Epidural abscess medical therapy
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: João André Alves Silva, M.D. [2]
Overview
An epidural abscess is a rare suppurative infection of the central nervous system, a collection of pus localised in the epidural space, lying outside the dura mater, which accounts for less than 2% of focal CNS infections. [1] It may occur in two different places: intracranially or in the spinal canal. Due to the fact that the initial symptoms and clinical characteristics are not always identical and are similar to other diseases, along with the fact that they are both rare conditions, the final diagnosis might be delayed in time. This late diagnosis comes at great cost to the patient, since it is usually accompanied by a bad prognosis and severe complications, with a potential fatal outcome. According to the location of the collection, the abscess may have different origins, different organisms involved, symptoms, evolutions, complications and therapeutical techniques. [2] The treatment of epidural abscess focuses in two main aspects: reduction of the inflammatory mass and eradication of the responsible organism. These goals can be reached through a combination of medical and surgical approaches. An early surgical decompression and drainage, along with an aggressive antibiotic treatment is the ideal procedure to increase the chances of a better outcome.
Medical Therapy
Several studies have reached the conclusion that the best approach to therapy of epidural abscess, either intracranial or spinal, is a combination of surgical drainage along with prolonged systemic antibiotics (6-12 weeks, IV followed by PO). [3] Due to the importance of preoperative neurologic status, along with the unpredictable progression of neurologic impairment, for the neurological outcome of the patient, decompressive laminectomy and debridement of infected tissues, in the case of SEA, and burr hole placement or craniotomy, in the case of IEA, should take place as early as possible. [4][5] However, in certain clinical scenarios, medical therapy may be the only treatment indicated for that particular case, these include:
- decompressive laminectomy declined by the patient
- high operative risk
- paralysis unlikely reversible, due to being present for more than 24 to 36 hours. Sometimes, in these situations emergency laminectomy is still performed, not to restore the lost function, but to treat the abscess and prevent a sepsis episode
- panspinal infection, therefore the laminectomy would be impracticable. In this case, the physician might consider a limited laminectomy or laminotomy with catheter insertion at the top and bottom of the spinal canal, for drainage and irrigation.
There are several reported cases in which patients recovered from epidural abscess, without surgical treatment, following simple diagnostic aspiration with antibiotic therapy. In these patients however, there was no neurologic deficit related to the abscess or it was simply accompanied by minor weakness at initial presentation. [6] Besides the antibiotic therapy, this conservative approach also includes:
- close neurologic monitoring strategy, defined before treatment initiation
- follow-up MRI to evaluate the status of the abscess and confirm its resolution
- immediate surgery, in case of neurologic deterioration.
The indication for a specific antibiotic should be given by the results of blood cultures or a CT-guided aspiration of the abscess. However, until blood culture results are obtained, the patient should be on empirical antibiotic therapy. The efficacy of the antibiotic treatment, as well as its duration, may be determined by monitoring the evolution of the ESR, CRP, pain and function, along with resolution of radiographic changes. [3]
Intracranial Epidural Abscess
The empiric antibiotic therapy for this type of abscess is similar to the one used for subdural empyema and should be continued for 3 to 6 weeks after surgery, or longer in case of osteomyelitis. [7] This should cover: [4]
This regimen must include: [8][3]
- Penicillin with anti-staphylococcal activity or Vancomycin in case of suspicion of MRSA
- Third-generation cephalosporin
- This regimen might also include Metronidazole
Spinal Epidural Abscess
Initial antibiotic therapy for this type of abscess should target staphylococci and aerobic gram negative bacilli, particularly in patients with history of IV drug use or spinal procedures. The treatment should last for a period of 4 to 6 weeks, or longer, up to 8 weeks, in case there is contiguous osteomyelitis. [9] Therefore, the antibiotic regimens for the unknown organism of intracranial epidural abscess may also be applied to the spinal epidural abscess.
Antibiotic Therapy
- Empiric antibiotic therapy of focal CNS Infections:[10]
▸ Click on the following categories to expand treatment regimens.
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Age and Predisposing Factors ▸ Infants < 1 month ▸ Infants 1-3 months ▸ > 3 months Immunocompetent Children; Adults < 55 years ▸ Adults > 55 years; Alcoholics; Debilitating Illness ▸ Specific Situations |
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When the responsible organism has been isolated and identified in cultures, the therapy should be re-directed to this agent. [11]
- Pathogen-based antibiotic therapy of focal CNS Infections: [12]
▸ Click on the following categories to expand treatment regimens.
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Pathogen-Based Therapy ▸ Neisseria meningitidis ▸ Streptococcus pneumoniae ▸ Gram negative bacilli ▸ Pseudomonas aeruginosa ▸ Staphylococci ▸ Listeria monocytogenes ▸ Haemophilus influenzae ▸ Streptococcus agalactiae ▸ Bacteroides fragilis ▸ Fusobacterium spp. |
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Epidural Abscess Drug Summary
Nafcillin and Oxacillin
- Group of narrow spectrum antibiotics, of the penicillin class, both penicillinase-resistant. Their mechanism of action is based on binding transpeptidases, thereby blocking the cross-linkage of peptidoglycan. They are also involved in the activation of autolytic enzymes.
- They are used to treat gram-positive bacteria, particularly staphylococci, however are not indicated in the treatment of MRSA/ORSA.
- They are known to cause hypersensitivity reactions and to interfere with cytochrome P-450. Their use in congestive heart failure and kidney disease patients should also be cautious because of risk of edema.
- The dosage may need to be adjusted in patients suffering from kidney or liver disease.[13]
Vancomycin
- A glycopeptide antibiotic that exerts its activity by inhibiting peptidoglycan synthesis and hence bacterial cell walls. It has bactericidal activity agains most pathogens and bacteriostatic activity agains enterococci.
- A narrow spectrum antibiotic used only for gram-positive bacteria.
- Due to its toxicity (Ototoxicity, Nephrotoxicity and Thrombophlebitis), along with risk of anaphylaxis, Stevens-Johnson syndrome, neutropenia and thrombocytopenia[13], its use is restricted to multidrug-resistant organisms (MRSA/ORSA, Clostridium difficile).
- In recent years, the emergence of vancomycin-resistant pathogens, has increased the use of antibiotics, such as carbapenem and linezolid.
Cephalosporin
- A bactericidal antibiotic, with a similar mechanism of action as other penicillins, cephalosporins interfere with the synthesis of peptidoglycan of the cell wall, being however less susceptible to penicillinases.
- Used for prophylaxis and treatment of certain bacteria.
- There are 4 generations of cephalosporins: 1st generation are indicated for gram-positive bacteria, while 2nd, 3rd and 4th generations have increased activity against gram negative organisms.
- 1st generation cephalosporins include: cefalexin and cefazolin; 2nd generation: cefuroxime and cefoxitin; 3rd generation: ceftriaxone and cefotaxime; and 4th generation: cefepime and cefquinome.
- Organisms not usually covered by cephalosporins include: Listeria, MRSA and Enterococci.
- Possible adverse effects include: nausea, diarrhea, rash, hypersensitivity reactions, vitamin K deficiency and increased nephrotoxicity of aminoglycosides, when given concomitantly.
Metronidazole
- A nitroimidazole antibiotic, bactericidal against anaerobic organisms, with antiprotozoal activity. It acts by forming free radical metabolites within the bacterial cell, which damages the bacterial DNA. When given with clarithromycin and a proton pump inhibitor, is used in the treatment of ''Helicobacter pylori''.
- Used in the treatment of organisms such as: Clostridium difficile, Entamoeba, Trichomonas, Giardia and Gardnerella vaginalis.
- Possible adverse effects include: nausea, diarrhea, headaches, encephalopathy, cerebellar ataxia, neutropenia[13] and association with thrombophlebitis, when administered intravenously.
- Its use may cause darker red urine.
Carbapenem
- Broad spectrum beta-lactam antibiotic, with a structure which protects it from the action of beta-lactamases. Active against gram-positive cocci, gram-negative rods and anaerobic bacteria, with the exception of intracellular organisms. Administered intravenously.
- Examples of carbapenems include imipenem, meropenem and ertapenem.
- The significant side-effects including gastrointestinal problems, rash and CNS toxicity limit its use.
References
- ↑ Longo, Dan L. (Dan Louis) (2012). Harrison's principles of internal medici. New York: McGraw-Hill. ISBN 978-0-07-174889-6.
- ↑ Danner, R. L.; Hartman, B. J. (1987). "Update of Spinal Epidural Abscess: 35 Cases and Review of the Literature". Clinical Infectious Diseases. 9 (2): 265–274. doi:10.1093/clinids/9.2.265. ISSN 1058-4838.
- ↑ 3.0 3.1 3.2 Grewal, S. (2006). "Epidural abscesses". British Journal of Anaesthesia. 96 (3): 292–302. doi:10.1093/bja/ael006. ISSN 0007-0912.
- ↑ 4.0 4.1 Darouiche, Rabih O. (2006). "Spinal Epidural Abscess". New England Journal of Medicine. 355 (19): 2012–2020. doi:10.1056/NEJMra055111. ISSN 0028-4793.
- ↑ Darouiche RO, Hamill RJ, Greenberg SB, Weathers SW, Musher DM (1992). "Bacterial spinal epidural abscess. Review of 43 cases and literature survey". Medicine (Baltimore). 71 (6): 369–85. PMID 1359381.
- ↑ Wheeler D, Keiser P, Rigamonti D, Keay S (1992). "Medical management of spinal epidural abscesses: case report and review". Clin Infect Dis. 15 (1): 22–7. PMID 1617070.
- ↑ Mandell, Gerald L.; Bennett, John E. (John Eugene); Dolin, Raphael. (2010). Mandell, Douglas, and Bennett's principles and practice of infectious disease. Philadelphia, PA: Churchill Livingstone/Elsevier. ISBN 0-443-06839-9.
- ↑ Longo, Dan L. (Dan Louis) (2012). Harrison's principles of internal medici. New York: McGraw-Hill. ISBN 978-0-07-174889-6.
- ↑ Mandell, Gerald L.; Bennett, John E. (John Eugene); Dolin, Raphael. (2010). Mandell, Douglas, and Bennett's principles and practice of infectious disease. Philadelphia, PA: Churchill Livingstone/Elsevier. ISBN 0-443-06839-9.
- ↑ Longo, Dan L. (Dan Louis) (2012). Harrison's principles of internal medici. New York: McGraw-Hill. ISBN 978-0-07-174889-6.
- ↑ Longo, Dan L. (Dan Louis) (2012). Harrison's principles of internal medici. New York: McGraw-Hill. ISBN 978-0-07-174889-6.
- ↑ Longo, Dan L. (Dan Louis) (2012). Harrison's principles of internal medici. New York: McGraw-Hill. ISBN 978-0-07-174889-6.
- ↑ 13.0 13.1 13.2 Greenlee JE (2003). "Subdural Empyema". Curr Treat Options Neurol. 5 (1): 13–22. PMID 12521560.