Meningitis
Revision as of 06:14, 12 March 2011 by Rossdonaldson1 (talk | contribs)
Classification
- Acute (<24 hrs): usually bacterial in origin (25%)
- Subacute (1-7 days): viral or bacterial
- Chronic (>7 days): viral, TB, syphilis, fungi, carcinomatous
Risk Factors
- Age >60 or <5
- Immunosuppressed/Immunocompromised (DM, adrenal insufficiency, HIV, cystic fibrosis, pts on steroids, Sickle Cell, etc)
- Crowding (military, dormitory)
- Alcoholism/cirrhosis
- Recent exposure to someone with meningitis
- Contiguous infection/ dural defect (traumatic, surgical (VP shunt))
- IVDA/endocarditis
- Malignancy
Signs/Symptoms
- Headache
- Nuchal rigidity (may not be present in those with AMS)
- Fevers/chills
- Photophobia
- Vomiting
- Prodromal URI
- Focal neuro sx (ie seizure)
- AMS (may be the only complaint esp in elderly)
Physical Exam Findings
- Signs of Meningeal Irritation:
- Kernigs: passive knee extension while pt is supine causes neck pain and hamstring resistanc
- Brudzinski: when you flex pts neck you see involuntary flexion of b/l lower ext
- Fever
- Rash
- Abnl Neuro exam (altered, focal cranial nerve defect)
- papilledema
Differential Diagnosis
- encephalitis
- brain mass
- brain abscess
- subarachnoid hemorrhage
- migraine
Orders/Workup
- isolation of patient (if suspect bacterial meningitis)
- cbc
- blood cultures
- coags
- chem panel
- CT head
- CXR (50% of pts w/pneumoccocal meningitis have e/o pna on CXR)
- CSF studies
- Glucose and protein (Tube 1)
- Gram stain and culture (Tube 2)
- Cell count and differential (Tube 3)
- Special studies if indicated (e.g. HSV PCR or india ink in HIV pt) - Tube 2
Interpreting CSF
| Bacterial | Viral | Fungal | Neoplastic | |
| Opening Pressure | ↑↑ | Normal, mild ↑ | Normal, mild ↑ | Normal, mild ↑ |
| Cell Cnt | >1000 | <1000 | <500 | <500 |
| % PMNs | >80% | 1-50% | 1-50% | 1-50% |
| Glucose | <40 | >40 | <40 | <40 |
| Protein | >200 | <200 | >200 | >200 |
| Gram stain | + (80% effective) | neg | AFB, India ink |
Treatment
Goal is to initiate treatment within 30 minutes of presentation (if pt is acutely ill). Abx given 2 hr prior to LP will NOT decrease the sensitivity of CSF culture
Antibiotics
- Neonates: Ampicillin + cefotaxime or amp +gent
- Infants(3 mo): Ampicillin + Cefotax or Ceftriaxone
- Children: Cefotax or Ceftriaxone
- Adults: Cefotaxime or ceftriaxone + vanco; Add Ampicillin if Listeria suspected
Steroids*
(Dexamethasone 0.15mg/kg Q6hrsx4dys; 10mg max) --give 15-20 minutes before antibiotics
Neonates (<6wks) --> No
Infants/child --> Yes
Adults --> Yes
*prior to or with abx = only group w/ benefit
PROPHYLAXIS
(N. meningit)
*Rx primary caregivers (those in close contact to nasopharyngeal secretions or those who were with the patient at least 4 hours during week before onset of symptoms)
Cipro 500mg PO x 1 or rifampin x 4 doses or ceftriaxone x1
