The CSF protein content is almost always elevated in bacterial meningitis (Tables 20-1 and 20-2). Several studies have shown that protein levels are increased at least to some degree in more than 95% of patients, and its absolute value is over 80 mg/dl in more than 80% of patients.2,6,7 Protein values of greater than 1,000 mg/dl, reported in 8% of cases in Merritt and Fremont-Smith's review, were often associated with spinal subarachnoid block.