Pedia-case-1-management.docx

Diagnostics 1. A complete and detailed history and physical examination with details of length of illness and details of presenting symptoms, preceding illness, past medical history. Also history of exposure: travel, sick contact, insect bites, sexual activities, animal contacts. 2. Initial labs:

CBC, CRP, UA, PCR, LAT, Blood cultures; CSF: with opening pressure, Procalcitonin and serology Cerebrospinal fluid (CSF) culture is the gold standard for the diagnosis of acute bacterial meningitis. CBC should not be used solely as a basis for starting antibiotics. Signs and symptoms of bacterial meningitis associated with neutrophilia and increased serum CRP are highly suggestive of bacterial meningitis. In patients suspected to have bacterial meningitis, blood culture should be performed prior to starting antibiotic therapy. Serum and CSF CRP are useful in confirming and excluding bacterial meningitis. PCR may be utilized to amplify DNA from patients with meningitis caused by common meningeal pathogens (S. pneumonia meningitidis and H. influenzae) especially if the CSF culture is negative. Procalcitonin may be used differentiate bacterial from viral meningitis. In situations wherein a CSF analysis cannot be performed immediately, it may be used as a basis to start antibiotics. However, it should not replace CSF analysis and culture in the diagnosis of bacterial meningitis. Latex agglutination test detects bacterial antigens in the CSF. Studies have shown that the sensitivity of CSF bacterial antigen detection test ranges from 0-25%, and this is for cases where culture results are negative. Initial imaging: CT head without contrast to rule out space-occupying lesions, hemorrhage or trauma. MRI of brain and spine if concern for myelitis/encephalitis. Imaging can be added to evaluate for abscess, inflammation but is not necessarily sensitive to make diagnosis. Cerebral edema is often not demonstrated on scans. Neuroimaging is used to identify the presence of complications of bacterial meningitis

and to rule out contraindications in doing a lumbar tap. Neuroimaging is not used to diagnose the presence or absence of a CNS infection.

CSF cellular parameters in normal individuals and in patients with different types of meningitis

Management 1. Neuro assessment: airway protection for severe altered mental status (GCS below 8). Take precautions for increased intracranial pressure during intubation. Consider ICP monitoring for evidence of elevated ICP. Treat seizure activity: 50% of patients who presented with seizures progress to status epilepticus, which is hard to control and correlates with poor neuro outcomes. 2. Cardiovascular support as needed; cerebral perfusion pressure is directly affected by mean blood pressure.

3. Antibiotics early; do not withhold antibiotics awaiting lumbar puncture. Start antiviral if high suspicion of herpes infection. Electrolyte and fluid derangements are common: 

Diabetes insipidus: monitor urine output and check sodium level for spike in UOP (Na in the 150s-160s).

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SIADH: late onset of electrolyte derangements with oliguria and relative hyponatremia (Na can be below 125), increased risk of seizure activity. Correct hyponatremia acutely to bring Na level above 125 with 3% saline if necessary (seizure threshold), then slow correction to normal level (Na 140-145) over the next 36-48 hrs.

Treatment Ampicillin 50-100 mg/kg Q6 hrs; max 12 gm/day. Vancomycin15-20 mg/kg Q8 hrs; max 1 gm/dose; follow level, adjust dose for renal insufficiency. Gentamycin 2.5 mg/kg Q8 hrs; max 120 mg/dose; follow level, adjust dose with renal insufficiency. Cefotaxime 50 mg/kg Q6 hrs; max 2 gm/dose. Ceftriaxone 100 mg/kg Q24 hrs; max 4 gm/day. Acyclovir10-20 mg/kg Q8 hrs.

Expected response to treatment With appropriate treatment: CSF culture and gram stain will become negative in 24-48 hours, glucose will normalize in 72 hrs. Cell counts and proteins will take days to normalize.

APPENDIX – 1