Lactate measurement in whole blood using near infrared spectroscopy

The objective of the study was to evaluate the potential of Near Infrared S pectroscopy (NIRS) as a technique for rapid analysis of lactate in, whole b lood. In. order to test the NIRS technique, a comparison was made with enzy matic measurements using whole blood samples taken from exercising rats. Sp ectra were collected over the 2050-2400 nm spectral range with a 1 mm optic al path Length quartz cell. Reference Lactate concentrations in. the sample s were determined by enzymatic measurements. Estimates and calibration of t he lactate concentration with NIRS was made using Partial Least-Squares (PL S) regression analysis and leave-N-out cross validation on second derivativ e spectra. Regression analysis provided a correlation coefficient of 0.984 and a standard error of 0.29 mmol/l between, the enzymatic assay and the NI RS technique. The results suggest that NIRS may provide a valuable tool to assess physiological status for both research and clinical use.