Archive for April 2, 2019

Microscopic Examination and Broth Culture of Cerebrospinal Fluid in Diagnosis of Meningitis

Journal of Clinical Microbiology June 1998 V.36 N.6 P.1617-1620

Dunbar SA et al

We reviewed the results of microscopic Gram stain examination and routine culture for 2,635 cerebrospinal fluid (CSF) samples processed in an adult hospital microbiology laboratory during 55 months. There were 56 instances of bacterial or fungal meningitis (16 associated with central nervous system [CNS] shunt infection), four infections adjacent to the subarachnoid space, four cases of sepsis without meningitis, and an additional 220 CSF specimens with positive cultures in which the organism isolated was judged to be a contaminant. Because 121 of these contaminants were isolated in broth only, elimination of the broth culture would decrease unnecessary work. However, 25% of the meningitis associated with CNS shunts would have been missed by this practice. The most common cause of meningitis was Cryptococcus neoformans, followed by Streptococcus pneumoniaeand Neisseria meningitidis. In 48 of 56 (88%) of cases, examination of the Gram-stained specimen revealed the causative organism. If patients who had received effective antimicrobial therapy prior to lumbar puncture are excluded, the CSF Gram stain is 92% sensitive. Microscopic examination incorrectly suggested the presence of organisms in only 3 of 2,635 (0.1%) CSF examinations. Thus, microscopic examination of Gram-stained, concentrated CSF is highly sensitive and specific in early diagnosis of bacterial or fungal meningitis.

Bacterial meningitis is a life-threatening infection. Although patients typically present with fever, headache, stiff neck, and altered mental status, these symptoms may be subtle in elderly or immunocompromised persons (1, 6, 7,18). Early implementation of appropriate antimicrobial therapy requires prompt identification of the infecting pathogen. Although culture is considered to be the definitive diagnostic test, microscopic examination of a Gram-stained specimen of cerebrospinal fluid (CSF) may provide immediate information about the causative microorganism. Previous studies have suggested that the sensitivity of this technique ranges from 60 to 90% and the specificity approaches 100% (1, 5,6, 8, 12, 18). Scheld concludes that the overall sensitivity is only 75% (14). It is often unclear whether earlier studies have stratified patients based upon their having received prior antimicrobial therapy. Further, the role of semiquantitative assessment of leukocytes (WBC) by microscopic examination as an indicator of infection (8, 12) is uncertain. The value of using broth culture in various populations is also questionable (9, 10,17). In the present study, we reviewed the results of microscopic examination and routine culture of 2,635 CSF specimens to establish the predictive value of the cytocentrifuged Gram stain and the usefulness of broth culture in a veteran population.

FULL TEXT

https://jcm.asm.org/content/36/6/1617

PDF

https://jcm.asm.org/content/jcm/36/6/1617.full.pdf

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April 2, 2019 at 6:15 pm

Predictive Value of Cerebrospinal Fluid (CSF) Lactate Level vs CSF-Blood Glucose Ratio for the Diagnosis of Bacterial Meningitis Following Neurosurgery

Clinical Infectious Diseases July 1999 V.29 N.1 P.69-74

Stephen L. Leib; Remy Boscacci; Othmar Gratzl; Werner Zimmerli

The value of cerebrospinal fluid (CSF) lactate level and CSF/blood glucose ratio for the identification of bacterial meningitis following neurosurgery was assessed in a retrospective study. During a 3-year period, 73 patients fulfilled the inclusion criteria and could be grouped by preset criteria in one of three categories: proven bacterial meningitis (n = 12), presumed bacterial meningitis (n = 14), and nonbacterial meningeal syndrome (n = 47). Of 73 patients analyzed, 45% were treated with antibiotics and 33% with steroids at the time of first lumbar puncture. CSF lactate values (cutoff, 4 mmol/L), in comparison with CSF/blood glucose ratios (cutoff, 0.4), were associated with higher sensitivity (0.88 vs. 0.77), specificity (0.98 vs. 0.87), and positive (0.96 vs. 0.77) and negative (0.94 vs. 0.87) predictive values. In conclusion, determination of the CSF lactate value is a quick, sensitive, and specific test to identify patients with bacterial meningitis after neurosurgery.

FULL TEXT

https://academic.oup.com/cid/article/29/1/69/323396

PDF (CLIC en PDF)

April 2, 2019 at 6:13 pm

Characterization of Chemical Meningitis after Neurological Surgery

Clinical Infectious Diseases January 2001 V.32 N.2 P.179-185

Pierre Forgacs; Carl A. Geyer; Stephen R. Freidberg

We reviewed the records of 70 consecutive adult patients with meningitis after a neurosurgical procedure, to determine the characteristics that might help to distinguish a sterile postoperative chemical meningitis from bacterial infection. The spinal fluid profiles in bacterial and chemical meningitis are similar. The exceptions are that a spinal fluid white blood cell count >7500/µL (7500 × 106/L) and a glucose level of <10 mg/dL were not found in any case of chemical meningitis. The clinical setting and clinical manifestations were distinct enough that no antibiotic was administered after lumbar puncture to 30 (43%) of the 70 patients with postoperative meningitis. Chemical meningitis was infrequent after surgery involving the spine and sinuses. Patients with chemical meningitis did not have purulent wound drainage or significant wound erythema or tenderness, coma, new focal neurological findings, or onset of a new seizure disorder. They rarely had temperatures >39.4°C or cerebrospinal fluid rhinorrhea or otorrhea.

FULL TEXT

https://academic.oup.com/cid/article/32/2/179/319157

PDF (CLIC en PDF)

April 2, 2019 at 6:10 pm

Meningitis postquirúrgica. Características diferenciales de la meningitis aséptica post-quirúrgica

Neurocirugía ABRIL 2009 V.20 N.2

Ramos-Martínez; T. de las Heras-Carballo; C. Fernández-Mateos*; L. de Reina*; T. Álvarez de Espejo-Montiel; N. Escamilla-Fernández; I. Sánchez-Romero** e I. Millán***

Servicios de Medicina Interna (Unidad de Infecciosas) Neurocirugía* y Microbiología**. Sección de Bioestadística***. Hospital Universitario Puerta de Hierro. Madrid.

Introducción

La meningitis postquirúrgica es una complicación infrecuente que se acompaña de un incremento de la estancia hospitalaria y de una elevada mortalidad. Algunos de estos casos no son debidos a una verdadera infección sino a una inflamación aséptica de las meninges denominada meningitis aséptica post-quirúrgica (MAPQ). La adecuada identificación de estos casos permitiría una mejor utilización de los fármacos antimicrobianos.

Material y métodos

Estudio retrospectivo de los pacientes con meningitis postquirúrgica en un hospital terciario durante 14 años comparando las características clínicas de los pacientes con meningitis bacteriana postquirúrgica (MBP) frente a las de pacientes con MAPQ

Resultados

Durante el período analizado se identificaron 35 pacientes (71%) con MBP y 14 pacientes (29%) con MAPQ. La edad media de los pacientes con MBP fue similar a la de los pacientes con MAPQ. Hubo predominio de varones en el grupo de MBP (71%) en relación con los pacientes con MAPQ (36%, p=0,020). La proporción de pacientes con hemorragia intracraneal tendió a ser más frecuente en pacientes que posteriormente desarrollaron MAPQ (9 pacientes, 64 %) que en los pacientes con MBP (12 casos, 34%, p=0,055). Los pacientes sometidos a craneotomía posterior (p=0,092) y los que recibían tratamiento esteroideo (p=0,051) mostraron una mayor tendencia a padecer MAPQ. Siete pacientes MBP (20%) presentaron un recuento celular superior a 5000 células/mm3 en el LCR, cifra no encontrada en ningún caso de MAPQ. No se detectaron diferencias en la glucorraquia y proteinorraquia entre ambos grupos. La bacterias más frecuentemente aisladas fueron Staphylococcus coagulasa negativa y S. aureus. En 5 pacientes (14%) se aislaron bacilos gramnegativos no fermentadores (Pseudomonas aeruginosa y Acinetobacter spp). No hubo ningún fallecimiento atribuido a meningitis postquirúrgica.

Conclusión

Los pacientes sometidos a neurocirugía que fueron ingresados por hemorragia cerebral, intervenidos de la fosa posterior o tratados con esteroides presentan una mayor tendencia a presentar MAPQ. Los recuentos celulares en LCR elevados (superiores a 5000 células /mm3) sugieren la existencia de MBP.

PDF

http://scielo.isciii.es/pdf/neuro/v20n2/2.pdf

April 2, 2019 at 6:08 pm


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