A study conducted by British researchers and published in the Emergency Medicine Journal gives new credence to point-of-care (POCT) blood gas analyzer tests for measuring calcium and electrolytes. Authors of the study say that doctors could rely on these POCT results as opposed to waiting for laboratory-based results.

Electrolyte disturbances are easily treated in the medical setting, yet patients can become seriously ill if the condition isn’t diagnosed and treated quickly enough. “This is one of the reasons that the repertoire of modern ward-based blood gas analysers includes sodium, potassium and ionised calcium,” the researchers explained. “In the presence of abnormal results, clinicians need to know whether the results obtained by such [POCT] devices are reliable and how they compare with those generated in the laboratory.”

Rather than relying solely on POCT blood gas analyzer tests, it is common practice for doctors to confirm POCT results with laboratory tests. The drawback is that waiting for lab results can delay treatment for patients who need urgent care.

To determine if POCT tests could measure up to those in the lab, researchers over a 5-year time period analyzed sodium, potassium, and ionized calcium on blood gas analyzer tests, comparing them with corresponding tests the same patients received in a laboratory within an hour’s time. More than 11,000 paired samples from labs at three hospital locations, and a laboratory information management system database were used to help compile the results.

Overall, the researchers found “sufficient agreement” among the laboratory and blood gas results for sodium, potassium and calcium.

Intense treatment unit (ITU) settings yielded stronger correlations among the POCT and lab tests than in the emergency department, possibly because of a more controlled clinical environment in the ITU. “When analysed according to requesting locations, the correlation between laboratory and POC results for sodium, potassium (n=2088) and calcium (n=363), were 0.87, 0.83 and 0.62, respectively, for emergency medicine and 0.94, 0.88 (n=10 087) and 0.74, respectively, for intensive treatment unit (ITU) (n=9068).”

Based on these results, the study’s authors suggest that their fellow clinicians increase their reliance on blood gas analyzer results as a means of responding to patients experiencing electrolyte disturbances.

“This will enable them to act more quickly and reduce any adverse consequence of delays for the patient,” they concluded