Patient # 1 = Lab Results Your Results: –CBC: WBC 22 (normal /ul) –BMP: WNL Urine Pregnancy: Neg Head CT: Neg LP: –Cloudy fluid –Opening pressure: 35cm (normal 10 to 25cm) –WBC: 989 (normal <5 per mm3 ) –Tube 1 RBC: 1 (normal <5 per mm3 ) –%PMNs: 85% (normal 0-15%) –% Lymphs 45% (normal >50%) –Glucose 20 (normal >40 mg per dL) –Protein 180 (normal <50 mg per dL ) –Gram stain - positive Diplocci What is your diagnosis? What is your disposition plan? What admission criteria would you use if normal CSF lab analysis ? What if this person had been treated with an antibiotic several days prior to the LP? MSU EM Residency, Lansing MI

Diagnosis & Plan Diagnosis -- Bacterial Meningitis Disposition –Admit ICU –Did you remember to protect the staff with Isolation precautions when you suspected Meningitis? –Is prophylaxis a consideration her family? –Was your choice of Antibiotic appropriate? Admit criteria for normal CSF? –Consider Admit if …. Taking fluids poorly Pain issues can not be addressed at home Partially treated Meningitis? –Consult admitting doctor –Can’t trust LP results

Partially treated Meningitis? Latex agglutination for detection bacterial antigens in CSF –Sensitivity varies greatly between bacteria. H. influenzae has a sensitivity of 60 to 100%, Lower for other bacteria Lower for other bacteria Specificity for LA is very low Specificity for LA is very low May be useful in partially treated meningitis cases where cultures may not yield an organism May be useful in partially treated meningitis cases where cultures may not yield an organism Some experts suggest using LA in cases of suspected bacterial meningitis if the initial Gram stain and bacterial culture are negative after 48 hours. Remember: Cultures of cerebrospinal fluid are still the gold standard for confirming the diagnosis of bacterial meningitis. Cerebrospinal Fluid Analysis D. SEEHUSEN, M.D., M. REEVES, M.D., & D. FOMIN, M.D.

Bacterial Meningitis Etiologic agent: –Neonates Escherichia coli Listeria monocytogenese –Children Haemophilus influenzae –Adult Streptococcus pneumoniae Neisseria meningitidis Pathophysiology –Blood –Direct extension –Traumatic or surgical Risk groups –Complement deficiency –Asplenic –Immunosuppressed –Crowding –Recent neurosurgical intervention

Don’t forget to look for clues: Non-blanching petechiae & cutaneous hemorrhages

Be alert for CSF glucose issues Suspect Bacterial but the glucose isn’t low? –Elevated glucose seen in pt’s with high serum glucose –CSF glucose normally is appx 60% of the serum glucose High CSF glucose but not bacterial meningitis? –No diagnostic significance - spillover from elevated serum Low CSF glucose level –usually is associated with bacterial infection probably due to enzymatic inhibition not bacterial consumption of the glucose –Also is seen in tumor infiltration, Hallmarks of meningeal carcinomatosis