CSF Analysis in Bacterial versus a Septic Meningitis
Search Strategy: You search the bibliography of Rosen’s and Roberts & Hedges, only to find numerous dated references circa the 1980’s. Asking around, one of your colleagues provides you with an interesting narrative review from the Canadian Journal of Emergency Medicine (Graham TP, Myth: CSF Analysis Can Differentiate Bacterial Meningitis from Aseptic meningitis, CJEM 2003; 5: 348-349) on this very topic.
Recognizing that CJEM is not MEDLINE accessible and therefore does not show up on Web of Science reviews, you turn to the bibliography of Graham’s narrative review and locate one of the following articles. You next do a search on OVID, but yield an incomprehensibly long list of over 2000 references so you decide to search the term meningitis through the various EM journals and obtain the Academic EM reference below.
Finally, you scour the bibliography of this Academic EM selection to find the Nigrovic article and perform a Web of Science review of the Nigrovic article to obtain the Bonsu article. Note that all of these articles deal with children because you are unable to locate any recent study in adults to answer your PICO question.
Working overnights (again) you face the dilemma of performing yet another lumbar puncture on a febrile 37-year old female with a non-specific, severe headache and fever of 18-hours duration. She has no past medical history, no HIV-risk factors, and has not traveled outside of the St. Louis vicinity for over two years. Her temperature is 39.7° Celsius and she has a heart rate of 110, but no appreciable photophobia or neck stiffness and no other clinically apparent source for her fever. She has no focal neurological deficits and you do not appreciate any “jolt accentuation” of her headache. Your hopes of finding an obvious source for the fever were dashed with an unremarkable chest x-ray and urinalysis. Recognizing the necessity of excluding meningitis, you once again explain to the concerned patient and her family of the need to exclude a CNS infection as the source of today’s symptoms. She reluctantly consents to the procedure and her cerebral spinal fluid (CSF) appears clear and colorless.
Chalking this case up to another case of “viral syndrome”, you are surprised when the lab results subsequently indicate a pleocytosis and protein elevation on the CSF with 450 white blood cells (60% neutrophils) and protein 120 mg/dL. The CSF gram stain shows many PMN’s without any appreciable organisms. Given her non-toxic clinical appearance, you feel comfortable that these constellation of symptoms represent aseptic meningitis, but you are uncertain as to the clinical utility of the CSF in clearly distinguishing viral (and other forms of aseptic meningitis) from bacterial meningitis and what the most appropriate management is for this well-appearing patient, so you turn to the medical literature.
First years: Cerebrospinal Fluid Findings in Aseptic Versus Bacterial Meningitis. Pediatrics 2000; 105: 316-319.
Second years: Accuracy and Test Characteristics of Ancillary Tests of Cerebrospinal Fluid for Predicting Acute Bacterial Meningitis in Children with Low White Blood Cell Counts in Cerebrospinal Fluid. Acad EM 2005; 12: 303-309.
Third years: Development and Validation of a Multivariable Predictive Model to Distinguish Bacterial from Aseptic Meningitis in Children in the Post-Haemophilus influenza Era. Pediatrics 2002; 110: 712-719.
Fourth years: Differentiating Acute Bacterial Meningitis from Acute Viral Meningitis Among Children with Cerebrospinal Fluid Pleocytosis: A Multivariable Regression Model. Ped ID Journal 2004; 23: 511-517.
First, Second Year Residents: use the Diagnosis Critical Review Form
Third, Fourth Year Residents: use the Clinical Decision Rule Critical Review Form
Article 1: CSF Findings in Aseptic Versus Bacterial Meningitis, Pediatrics 2000; 105; 316-319
Article 2: Accuracy and Test Characteristics of Ancillary Tests of CSF for Predicting Acute Bacterial Meningitis in Children with Low WBC Counts in CSF, Acad EM 2005; 12: 303-309
Article 3: Development and Validation of a Multivariable Predictive Model to Distinguish Bacterial from Aseptic Meningitis in Children, Pediatrics 2002; 110: 712-719
Article 4: Differentiating Acute Bacterial Meningitis from Acute Viral Meningitis Among Children with Cerebrospinal Fluid Pleocytosis: A Multivariable Regression Model, Ped ID Journal 2004; 23: 511-517