Acute bacterial meningitis: Adults

Transcription

1 Acute bacterial meningitis: Adults Diagnosis CSF findings: o White blood cell count (neutrophil/lymphocyte predominance) and protein concentration are elevated o Opening pressure mm h 2 o o Glucose concentration may be low Rapid diagnostic tests like o Gram stain examination is recommended: accurate in 60 to 90% fast, inexpensive, and o Polymerase Chain Reaction (PCR) is useful for excluding a diagnosis of bacterial meningitis o Latex agglutination, while quick, simple, and sensitive, however negative test cannot rule out. Results most useful for patients who have begun therapy and have negative Gram stain and CSF culture. o Lactate concentration: not recommended, however >4.0nmol/L in postop neurosurgical patients is an indication for empirical therapy Clinical suspicion for bacterial meningitis is high but CSF negative perform o PCR for enteroviruses: higher sensitivity and faster than viral culture o CRP: normal levels have high negative predictive value for bacterial meningitis Procalcitonin is useful, but not recommended as not widely available Initial Management Steps (see figure 1) Bacterial meningitis is a neurologic emergency; progression to more severe disease reduces the patient s likelihood of a full recovery. Blood culture & lumbar puncture should be performed immediately. CT before LP in all patients

2 Fig: Algorithm for management of acute meningitis Suspicion of bacterial meningitits CT head, blood cultures STAT LP stat if no contraindications on CT Dexamethasone followed in 15-30mins by empiric antibiotics (to be given even if LP is delayed ) Targeted antibiotics based on culture or gram stain for the recommended duration. Empiric therapy Choice of agents for empiric therapy should be determined by the patient s age and the presence of predisposing conditions, and should assume antimicrobial resistance. See table. Should not be delayed >3 hours of first contact with patient Petechial rash if present: Suspected meningococcal infection-->penicillin drug of choice; if penicillin allergy then desensitization.

3 Table: Choice of empirical therapy Predisposing conditions Pathogens Antibiotic recommendation Age 2-50yrs N. Meningitidis, S. Pneumoniae >50 yrs S. pneumoniae, N. meningitidis, L. monocytogenes, Head trauma aerobic gram-negative Basilar skull fracture S. pneumoniae, H. influenzae, group A, b-hemolytic streptococci Vanco+ceftriaxone/cefotaxi me Vanoc+ceftriaxone/cefotaxi me+ampicillin Vanco+ceftriaxone/cefotaxi me Penetrating head trauma Staphylococcus aureus, coagulase-negative staphylococci (especially Staphylococcus epidermidis), aerobic gram-negative Pseudomonas aeruginosa) (including Post neurosurgery Aerobic gram-negative (including P. Aeruginosa), S. aureus, coagulase-negative staphylococci (especially S. epidermidis CSF shunt Coagulase-negative staphylococci (especially S. epidermidis), S. aureus, aerobic gram-negative

4 (including P. aeruginosa), Propionibacterium acnes Management Targeted antimicrobial therapy can begin in adults following a positive CSF Gram stain result; continue empirical therapy if gram stain is negative. Duration of therapy (minimum) o Pathogen not known: 14 days o Neisseria meningitidis or H. Influenzae: 7 days; o S. pneumoniae: 14 days o Streptococcus agalactiae: 21 days o Aerobic gram-negative : 21 days o Listeria monocytogenes: 21 days Therapy is with IV medications through-out. No response within 48 hours-->repeat CSF analysis especially if resistant strains are involved and/or dexamethasone is used. Meningitis with shunt in situ o Removal+appropriate antibiotic: therapy of choice o Reshunting can be done 3 rd day if infection is due to S. Epidermidis and CSF after removal is normal After 7d of antibiotics if after removal some CSF abnormalities present provided protein <200 After 10 serial cultures are sterile if S. Aureus d of antibiotics and 3 days off antibiotics with normal CSF if due to gram negative Outpatient therapy for antibiotic completion can be considered if continuation of IV medications is possible and Inpatient antimicrobial therapy for >6days No fever for at least 24 to 48 hours

5 No significant neurologic dysfunction, focal findings, or seizure activity Stable or improving condition Ability to take fluids by mouth Safe environment with access to a telephone, a refrigerator, food, utilities, and home health nursing Reliable intravenous line and infusion device, if necessary; physician available daily Established plan for physician and nurse visits, laboratory monitoring, and emergencies. References: 1. Tunkel AR, Hartman BJ, Kaplan SL, Kaufman BA, Roos KL, Scheld WM, Whitley RJ. Practice guidelines for the management of bacterial meningitis. CID 2004; Bamberger DM Diagnosis, initial management and prevention of meningitis. AAFP 2010; 82(12): Smith L. Management of bacterial meningitis: New guidelines from IDSA. AAFP 2005; 71(10): Chaudhuri A, Martinez-Martin P, Kennedy PG, Seaton AR, Portegies P, Bojar M, Steiner I; EFNS task force. EFNS guideline on management of community acquired bacterial meningitis: report of an EFNS task force on acute bacterial meningitis in older children and adults. Eur J Neurol. 2008; 15(7):