Portable lactate analyzer for measuring lactate in cerebrospinal fluid (CSF) and plasma - method-comparison evaluations.

ABSTRACT

UNLABELLED Increased plasma lactate levels can indicate the presence of metabolic disorders in HIV infected individuals. OBJECTIVE: To determine whether a portable analyzer is valid for measuring cerebrospinal fluid (CSF) and plasma lactate levels in HIV infected individuals. METHOD: CSF and plasma were collected from 178 subjects. Samples tested by the Accutrend portable analyzer were compared to those tested by a reference device (SYNCHRON LX 20). RESULTS: The portable analyzer had in plasma sensitivity of 0.95 and specificity 0.87. For CSF the specificity was 0.95; the sensitivity 0.33; the negative predictive value was 95% and the positive predictive value 33%. CONCLUSIONS: These findings support the validity of the portable analyzer in measuring lactate concentrations in CSF that fall within the normal range. The relatively poor positive predictive value indicates that a result above the reference range may represent a "false positive test", and should be confirmed by the reference device before concluding abnormality.