Comparison of three different multi-analyte point-of-care devices during clinical routine on a medical ICU

Introduction

Multi-analyte point-of-care (POC) devices are important to guide clinical decisions in critical care. However, the use of different devices in one hospital might cause problems. We therefore evaluated three commonly used POC devices and analysed accuracy, reliability and bias.

Methods

Seventy-four arterial blood samples were analysed with three POC devices (Cobas, Roche (CO); ABL800 Flex, Radiometer (ABL); Gem Premiere, Instrumentation Laboratory (IL)). For selected parameters, samples were also analysed in the central laboratory. pCO₂, pO₂, SO₂, bicarbonate and standard bicarbonate (HCO₃ and HCO₃std), sodium, potassium, calcium, pH, lactate, base excess (BE(B) and BEecf), glucose, hemoglobin and hematocrit were compared.

Results

For most parameters only minor, although statistically significant, changes were observed between the POC devices. For pO₂, BE(B), hemoglobin and hematocrit, clinically significant differences were found. When for example looking at a pO₂ of 60 mmHg, in six out of 74 samples, IL and/or CO showed a pO₂ below 60 mmHg and ABL showed a pO₂ of above 60 mmHg. For hematocrit and hemoglobin, differences between the devices would result in different decisions regarding the use of packed red cells in 11 to 19% of the samples. For BE(B) in a total of 15% of measurements, the results obtained from the different devices would not agree whether a BE(B) is normal or not.

Conclusions

Although POC devices are of high standard and overall comparability between devices is high, there might be a clinically relevant bias between devices, as found in our study for pO₂, BE(B), hemoglobin and hematocrit. This can be of importance when interpreting results of the same patient obtained from different POC devices, as could happen when a patient is transferred within a hospital where different devices are used.