Spinal infection and abscess: Clinical sciences

A spinal infection and abscess occurs from an inoculation of bacteria, fungus, or parasites in the vertebrae, intervertebral disc, or adjacent paraspinal tissues.

Spinal infections can progress into an epidural abscess, a walled-off collection of pus in the epidural space, which can compress and damage the spinal cord. If the infection is within the disc space, spondylodiscitis can occur, while infection of the vertebral bone itself is referred to as vertebral osteomyelitis.

Although these infections are rare, they're serious conditions that can lead to severe complications, such as paralysis or death, so timely diagnosis and appropriate treatments are very important.

Alright, when a patient presents with chief concern suggestive of spinal infection or abscess, your first step is to perform an ABCDE assessment to determine if the patient is unstable or stable. If the patient is unstable, stabilize the airway, breathing, and circulation. Next, obtain IV access and initiate IV fluids for resuscitation. Then, continuously monitor vital signs including pulse oximetry, blood pressure, and heart rate. Once acute management has been initiated, your next step is to obtain a focused history and physical exam, in addition to labs including a CBC, CRP, ESR, and two sets of blood cultures.

On history, your patient might report fevers, back pain, shooting nerve pain down the extremities, motor weakness, sensory changes, or bowel and bladder dysfunction. Additionally, history might reveal risk factors, such as diabetes, intravenous drug use, a chronic indwelling venous catheter, a concurrent infection elsewhere in the body such as tuberculosis, a recent spinal procedure, or immunocompromised state.

Physical exam will reveal hypotension and tachycardia, both concerning signs of sepsis. On palpation, you’ll also notice spinal tenderness; and sometimes a focal area of fluctuance; as well as neurological deficits like motor weakness, radiculopathy, or sometimes even paralysis.

On labs, you can expect to find leukocytosis with elevated CRP and ESR. With this presentation, you should suspect a spinal epidural infection or abscess with sepsis. To confirm your diagnosis, obtain an MRI of the spine with contrast. Keep in mind, the patient must be stabilized first prior to getting the MRI.

Now, once you obtain the MRI, you might see a fluid collection with rim enhancement and a hypointense center, dural enhancement, paraspinal and bone marrow edema, and longitudinal extension along the spinal column, which are all consistent with a spinal epidural infection or abscess, in this case with sepsis.

For treatment, start IV empiric antibiotics; and check the blood cultures to identify the causative pathogen and possibly tailor antibiotic coverage accordingly. Next, consult the surgical team right away for decompression and drainage. If drainage is performed, make sure to send a sample of the fluid for cultures and sensitivities.

Alright, let's go back and talk about stable patients. Your first step is to obtain a focused history and physical, in addition to labs including CBC, CRP, ESR, and two sets of blood cultures. Patients will again typically report a history of fevers, back pain, shooting nerve pain in the extremities, motor weakness, sensory changes, or bowel and bladder dysfunction.

Similarly, patients might have risk factors like diabetes, intravenous drug use, a chronic indwelling venous catheter, concurrent infection, recent spinal procedure or trauma, or an immunocompromised state. Physical exam often reveals spinal tenderness, and sometimes a focal area of fluctuance; as well as neurological deficits such as motor weakness, radiculopathy, bowel and bladder dysfunction, or even paralysis.

Labs can be normal or show leukocytosis with elevated CRP and ESR. With these findings, you should suspect a spinal infection or abscess. The modality of choice to further evaluate is an MRI of the spine with contrast. MRIs provide anatomic visualization of the parts of the spine affected by the infection that can help with your diagnosis.