Value of cerebrospinal fluid lactate for the diagnosis of bacterial meningitis in postoperative neurosurgical patients

Objetivo Evaluar el valor diagnóstico del lactato en líquido cefalorraquídeo (LCR) para el diagnóstico de meningitis bacteriana (MB) después de una neurocirugía, y compararlo con otros marcadores bioquímicos del LCR. Métodos Estudio prospectivo de pacientes sometidos a neurocirugía admitidos consecutivamente en la Unidad de Cuidados Intensivos (UCI) del Hospital Maciel. Los pacientes con sospecha clínica de MB, fueron categorizados por criterios predeterminados en tres grupos: (1) MB probada, y (2) MB probable, y (3) MB excluida. Los marcadores de LCR fueron analizados de acuerdo a la curva ROC (receiver operating curve) para evaluar su exactitud diagnóstica. Resultados Se estudiaron 158 pacientes. 46 presentaron sospecha clínica de MB, de los cuales se obtuvieron muestras de LCR mediante realización de punción lumbar: 10 fueron MB probada, 4 fueron MB probable y 32 MB excluida. La media de lactato en LCR fue: 10,72±4,68mM para MB probada, 6,07±0,66mM para MB probable y 3,06±1,11mM para MB excluida (p<0,0001 para MB probada y MB probable vs MB excluida; p=NS para MB probada vs MB probable). El lactato en LCR demostró la mayor exactitud diagnóstica para MB en los 2 escenarios estudiados: (1) cultivo bacteriano o tinción de Gram positivo en LCR como control positivo (sensibilidad: 87%, especificidad: 94%, valor de corte: 5,9mM); y (2) combinación de MB probada y MB probable como control positivo (sensibilidad: 92%, especificidad: 100%, valor de corte: 5,2mM).Conclusión De acuerdo a nuestros resultados, la medición de lactato en LCR es un método diagnóstico rápido, sensible y específico para identificar la necesidad de iniciar antibioterapia en pacientes con sospecha clinica de MB postquirúrgica (AU)

Value of cerebrospinal fluid lactate for the diagnosis of bacterial meningitis in postoperative neurosurgical patients.

OBJECTIVE: To evaluate the diagnostic value of CSF lactate (L(CSF)) for the diagnosis of bacterial meningitis (BM) following neurosurgery, and compare it with other CSF markers. METHODS: Prospective study of consecutive neurosurgical postoperative patients admitted to the Intensive Care Unit (ICU) at Maciel Hospital. Patients with clinical suspicion of BM were categorised, according to preset criteria, into 3 groups: (1) proven BM; (2) probable BM, and (3) excluded BM. CSF markers were plotted in a receiver operating curve (ROC) to evaluate their diagnostic accuracy. RESULTS: The study included 158 patients. We obtained 46 CSF samples from patients with clinical suspicion of BM by lumbar puncture (LP): 10 corresponded to proven BM, 4 to probable BM and 32 to excluded BM. Mean lactate in CSF (L(CSF)) was: 10.72±4.68mM for proven BM, 6.07±0.66mM for probable BM and 3.06±1.11mM for excluded BM (P<.001 for proven BM and probable BM vs excluded BM; P=NS for proven BM vs probable BM). L(CSF) displayed a better diagnostic accuracy for BM in the 2 scenarios studied: (1) positive bacterial CSF culture or Gram stain as positive control (gold standard) (sensitivity: 87%, specificity: 94%, cut-off value: 5.9mM), and (2) combination of proven BM and probable BM as positive control (sensitivity: 92%, specificity: 100%, cut-off value: 5.2mM). CONCLUSIONS: According to our results, determination of L(CSF) is a quick, sensitive and specific test to identify the need for antimicrobial therapy in neurosurgical postoperative patients with clinical suspicion of BM.

Molecular alterations of parotid saliva in infantile chronic recurrent parotitis.

Infantile chronic recurrent parotitis (ICRP) is an insidious disease whose etiopathogenesis remains an enigma. Alterations in the physical appearance of parotid saliva from ICRP patients have been frequently reported. However, sialochemical studies in regard to ICRP are very rare. The aim of this study was to determine whether saliva of ICRP patients presents major physicochemical and biochemical alterations compared with saliva from paired healthy controls. Parotid, whole, and submandibular/sublingual saliva was collected at an asymptomatic stage from 33 ICRP patients (5-16 y old, both sexes) and from 33 sex- and age-matched healthy controls. Saliva was analyzed for protein concentration, mode of protein diffusion on cellulose membranes, unidimensional sodium dodecylsulfate (SDS)-polyacrylamide gel electrophoresis protein profiles and zymographic profiles of metalloproteinase 2 (MMP-2) and metalloproteinase 9 (MMP-9). Parotid saliva of ICRP patients showed an increased protein concentration, altered mode of protein diffusion, a higher frequency of polypeptide bands of 43, 37, 33, 29, 26, 16, and 10 kD, higher asymmetry in the polypeptide profiles of both contralateral parotid saliva, and an increase in the frequency of MMP-2 and MMP-9. Parotid saliva of patients with ICRP is molecularly altered with respect to normal saliva. Some of the molecular differences could be related to the etiopathogenesis of the disease.