Spinal epidural empyema
Dariusz J. Jaskólski
A spinal epidural empyema is a collection of pus between the bone and dura. It may be a sequela of discitis or vertebral body osteomyelitis but much more frequently it arises as a result of hematogenous spread, usually from urinary tract infection, endocarditis or pneumonia. Male to female ratio is two and patients are typically over 30 years old. Risk factors are as follows: the use of intravenous drugs, immunosuppression, diabetes mellitus, alcohol abuse, foci of infection, open spinal trauma, spinal surgery. The source of infection remains unidentified in <40% of patients. The pathognomonic triad of symptoms is: fever, focal back pain aggravated on palpation and progressive neurological deficit. Early diagnosis is crucial since treatment may prevent neurological sequelae but should they appear, cannot warrant their subsidence. The correct diagnosis requires radiological studies, preferably MRI. The management involves surgical drainage of pus and long-standing treatment with antibiotics. The operative procedure aims for decompression of neural elements, meticulous evacuation of both pus and inflammatory granuloma, and obtaining samples for Gram stain and culture assessment. Mortality rate reaches 16%. Factors that influence prognosis in a negative way are: comorbidities, multiple spinal surgical procedures, empyema located in thoracic segment, MRSA infection.