Comparison of cord blood lactate measurement by gas analyzer and portable electrochemical devices

Objective: To compare the accuracy of cord blood lactate measurement using gas analyzer and portable devices in order to assess possibility of implementation of these devices in clinical practice. Methods: We performed a prospective observational study using 30 umbilical cord samples which were obtained immediately after birth. Portable electrochemical devices Lactate Scout (Sens Lab GmbH, Leipzig, Germany) and StatStrip Lactate (NOVA Biomedical, Waltham, MA, USA) were used to determine lactate level. A gas analyzer ABL800 FLEX (Radiometer Medical ApS, Bronshoj-Husum, Denmark) was used as a reference. Base excess (BE), pH, partial oxygen (pO(2)) and carbon dioxide (pCO(2)) pressure, hemoglobin (ctHb) and bilirubin (ctBl) levels were measured. Results: The mean umbilical cord blood lactate level determined by the gas analyzer was 5.85 +/- 2.66 mmol/L (ranging from 1.4 mmol/L to 13.4 mmol/L). Lactate level estimated by Lactate Scout was 5.66 +/- 2.65 mmol/L and did not significantly differ from the reference method level (P= 0.2547). The mean lactate level determined by StatStrip Lactate was significantly lower than by the gas analyzer - 4.81 +/- 2.38 mmol/L (P < 0.0001). Umbilical cord blood pH, BE, pO(2) and pCO(2), ctHb and ctBl levels did not affect the accuracy of the lactate measurement in absolute units (mmol/L). Conclusion: Umbilical cord blood lactate level measured by StatStrip Lactate was lower than estimated by the ABL800 FLEX gas analyzer. This shows the necessity to develop decision-making reference points separately for each device. Umbilical cord blood pH, BE, pO(2) and pCO(2), ctHb and ctBl levels did not affect the accuracy of measurements by electrochemical portable devices.