Epidural AbcessEpidural Abcess

Note: Dura adheres to the skull above the foramen magnum and anteriorly down to L1

Mechanism of DamageMechanism of Damage

Direct compressionDirect compression Thrombosis and thrombophlebitis of Thrombosis and thrombophlebitis of

nearby veinsnearby veins Interruption of the arterial blood Interruption of the arterial blood

supplysupply Focal vasculitisFocal vasculitis Bacterial toxins and mediators of Bacterial toxins and mediators of

inflammationinflammation

EpidemiologyEpidemiology

Incidence- 25/100,000 hospital Incidence- 25/100,000 hospital admissionsadmissions

0.5-3% of patients with long term 0.5-3% of patients with long term epidural cathetersepidural catheters

MicrobiologyMicrobiology

Staphylococcus aureus — 63 percentStaphylococcus aureus — 63 percent Gram negative bacilli — 16 percent Gram negative bacilli — 16 percent Streptococci — 9 percentStreptococci — 9 percent Coagulase-negative staphylococci — 3 Coagulase-negative staphylococci — 3

percent, mostly occurring in patients with percent, mostly occurring in patients with prior spinal instrumentationprior spinal instrumentation

Anaerobes — 2 percentAnaerobes — 2 percent Others — 1 percentOthers — 1 percent Unknown — 6 percentUnknown — 6 percent Mycobacteria- excluded in this list, but Mycobacteria- excluded in this list, but

important in developing nationsimportant in developing nations

Sources of InfectionSources of Infection

No source ID’d- 30 %No source ID’d- 30 %Skin and soft tissue infxn- 22 %Skin and soft tissue infxn- 22 %Spinal surgery- 12 %Spinal surgery- 12 % IVDU 10 %IVDU 10 %Other, including epidural catheters- 8 Other, including epidural catheters- 8

%%Bone or Joint- 7 %Bone or Joint- 7 %UTI, URI, Sepsis, Abdomen, and other UTI, URI, Sepsis, Abdomen, and other

catheters each make up adt’l catheters each make up adt’l < < 3%3%

Clinical PresentationClinical Presentation

Classic Triad:Classic Triad:FeverFeverBack PainBack PainNeurologic DeficitNeurologic Deficit

Progression: Back painProgression: Back pain root pain root pain motor/sensory/bowel bladdermotor/sensory/bowel bladder paralysisparalysis

Delays in DiagnosisDelays in Diagnosis 63 SEA patients matched to 126 controls with 63 SEA patients matched to 126 controls with

spine painspine pain Diagnostic delays in 75% of SEA patients.Diagnostic delays in 75% of SEA patients. Residual motor weakness in 45% vs. only 13% of Residual motor weakness in 45% vs. only 13% of

patients without diagnostic delays (p < 0.05).patients without diagnostic delays (p < 0.05). “ “Classic triad" in 13% of SEA patients and 1% of Classic triad" in 13% of SEA patients and 1% of

controls during the initial visit (p < 0.01)controls during the initial visit (p < 0.01) >> 1 RF’s in 98% of SEA patients and 21% of 1 RF’s in 98% of SEA patients and 21% of

controls (p < 0.01)controls (p < 0.01) RF’s-DM,IVDU, liver disease, renal failure, RF’s-DM,IVDU, liver disease, renal failure,

indwelling catheter, immunocompromised, recent indwelling catheter, immunocompromised, recent invasive spinal procedure, vertebral fracture, and invasive spinal procedure, vertebral fracture, and distant site of infection distant site of infection

The clinical presentation and impact of diagnostic delays on emergency department patients with spinal epidural abscess. The clinical presentation and impact of diagnostic delays on emergency department patients with spinal epidural abscess.

Davis DP; Wold RM; Patel RJ; Tran AJ; Tokhi RN; Chan TC; Vilke GM. J Emerg Med 2004 Apr;26(3):285-91Davis DP; Wold RM; Patel RJ; Tran AJ; Tokhi RN; Chan TC; Vilke GM. J Emerg Med 2004 Apr;26(3):285-91. .

ImagingImaging

TherapyTherapy

Principles:Principles: Reduction of the inflammatory mass Reduction of the inflammatory mass Eradication of the causative organism Eradication of the causative organism

Empiric Abx:Empiric Abx: NafcillinNafcillin plus plus metronidazolemetronidazole plus either plus either

cefotaximecefotaxime or or ceftazidimeceftazidime VancomycinVancomycin (1 g every 12 hours) can be (1 g every 12 hours) can be

substituted for nafcillinsubstituted for nafcillin Tx X 4-6 W or until improvement on MRITx X 4-6 W or until improvement on MRI

TherapyTherapy     A retrospective analysis of 57 cases tx’d over 14 y in A retrospective analysis of 57 cases tx’d over 14 y in

S.DakotaS.Dakota The lumbar region was most frequently involved, and 46% The lumbar region was most frequently involved, and 46%

of patients were immunocompromised. Staphylococcus of patients were immunocompromised. Staphylococcus aureus was the most frequently encountered pathogen.aureus was the most frequently encountered pathogen.

For 60 treatment courses, management included medical For 60 treatment courses, management included medical only (25 patients), medical plus computed tomography-only (25 patients), medical plus computed tomography-guided percutaneous needle aspiration (7 patients), or guided percutaneous needle aspiration (7 patients), or surgical drainage approaches (28 patients).surgical drainage approaches (28 patients).

Prolonged use of antibiotics alone or combined with Prolonged use of antibiotics alone or combined with percutaneous needle drainage yielded clinical outcomes percutaneous needle drainage yielded clinical outcomes comparable with antibiotics plus surgical intervention, comparable with antibiotics plus surgical intervention, irrespective of patient age, presence of comorbid illness, irrespective of patient age, presence of comorbid illness, disease onset, neurologic abnormality at time of disease onset, neurologic abnormality at time of presentation, or abscess size.presentation, or abscess size.

Medical vs surgical management of spinal epidural abscess. Siddiq F; Chowfin A; Tight R; Sahmoun Medical vs surgical management of spinal epidural abscess. Siddiq F; Chowfin A; Tight R; Sahmoun AE; Smeg RA Jr Arch Intern Med 2004 Dec 13-27;164(22):2409-12.AE; Smeg RA Jr Arch Intern Med 2004 Dec 13-27;164(22):2409-12.

ReferencesReferences

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