first read back pain in the ED

see also:

• orthopaedics in the ED
• analgesics
• sensory & motor testing including dermatomes, myotomes, reflexes, coordination & balance
• groin pain
• buttock pain
• RANZCR Choosing Wisely for radiology investigations for low back pain
  • NB. these guidelines may apply to primary care cohorts but may NOT apply to ED cohorts where there are higher pre-test probabilities of serious pathology!
• Safer Care Vic: patient info sheet low back pain (pdf)

• trauma as for adolescent with back pain
• in intravenous drug users (IVDU) or injection drug use (IDU) patients, exclude epidural abscess, septic arthritis, osteomyelitis and vertebral osteomyelitis / discitis - do a CRP!
• sciatica/disc prolapse - usually 35-60 yr olds; pain on SLR; radiating pain +/- paraesthesiae down one leg.
  • need to exclude acute spinal cord compression and cauda equina syndrome (CES)
• mechanical musculo-skeletal lower back pain
• spinal stenosis - usually aged over 60yrs, pain worse on standing or walking
• degenerative facet joint syndrome - usually > 40yrs age; pain worse on rest; pain on SLR;
• acute pyelonephritis
• renal colic
• biliary colic
• sacro-iliitis:
  • ankylosing spondylitis (10% start before puberty, peak onset 15-25yr olds)
  • psoriasis (5% of pts with psoriasis)
  • Reiter's disease - males mainly; non-specific urethritis, polyarthritis (esp. sacro-iliac, lower limbs), conjunctivitis 
  • rheumatoid spondylitis (Bechterew's disease) - assoc. with chronic prostatitis, enteropathy, recurrent UTI or psoriasis, iritis.
  • see arthritis - clinical patterns for more details
• gynae. causes such as miscarriage, endometriosis
• neoplasia / cancer / tumours
  • multiple myeloma - esp. if age > 40yrs (only 3% occur under 40yrs) and any of: unusual osteoporosis (young or severe in elderly), normocytic anaemia, hypoalbuminaemia, hypercalcaemia, hyperproteinaemia or raised erythrocyte sedimentation rate (ESR)
  • metastatic deposits in spine - breast cancer, prostate cancer, etc
• rarely:
  • penetrating peptic ulcer
  • abdominal aortic aneurysm (AAA) (rare before 50yrs age)
    • rupture of a common iliac artery aneurysm may cause lumbosacral plexopathy and sciatica-like picture but a palpable iliac fossa mass and multiple root involvement help differentiate from disc prolapse sciatica
  • dissection thoracic aorta (usually have chest pain ⇒ back with PH Marfan's, Ehler's-Danlos, cong. heart disease or are pregnant
  • hypercalcaemia
  • lumbar triangle hernia
  • sciatic hernia through the greater or lesser sciatic foramen this can press on the sciatic nerve and cause sciatica
  • nutcracker syndrome of obstructed L renal vein, varicocele, left flank pain +/- haematuria
  • complication of a renal mass eg. haemorrhage/haematoma
  • retroperitoneal haemorrhage
  • sickle cell disease (SCD) - relatively rare in Australia and usually have PH sickle cell presentations as a child
  • spontaneous spinal epidural haematoma - usually associated with coagulopathy / warfarin Rx

• if IVDU, diabetic, immunocompromised or history of fever, exclude sepsis - do a FBE and CRP, and if raised consider emergent MRI
• avoid spine Xrays unless absolutely necessary as high radiation dose to gonads, and ensure not pregnant, and yield is not high unless either:
  • significant trauma
  • compressive trauma such as landing on feet from a height
  • severe hyperflexion such as a MVA lap belt injury or fall from height resulting in an unstable Chance fracture
  • risk of osteoporosis or pathological fracture
  • NB. CT scan is probably better risk benefit than plain Xrays if searching for a fracture
• if epigastric pain then consider:
  • PU - erect CXR for free gas
  • AAA in the older adult > 50yrs (see below)
• if severe colicky pain, rolling around in bed then peritonism and musculoskeletal pain is unlikely, think renal colic or perhaps biliary colic
• if midline tenderness with either fever or raised inflammatory markers, consider MRI scan for bacterial vertebral osteomyelitis / discitis (this can be life threatening)
• urinalysis:
  • if haematuria without leukocytes/nitrites, consider renal colic but absence of haematuria does not exclude it.
  • if large leukocytes &/or nitrites, consider acute pyelonephritis
• emergent MRI scan if
  • clinical features of cauda equina syndrome (CES) - this is particularly a risk in those with bilateral sciatica as this suggests a central disc prolapse
  • unexplained new neurology - not just a single lower limb radiculopathy (these could be managed with an OP MRI)
  • unexplained pain/neurology in context of coagulopathy/warfarin Rx - may be retroperitonal haemorrhage or a spinal epidural haematoma
  • unexplained raised CRP esp. if IVDU with back pain
• if sciatica, assess as per approach to sciatica
  • consider combinational Rx early - non-steroidal anti-inflammatory drugs (NSAIDs), paracetamol (+/- oxycodone if very severe and unlikely to go home although opiates should be avoided where possible in most patients with back pain)
  • document straight leg raise (SLR), neurology such as reflexes, lower limb neurology, bladder/bowel function and, if indicated, anal tone and sensation as well as post-void residual bladder scan (PVRs)
  • care coordinator to assess mobility, etc
  • if unlikely to be able to mobilise sufficiently to go home, then discuss with ED senior for possible admission under general medicine or into EOU if likely to be able to go home next day
  • CT scan or MRI scan for low back pain is very unlikely to be helpful IF there are no red flags such as possible cauda equina syndrome, tumour, fracture or possible spinal abscess/discitis/haematoma
    • MRI scan in the absence of red flags, whilst giving information regarding the status of discs, does not improve the back pain but does increase the risk of neurosurgical referral, and potential neurosurgery procedure despite the fact that long term outcomes of these procedures are similar to patients not having these procedures¹⁾
  • finally, consider assessing yellow flags for identifying psychosocial barriers to recovery:
    • ascertain the following potential barriers:
      • presence of beliefs that back pain is harmful or potentially severely disabling
      • fear-avoidance behaviour (avoiding a movement or activity due to misplaced anticipation of pain) and reduced activity levels
      • tendency to low mood and withdrawal from social interaction
      • an expectation that passive treatments rather than active participation will help.
    • ask about:
      • Have you had time off work in the past with back pain?
      • What do you understand is the cause of your back pain?
      • What are you expecting will help you?
      • How is your employer responding to your back pain? Your co-workers? Your family?
      • What are you doing to cope with back pain?
      • Do you think that you will return to work? When?
• if sacro-iliitis, check skin, nails for psoriasis, consider Xray for ankylosing spondylitis features, if male, ask about features of Reiter's
• if chest pain radiating to back - exclude dissection, PE, pneumothorax, etc.