Case Report
A 43-year-old African American male presented to the emergency
department via ambulance with altered mental status, visual
hallucinations, and excruciating back pain as reported by an
accompanying caretaker. On arrival, the patient was afebrile (Temp: 97.6
ºF), mildly tachycardic (HR: 98 BPM), and hypotensive (BP: 98/63 mmHg).
Further examination revealed an ill-appearing, obese male in no acute
distress. The patient was disoriented to place and time and was unable
to follow simple commands. A detailed neurological examination could not
be performed due to a lack of cooperation. Vision was grossly intact and
cardiovascular examination revealed a normal S1 and S2, irregular rate
and rhythm, but no murmurs, rubs or gallops. The patient had a history
of poorly controlled insulin-dependent diabetes mellitus, end-stage
renal disease on maintenance hemodialysis via right internal jugular
vein (IJV) vascular catheter, persistent atrial fibrillation
anticoagulated with apixaban (10 mg/d), and bilateral below-the-knee
amputation secondary to diabetic complications with chronic
osteomyelitis from MRSA. The patient had a history of medical
noncompliance and reported discontinuous medical care managed at
multiple distant care facilities.
A non-contrast computed tomography (CT) scan of the neuraxis revealed a
destructive process in the thoracic spine at T7-T8 suspicious for
discitis and osteomyelitis (Figure 1A) with unremarkable lumbar findings
(Figure 1B). CT imaging of the head was negative for neurologic
abnormalities. Subsequent imaging studies were limited by the severity
of the patient’s pain and positioning restrictions. A complete blood
count was within normal limits besides mild anemia (Hb: 10.1 gm/dL, Ref:
13.0-18.0 gm/dL). Complete metabolic panel revealed elevated blood urea
nitrogen (41 mg/dL, Ref: 10-20 mg/dL), creatinine (3.99 mg/dL, Ref: 0.6
to 1.2 mg/dL), and lactic acid (3.0 mmol/L, Ref: 0.5-2.2 mmol/L). The
patient did not meet sepsis criteria on arrival and was admitted for
bacteremia in light of purported vertebral osteomyelitis or renal
dialysis spondyloarthropathy. At the time of admission, orders were
written for post-dialysis IV vancomycin (2g every eight hours) and
cefepime (1000mg daily). The patient was unable to receive dialysis
until post-admission day three, at which time he was safely administered
the antibiotic regimen.
The patient’s encephalopathy, back pain, and bacteremia was monitored
and managed through day three of admission without significant change.
Magnetic resonance imaging (MRI) of the thoracic spine confirmed
osteomyelitis at T7-T8 and a similar yet earlier infectious process
occurring at T10-T11 (Figure 2). Blood culture results at day three
revealed methicillin-resistant S. aureus (MRSA). A
CT-guided biopsy of the spinal abscess was scheduled but was later
cancelled by the patient and caretaker. The patient was managed on an
in-patient basis for a total of sixteen days with serial blood cultures.
Repeat blood cultures at the end of week one remained positive for MRSA.
The patient’s right IJV vascular catheter was removed and tested
positive for MRSA. The patient’s vascular catheter was replaced in the
left IJV and subsequently tested positive for MRSA. Vascular access was
removed briefly before being replaced in the right IJV. Following the
third MRSA positive culture and the lack of response to vancomycin,
antibiotic therapy was superseded by intravenous daptomycin (800 mg
post-dialysis triweekly) and rifampin (300 mg twice daily).
Blood cultures remained positive for MRSA at the beginning of week two.
Concerns surrounding the persistent bacteremia prompted a transthoracic
echocardiogram (TTE), which revealed the presence of a mobile vegetation
on an embryological remnant of the inferior vena cava, a eustachian
valve remnant, within the inferior aspect of the right atrium (Figure
3). In-patient intravenous daptomycin was continued through
post-admission day 13, when the patient’s cognitive symptoms resolved.
The patient was discharged at post-admission day 16 with arrangements to
return for scheduled intravenous daptomycin infusions for an additional
six weeks. Following antibiotic therapy, the patient has not returned
for treatment related to this condition.