Epidural Abcess

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

Mechanism of Damage Direct compression Direct compression Thrombosis and thrombophlebitis of nearby veins Thrombosis and thrombophlebitis of nearby veins Interruption of the arterial blood supply Interruption of the arterial blood supply Focal vasculitis Focal vasculitis Bacterial toxins and mediators of inflammation Bacterial toxins and mediators of inflammation

Epidemiology Incidence- 25/100,000 hospital admissions Incidence- 25/100,000 hospital admissions 0.5-3% of patients with long term epidural catheters 0.5-3% of patients with long term epidural catheters

Microbiology Staphylococcus aureus — 63 percent Staphylococcus aureus — 63 percent Gram negative bacilli — 16 percent Gram negative bacilli — 16 percent Streptococci — 9 percent Streptococci — 9 percent Coagulase-negative staphylococci — 3 percent, mostly occurring in patients with prior spinal instrumentation Coagulase-negative staphylococci — 3 percent, mostly occurring in patients with prior spinal instrumentation Anaerobes — 2 percent Anaerobes — 2 percent Others — 1 percent Others — 1 percent Unknown — 6 percent Unknown — 6 percent Mycobacteria- excluded in this list, but important in developing nations Mycobacteria- excluded in this list, but important in developing nations

Sources 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 catheters each make up adt’l < 3% UTI, URI, Sepsis, Abdomen, and other catheters each make up adt’l < 3%

Clinical Presentation Classic Triad: Classic Triad: Fever Fever Back Pain Back Pain Neurologic Deficit Neurologic Deficit Progression: Back pain  root pain  motor/sensory/bowel bladder  paralysis Progression: Back pain  root pain  motor/sensory/bowel bladder  paralysis

Delays in Diagnosis 63 SEA patients matched to 126 controls with spine pain 63 SEA patients matched to 126 controls with spine pain Diagnostic delays in 75% of SEA patients. Diagnostic delays in 75% of SEA patients. Residual motor weakness in 45% vs. only 13% of patients without diagnostic delays (p < 0.05). Residual motor weakness in 45% vs. only 13% of patients without diagnostic delays (p < 0.05). “Classic triad" in 13% of SEA patients and 1% of controls during the initial visit (p < 0.01) “Classic triad" in 13% of SEA patients and 1% of controls during the initial visit (p < 0.01) > 1 RF’s in 98% of SEA patients and 21% of controls (p 1 RF’s in 98% of SEA patients and 21% of controls (p < 0.01) RF’s-DM,IVDU, liver disease, renal failure, indwelling catheter, immunocompromised, recent invasive spinal procedure, vertebral fracture, and distant site of infection RF’s-DM,IVDU, liver disease, renal failure, indwelling catheter, immunocompromised, recent invasive spinal procedure, vertebral fracture, and distant site of infection 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):

Imaging

Therapy 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: Nafcillin plus metronidazole plus either cefotaxime or ceftazidime Nafcillin plus metronidazole plus either cefotaxime or ceftazidime Nafcillinmetronidazole cefotaximeceftazidime Nafcillinmetronidazole cefotaximeceftazidime Vancomycin (1 g every 12 hours) can be substituted for nafcillin Vancomycin (1 g every 12 hours) can be substituted for nafcillin Vancomycin Tx X 4-6 W or until improvement on MRI Tx X 4-6 W or until improvement on MRI

Therapy A retrospective analysis of 57 cases tx’d over 14 y in S.Dakota A retrospective analysis of 57 cases tx’d over 14 y in S.Dakota The lumbar region was most frequently involved, and 46% of patients were immunocompromised. Staphylococcus aureus was the most frequently encountered pathogen. The lumbar region was most frequently involved, and 46% of patients were immunocompromised. Staphylococcus aureus was the most frequently encountered pathogen. For 60 treatment courses, management included medical only (25 patients), medical plus computed tomography-guided percutaneous needle aspiration (7 patients), or surgical drainage approaches (28 patients). For 60 treatment courses, management included medical only (25 patients), medical plus computed tomography-guided percutaneous needle aspiration (7 patients), or surgical drainage approaches (28 patients). Prolonged use of antibiotics alone or combined with percutaneous needle drainage yielded clinical outcomes comparable with antibiotics plus surgical intervention, irrespective of patient age, presence of comorbid illness, disease onset, neurologic abnormality at time of presentation, or abscess size. Prolonged use of antibiotics alone or combined with percutaneous needle drainage yielded clinical outcomes comparable with antibiotics plus surgical intervention, irrespective of patient age, presence of comorbid illness, disease onset, neurologic abnormality at time of presentation, or abscess size. 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): 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):

References unless otherwise noted unless otherwise noted