.A. Fyffe, A.S. Jenkins, H.N. Cohen, F.J. Dryburgh, M.D. Gardner
Primary Institution: University Department of Medicine, Royal Infirmary, Glasgow
Hypothesis
Free or ionised calcium is the physiologically active fraction of plasma calcium.
Conclusion
The Nova 2 instrument provides a rapid and easy measurement of ionised calcium, but differences in results were observed between blood, plasma, and serum samples.
Supporting Evidence
- The calibration curve for the Nova 2 instrument was linear from 0.5 to 5.0 mM Ca, covering the expected physiological range.
- The practical response time for the instrument was approximately 33 seconds for aqueous solutions.
- Significant differences were found between the instruments when measuring blood, plasma, and serum.
- The precision of the instrument was less than the quoted 0.5% on blood and plasma samples.
Takeaway
The Nova 2 is a device that helps measure calcium in blood, and it works well, but sometimes gives different results depending on the type of blood sample.
Methodology
The study involved comparing the performance of the Nova 2 instrument with another device using blood, plasma, and serum samples from healthy laboratory staff.
Potential Biases
Differences in electrode performance may affect the results, necessitating a reference range for each electrode.
Limitations
The reference ranges are not well defined as they are derived from a narrow age range and a small number of subjects.
Participant Demographics
Healthy laboratory staff aged 20-50 years.
Statistical Information
P-Value
p < 0.001
Statistical Significance
p < 0.001
Want to read the original?
Access the complete publication on the publisher's website