Infectious Diseases in Critical Care Medicine

(ff) #1

The use of steroids as an adjunctive measure to treat ABM remains controversial.
Steroids have long been used together with antituberculous therapy in acute tuberculous
meningitis, but there is relatively little information on the use of steroids in the treatment of
ABM in adults. Steroids have been shown to be beneficial in the treatment of meningitis in
children due toH. influenzae, but have been limited toH. influenzae. Because steroids affect
blood/brain barrier permeability, if used steroids should be given after antimicrobial therapy
has been initiated (46–50).


REPEAT LUMBAR PUNCTURE
The diagnosis of ABM rests on analysis of the CSF and demonstration of the putative organism
in the CSF by Gram stain or culture. Corroborative evidence includes a PMN predominance in
the CSF, a decreased CSF glucose, and a highly increased CSF lactic acid level. A repeat lumbar
puncture is indicated if the patient has not responded to therapy within 72 hours. If the
antibiotic is ineffective, the CFS profile will remain relatively unchanged and most
importantly, the CSF lactic acid levels will have not decreased. CSF lactic acid levels decrease
rapidly with appropriate antimicrobial therapy and CSF glucose levels also quickly return to
normal. If the patient is clinically not responding to antimicrobial therapy and the repeat
lumbar puncture shows the same or only slightly increased CSF glucose levels with the same
or only slightly decreased lactic acid levels, then the clinician should reassess the antimicrobial
regimen (1,5,30–33,45).
Reevaluation of the antibiotic should include a reassessment of its spectrum, degree of
activity, dosage, CSF penetration, to determine if a change in therapy is warranted. The only
CNS infection that may present with ABM that would change quickly as the result of
appropriate therapy would be a brain abscess that has ruptured into the ventricular system.
Such a large number of organisms released from the brain abscess into the CSF would be
overwhelming to the host and in spite of appropriate antimicrobial therapy, would not change
the CSF parameters within three days without drainage of the brain abscess. There is no need
to repeat the lumbar puncture if the patient is responding to therapy, suggesting that the
proper antibiotic has been chosen and given in the correct dose, and that it is effectively cidal at
CNS concentrations resulting in a rapid clinical response as well as a rapid response to the key
CSF parameters of the lactic acid/CSF glucose (1–5,45,53).


REFERENCES



  1. Schlossberg D. Infections of the Nervous System. New York: Springer-Verlag, 1990.

  2. Scheld WM, Whitley RJ, Durack DT. Infections of the Central Nervous System. New York: Raven
    Press, 1991.

  3. Tunkel AR. Bacterial Meningitis. Philadelphia: Lippincott Williams & Wilkins, 2001.

  4. Roos KL. Central Nervous System Infectious Diseases and Therapy. New York: Marcel Dekker Inc.,
    1997.

  5. Wood M, Anderson M. Neurologic Infections. London: W.B. Saunders, 1988.

  6. Quagliarello V, Scheld WM. Bacterial meningitis: pathogenesis, pathophysiology, and progress.
    N Engl J Med 1992; 327:864–872.

  7. Thomas K, Hasbun R, Jekel J, et al. The diagnostic accuracy of Kernig’s and Brudzinski’s signs in a
    prospective cohort of adults with suspected meningitis. Clin Infect Dis 2002; 35:46–52.

  8. Attia J, Hatala R, Cook DJ, et al. Does this adult patient have acute meningitis? JAMA 1999; 282:
    175–181.

  9. Swartz MN. Bacterial meningitis: a view of the past 90 years. N Engl J Med 2004; 351:1826–1828.

  10. Tunkel AR, Hartman BJ, Kaplan SL. Practical guidelines for the management of bacterial meningitis.
    Clin Infect Dis 2004; 39:1267–1284.

  11. Spanos A, Harrell FE Jr, Durack DT. Differential diagnosis of acute meningitis. An analysis of the
    predictive value of initial observation. JAMA 1989; 262:2700–2707.

  12. Short WR, Tunkel AR. Changing epidemiology of bacterial meningitis in the United States. Curr Infect
    Dis Rep 2000; 2:327–331.

  13. Logan SA, MacMahon E. Viral meningitis. B Med J 2008; 336:36–40.

  14. Eisenstein L, Calio F, Cunha BA. Herpes simplex virus type 1 (HSV-1) aseptic meningitis. Heart Lung
    2004; 33:196–197.

  15. Hasbun R. The acute aseptic meningitis syndrome. Curr Infect Dis Rep 2000; 2:345–351.

  16. Chaudry HJ, Cunha BA. Drug-induced aseptic meningitis. Postgrad Med 1991; 90:65–70.


150 Cunha and Smith

Free download pdf