Laboratory Tests 41718

• CSF examination via lumbar puncture (LP, spinal tap); contraindicated in patients with cardiorespiratory compromise, increased intracranial pressure and papille-dema, focal neurologic signs, seizures, bleeding disorders, abnormal level of consciousness, and possible brain herniation (a CT scan should be performed before LP if there is a question of a CNS mass to avoid potential for brain herniation) (see Table 70-2 for specific CSF findings)

• Elevated opening pressure (may be decreased in neonates, infants, and children)

• Decreased glucose

• Elevated protein

• Elevated WBC (differential provides clues to offending pathogen)

• Gram stain (adequate for diagnosis in 60-90% of patients with bacterial meningitis)

• Culture and sensitivity (positive in 70-85% without prior antibiotic therapy, positive in less than 20% who have had prior therapy)

• If CSF Gram stain and/or culture is negative, rapid diagnostic tests (such as latex agglutination) may be useful; these tests are positive even if bacteria are dead

• Polymerase chain reaction (PCR; DNA amplification of the most common bacterial meningitis pathogens) may be useful to help exclude bacterial meningitis

• Elevated CSF lactate and C-reactive protein

• Blood cultures (at least two cultures, one "set"; positive in 66%)

• Scraping of skin lesions (such as rash) for direct microscopic examination and culture

• Other cultures should be obtained as clinically indicated (such as sputum)

• WBC with differential

• Fungal meningitis: CSF culture, CSF and serum cryptococcal antigen titers, microscopic examination of CSF specimens

• Tuberculous meningitis: CSF culture, PCR evaluation (preferred), and acid-fast stain

The Prevention and Treatment of Headaches

The Prevention and Treatment of Headaches

Are Constant Headaches Making Your Life Stressful? Discover Proven Methods For Eliminating Even The Most Powerful Of Headaches, It’s Easier Than You Think… Stop Chronic Migraine Pain and Tension Headaches From Destroying Your Life… Proven steps anyone can take to overcome even the worst chronic head pain…

Get My Free Audio Book


Post a comment