C. Investigations: The initial diagnosis of Meningitis is based on the CSF analysis. After the Neonatal period, the normal CSF should have <5 cells per cumm. A glucose level >50% of the serum concentration, a protein level <45mg/dl, and a negative gram stain. In pyogenic meningitis the CSF pressure is increased, the cell count is more than 500/cumm, the glucose level is reduced, the proteins elevated and Gram stain is positive. CBC shows polymorpholeuco-cytosis.
Anaemia may be a feature in H. Influenza meningitis as a result of acute hemolysis. Thrombocytopenia and anaemia may indicate disseminated intravascular coagulation DIC is confirmed by prolonged prothrombin time, partial thromboplastin time, decreased fibrinogen and thrombocytopenia increased in the fibrin split products.
D. Obtain a CT Scan or MRI before performing a lumbar puncture whenever there is a focal deficit, papilledema or cardiovascular instability (generalized cerebral edema or suspected brain abscess).
