Near-patient blood gas and electrolyte analyses are accurate when performed by non-laboratory-trained individuals

Objective. The objective of this study was to determine the accuracy of a near-patient blood gas and electrolyte analyzer when used by non-laboratory-trained clinicians in the critical care setting. Methods. One hundred eighty-five blood samples (split samples) from 50 intensive care unit patients were analyzed by clinicians in the critical care environment using a near-patient blood gas and electrolyte analyzer (GEM Premier, Mallinckrodt Sensor Systems, Ann Arbor, MI). Near-patient measurements were compared with those obtained by laboratory technologists in an established intensive care unit laboratory. Results. There was good agreement between the near-patient analyzer and the laboratory for pH, {Mathematical expression}, sodium, potassium, ionized calcium, and hematocrit. Bias and precision were 0.006 and 0.03 for pH, 0.03 and 0.34 kPa for {Mathematical expression}, 0.78 and 2.61 mmol/L for sodium, -0.11 and 0.12 mmol/L for potassium, -0.007 and 0.05 mmol/L for ionized calcium, and -0.99 and 1.33% for hematocrit. Bias between the laboratory instrument and the bedside analyzer was small for PO₂ (-0.56 kPa). However, precision between instruments was significantly higher (2.39 kPa for all PO₂ values and 1.61 kPa for PO₂ ≤ 13 kPa). Conclusions. The test instrument is accurate and reproducible when used in the clinical setting by non-laboratory-trained individuals. Non-laboratory-trained individuals can obtain laboratory results in the near-patient setting comparable to those obtained by trained laboratory technologists.