Bedside estimation of whole blood lactate.

A new instrument for the measurement of lactate in biological fluids, the Lactate Analyzer 640, has been evaluated. The method of use recommended by the manufacturer for blood samples was found to be inadequate. A new method of sample preparation for the instrument, based upon immediate haemolysis and fluoridation of blood, has been developed, allowing measurement of whole blood lactate concentration to be performed on samples as small as 150 microlitre within 5 min of withdrawal. The instrument is designed to be operated by a medical practitioner. Excellent correlation with a conventional enzymatic assay was found. These features make this new method particularly applicable to rapidly changing clinical situations such as shock in adult patients, asphyxia neonatorum and intrapartum foetal hypoxia.