Synopsis
Recognise spinal epidural infection before the classic triad is complete, obtain MRI and microbiology in the correct sequence, and distinguish stable diagnostic sampling from neurological or septic rescue.
- Think of SEA in severe localised spinal pain with infection risk, raised ESR/CRP, bacteraemia or neurological change; do not wait for the full pain-fever-deficit triad.
- MRI of the relevant spine without and with contrast is usually appropriate and defines epidural, disc, vertebral and paraspinal involvement; image a wider extent when symptoms or findings are multifocal.
- Before antibiotics, obtain two sets of aerobic and anaerobic blood cultures and baseline ESR/CRP when this does not delay emergency treatment.
Key red flags
New severe focal back or neck pain plus weakness, sensory change, gait deterioration or bladder/bowel dysfunction.
Back pain with fever, raised inflammatory markers, bloodstream infection, infective endocarditis or recent Staphylococcus aureus bacteraemia.
Diabetes, injection drug use, immune compromise, dialysis, an indwelling vascular catheter or another source of bacteraemia increases risk but absence of a risk factor does not exclude disease.
Recent spinal surgery, injection or instrumentation suggests postoperative or procedure-related infection; device and pathogen assumptions differ from native community-acquired disease.
The classic triad of pain, fever and neurological deficit is often absent early. Afebrile presentation does not safely exclude infection.
Rapid progression, sepsis, haemodynamic instability, cervical or thoracic cord signs or extensive disease requires immediate source-control and airway/critical-care planning.
New severe focal pain, night pain, percussion tenderness or radicular pain may be the only early clue. Fever and deficit are neither required nor reliably simultaneous.
Record segmental power, tone, reflexes, sensory level, saddle sensation, gait and sphincter function. A new or progressive deficit requires immediate surgical and antimicrobial action.
Recent spinal surgery, epidural injection or implanted material changes organisms, anatomy and need for source control. Escalate to the operating or specialist spinal service early.
Reasoning priorities
Define the epidural collection, neural compression and associated disc, vertebral or paraspinal infection.
Urgency follows neurological and septic state. Image the symptomatic region promptly and extend coverage when multifocal symptoms, bacteraemia or discontinuous infection is plausible. Gadolinium best shows epidural extension in NVO.
Worked reasoning
A febrile patient with severe thoracic pain develops rapidly progressive leg weakness and hypotension.
- Recognise possible SEA with neural compression and sepsis; activate spinal surgery, infection/microbiology, anaesthesia and critical care immediately.
- Obtain two blood-culture sets and baseline tests if they can be taken without delay, then start empiric intravenous antimicrobials using the current local severe-spinal-infection pathway.
- Arrange urgent contrast-enhanced MRI while resuscitating. Do not postpone antimicrobials or surgical assessment for a planned percutaneous biopsy.
- Proceed to urgent decompression/drainage and operative sampling when indicated by the spinal team; address stability and any additional infective source.
- Narrow treatment to culture and susceptibility results and set duration through infection specialists according to compartment, organism, source control, bone/disc involvement, host and response.
A stable adult has persistent focal pain, raised CRP and MRI showing disc-endplate infection with a small epidural component but no neurological deficit.