By Stan Deresinski, MD, FACP, FIDSA
Clinical Professor of Medicine, Stanford University
Dr. Deresinski reports no financial relationships relevant to this field of study.
SYNOPSIS: Non-operative management of spinal epidural abscess is safe and effective in selected patients.
SOURCE: Vakili M, Crum-Cianflone NF. Spinal epidural abscess: A series of 101 cases. Am J Med 2017;130:1458-1463.
Vakili and Crum-Cianflone reviewed the case records of 101 patients with spinal epidural abscess seen at a single hospital in San Diego between 2004 and 2014. The incidence during this time was 5.1 per 10,000 admissions. The most frequently encountered comorbid risk factor was diabetes mellitus, which was present in approximately one-fourth of cases. Additional risk factors included injection drug use in 16.8% and alcoholism in 14.9%, while 19.8% had undergone spinal surgery, 11.8% had suffered spinal trauma, and 6% had received a local injection; 26% had bacteremia.
Only eight (7.9%) of the patients presented with all three elements of the “classic triad” of spinal pain, fever, and neurologic deficit, with 47% presenting with only local pain and tenderness (stage 1). Radicular pain (stage 2) was present in 22%, while 11% had sensory, motor, bowel, and/or bladder dysfunction (stage 3). Paralysis (stage 4) was seen at presentation in 9% of cases.
Among the patients in whom a pathogen was identified, 59.4% of the infections were due to Staphylococcus aureus, 13.9% were caused by other Gram-positive coccal organisms, and 4.9% were due to aerobic Gram-negative bacilli. All patients received intravenous antibiotics, which were administered for a median duration of eight weeks. Of the entire cohort, 27% underwent a drainage procedure performed by an interventional radiologist (IR) and 47% underwent operative surgical drainage (three patients among this group subsequently required IR drainage). The remaining 27% underwent no invasive procedure and were treated with antibiotics alone.
At discharge, none of the 47 patients with a stage 1 presentation had evidence of paralysis, while this was present in 1/22 and 1/11 of those with stage 2 and 3 presentations, respectively. Six of nine patients with paralysis at presentation still demonstrated evidence of paralysis at discharge; seven of the nine had undergone surgery. No patient who underwent IR drainage alone and none who did not receive a drainage procedure were paralyzed at discharge. Seven patients, all with Staphylococcus aureus infection, died.
Over the last decade, there has been an evolution toward the non-operative management of selected patients with spinal epidural abscess. This retrospective cohort study validates this approach. In this study by Vakili and Crum-Cianflone, 27% did not undergo surgery and another 27% had only IR drainage — none of these patients had evidence of paralysis at hospital discharge.
Patients in this cohort received antibiotics for a median duration of eight weeks. Whether this is the appropriate duration of therapy is unknown and, in my opinion, is likely to be longer than necessary in most cases.
The key to a favorable outcome is early diagnosis and therapy. Unfortunately, the diagnosis often may be delayed. In a recent review, a national Veterans Administration study found evidence of diagnostic error in 66/119 (55.5%) patients with spinal epidural abscess.1 These errors were associated with a significant prolongation in the median time to diagnosis, which was 12 days in those whose evaluation included an error and only four days in those without error. This is critical in many patients since it is generally agreed that surgical intervention must be performed within approximately 48 hours after the onset of paralysis to have a reasonable chance of its reversal.
- Bhise V, Meyer AND, Singh H, et al. Errors in diagnosis of spinal epidural abscesses in the era of electronic health records. Am J Med 2017;130:975-981.