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Meningitis: The utility of lactic acid determination
The Journal of Emergency Medione. Vol. 1,
MENINGITIS:
pp.553-554,
THE UTILITY
1984
Printed I” the USA
Copyright % 1984 Pergamon Press Ltd
??
OF LACTIC ACID DETERMINATION
The rapid evolution of technology and its application to diagnostic and therapeutic aspects of medicine have placed enormous stress upon the clinician, who must constantly evaluate the benefit of a procedure or test against the costs, both financial and human. Nanji and Whitlow’ review the usefulness of lactic acid measurements in a variety of clinical settings, focusing initially on its value in the early diagnosis of bacterial meningitis. Before we embrace this determination, it is important to place the observations made by several authors into perspective. Lactic acid is increased in many cases of bacterial meningitis, but the most important observation has been the overlap between levels in patients with meningitis and those without demonstrable CNS disease. Furthermore, lactic acid is increased in many conditions with reduced cerebral blood flow and subsequent hypoxia, such as head trauma and subarachnoid hemorrhage as well as neonatal asphyxia.2,3 Analysis of our own data* concerning the utility of lactic acid reveals that the average lactic acid level in patients with bacterial meningitis was 6.28 mmol/L, whereas those without demonstrable viral or bacterial disease had a CSF level of 2.04 mmol/L. However, the range of levels in
bacterial meningitis was 1.82 to 8.85 mmol/ L contrasted with the range in the normal population of 0.46 to 8.0 mmol/L. This overlap creates immense problems in relying upon lactic acid determinations in the early diagnosis of bacterial meningitis. From the available data, there is little to substantiate that lactic acid determinations add to the specificity or sensitivity of the present analysis, which routinely includes cell count with differential, glucose, protein, and Gram’s stain (with culture). Until such documentation is available, lactic acid levels must have a very restricted role in the analysis of cerebrospinal fluid to exclude infection. The addition of a laboratory test without proven value in improving the specificity or sensitivity of the analysis only adds to the cost of health care without demonstrable return to the clinician. Furthermore, should we wish to focus on parameters that may increase the reliability of our diagnosis of bacterial meningitis beyond those readily available, other determinations should be considered in a large prospective study including lactic acid dehydrogenase, creatinine phosphokinase BB, phosphohexose isomerase, etc.4 Only after such studies can we address the true value of lactic acid in assisting in the differential diagnosis of meningitis.
*Supported in part by Grant #RR-69, Division of Research Resources, National Institutes of Health.
Roger Barkin, MD JEM Section Editor, Clinical Pediatrics
REFERENCES 1. Nanji AA, Whitlow KJ: Clinical utility of lactic acid measurement in body fluids other than plasma. J Emerg Med 1984; 1521-526.
2. Gastrin B, Briem H, Rombo L: Rapid diagnosis of meningitis with use of selected clinical data and gas liquid chromatographic determination of lactate
553
554
concentration in cerebrospinal fluid. J Infect Dis 1979; 139529. 3. Controni G, Rodriquex WJ, Hicks JM, et al: Cerebrospinal fluid lactic acid levels in meningitis. J Pediatr 1971; 91~379.
The Journal of Emergency Medicine
4. Jakoby RK, Jakoby WB: Lactic dehydrogenase of
cerebrospinal fluid in the differential diagnosis of cerebrovascular disease and brain tumor. J Neurosurg 1958; 15:45.
MENINGITIS:
pp.553-554,
THE UTILITY
1984
Printed I” the USA
Copyright % 1984 Pergamon Press Ltd
??
OF LACTIC ACID DETERMINATION
The rapid evolution of technology and its application to diagnostic and therapeutic aspects of medicine have placed enormous stress upon the clinician, who must constantly evaluate the benefit of a procedure or test against the costs, both financial and human. Nanji and Whitlow’ review the usefulness of lactic acid measurements in a variety of clinical settings, focusing initially on its value in the early diagnosis of bacterial meningitis. Before we embrace this determination, it is important to place the observations made by several authors into perspective. Lactic acid is increased in many cases of bacterial meningitis, but the most important observation has been the overlap between levels in patients with meningitis and those without demonstrable CNS disease. Furthermore, lactic acid is increased in many conditions with reduced cerebral blood flow and subsequent hypoxia, such as head trauma and subarachnoid hemorrhage as well as neonatal asphyxia.2,3 Analysis of our own data* concerning the utility of lactic acid reveals that the average lactic acid level in patients with bacterial meningitis was 6.28 mmol/L, whereas those without demonstrable viral or bacterial disease had a CSF level of 2.04 mmol/L. However, the range of levels in
bacterial meningitis was 1.82 to 8.85 mmol/ L contrasted with the range in the normal population of 0.46 to 8.0 mmol/L. This overlap creates immense problems in relying upon lactic acid determinations in the early diagnosis of bacterial meningitis. From the available data, there is little to substantiate that lactic acid determinations add to the specificity or sensitivity of the present analysis, which routinely includes cell count with differential, glucose, protein, and Gram’s stain (with culture). Until such documentation is available, lactic acid levels must have a very restricted role in the analysis of cerebrospinal fluid to exclude infection. The addition of a laboratory test without proven value in improving the specificity or sensitivity of the analysis only adds to the cost of health care without demonstrable return to the clinician. Furthermore, should we wish to focus on parameters that may increase the reliability of our diagnosis of bacterial meningitis beyond those readily available, other determinations should be considered in a large prospective study including lactic acid dehydrogenase, creatinine phosphokinase BB, phosphohexose isomerase, etc.4 Only after such studies can we address the true value of lactic acid in assisting in the differential diagnosis of meningitis.
*Supported in part by Grant #RR-69, Division of Research Resources, National Institutes of Health.
Roger Barkin, MD JEM Section Editor, Clinical Pediatrics
REFERENCES 1. Nanji AA, Whitlow KJ: Clinical utility of lactic acid measurement in body fluids other than plasma. J Emerg Med 1984; 1521-526.
2. Gastrin B, Briem H, Rombo L: Rapid diagnosis of meningitis with use of selected clinical data and gas liquid chromatographic determination of lactate
553
554
concentration in cerebrospinal fluid. J Infect Dis 1979; 139529. 3. Controni G, Rodriquex WJ, Hicks JM, et al: Cerebrospinal fluid lactic acid levels in meningitis. J Pediatr 1971; 91~379.
The Journal of Emergency Medicine
4. Jakoby RK, Jakoby WB: Lactic dehydrogenase of
cerebrospinal fluid in the differential diagnosis of cerebrovascular disease and brain tumor. J Neurosurg 1958; 15:45.