This is a review of all spinal abscesses at Baystate (total 162), from 2005 – 2015. They compare 88 randomly selected controls whom had similar ICD-codes less the spinal abscess plus an MRI that was negative for acute infectious process.
Interesting take home points, much of which is consistent with prior (albeit scant) literature:
-73% of patients are over age 50.
-more likely to have their second visit (50.6% vs 29.6% of controls) – though this 50.6% of patients with a second visit is surprisingly low for me – no word on how many were sent home from the ED, and had an MRI as an outpatient that were not included in this calculation.; or maybe we’re getting better at finding the needle in the haystack? Or maybe we’re MRI’ing everyone?
-Many received antibiotics within the month: (35.2% vs 6.8% of controls) – this signifies a huge red flag for me. If a patient revisits the ED and recently had pyelo (or anything infectious really), and now presents with back pain, probe a bit more for the possibility of vertebral osteo or discitis.
-percentage of patients with history of IVDA: 20.4% vs 4.6% … this number seems low, but also is somewhat in line with prior studies – thus making me wonder how many I’ve missed…
– percentage of patients with alcoholism with a spinal abscess: 19% vs 8% – the more I get interested in ID, the more I realize that alcoholism is basically a form of immunosuppression.
-percentage of spinal abscess patients with obesity 21.6% vs 2.3%; I’m surprised only 2.3% of controls were obese. Not sure what role this plays as being a diabetic in and of itself was not associated with a higher increased risk in this study.
-fever was present 62.4% in those with a spinal abscess vs 13.6% of those without; this includes self reported fever, which I have to wonder how often we sweep this aside when the patient is afebrile in the ED.
-16% had no identifiable risk factors; a third of the patients presented with back pain, fever, neurologic deficits vs 6%
-Other symptoms and signs related to potential spinal cord impingement were seen with similar frequencies and of similar durations among cases and controls- meaning, focal deficits seen in both groups.
-noncontiguous co-infection: 53.7% of time (pneumonia, distant osteo, endocarditis… of those with a co-infection, 20% had more than one).
-blood cultures were positive 63.4% of the time, and >75% of the time it was staph Aureus.
-Majority of lesions were found in the L-spine at 56.2% – which means almost half are elsewhere!
-while “admits” for spinal abscess were up from 2.5 to 8 in 10,000 admissions from 2005 to 2015, I have to believe that number is somewhat inflated as admits like chest pain, pneumonia and renal colic probably decreased, while MRI became more readily available.
All in all, this paper is pretty much in line with others on this topic, and strengthens the signal a bit for certain key points: a good number of spinal abscesses are not in the L-spine; many patients are older than you think, and, among other things: its more than just IVDA.