see also:

• analgesics, drug dependent patients
• orthopaedics in the ED
• abdominal pain in the ED
• the lumbosacral spine Xray
• 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!
• Back pain general patient information
• Back pain and imaging - general patient information
• Safer Care Vic: patient info sheet low back pain (pdf)

• back pain can be a very deceptive presentation, all too easily put down to muscle strain or disc prolapse while missing potentially time critical diagnoses.
• watch for red flags in the presentation and specifically search for and exclude the main differentials.
• patients with chronic back pain can be difficult to manage in the ED and requires a degree of experience to avoid traps
• avoid opiates and tramadol in back pain as evidence suggests they are of little benefit over non-steroidal anti-inflammatory drugs (NSAIDs) and do more harm, especially for chronic pain, instead consider a stat dose of corticosteroids such as 75mg prednisolone if acute disabling disc prolapse pain
• most patients DO NOT warrant a lumbo-sacral Xray as these are high radiation procedures and usually have a low pick up rate
  • consider CT scan if significant trauma, or MRI if acute low back pain and specific indications - see BELOW!
• one of the first steps in assessing these patients in ED is to determine the pain pattern to better direct you down the correct path:
  • is it thoracic back pain - see acute thoracic back pain in the adult
  • is it upper abdominal pain radiating to the back - think pancreatitis, penetrating DU, abdominal aortic aneurysm (AAA), or biliary colic (see RUQ abdo pain)
  • is it lower abdominal pain radiating to the back - think gynaecologic causes such as dysmenorrhoea, miscarriage, endometriosis, imperforate hymen in puberty
  • is it flank pain radiating to the groin - think renal colic or perhaps acute pyelonephritis, or less likely, abdominal aortic aneurysm (AAA), or an acute scrotal pathology such as torsion of testes (CHECK them!)
  • is it sudden onset after lifting or perhaps tripping with pain radiating down a leg +/- paraesthesiae - think sciatica
  • check for herpes zoster (shingles)
  • is there a possibility of metastatic neoplasia / cancer / tumours (eg. breast cancer) or associated urinary or bowel continence issues - search for possible acute spinal cord compression or cauda equina syndrome (CES)
  • is it a more chronic pain due to sacro-iliitis or a spine aetiology - see arthritis - clinical patterns

• osteomyelitis, vertebral osteomyelitis / discitis, paraspinal/spinal cord abscesses
  • fever
  • risk factors for spinal bacterial infection:
    • underlying disease, immunosuppression, penetrating wound, intravenous drug use, recent staph infection, recent acupuncture or dry needling
  • sacro-iliac septic arthritis
    • unilateral tenderness over PSIS, usually with fever
    • this is a rare condition and is usually staphylococcal but can be salmonella
    • may occur after normal vaginal delivery (possible role of epidural or spinal anaesthesia but this is unclear as it is usually haematogenous spread or perhaps following local steroid injection)
    • risk factors are as for spinal sepsis (see above)
    • MRI is the best Ix and may show fluid over lumbosacral plexus and psoas muscles with associated myositis
    • Rx is IV antibiotics with staph coverage; usually not able to be drained, and thus generally admitted under ID.
• spinal tuberculosis (TB) (Pott's disease)
  • no fever, no redness, chronic course, usually thoracic or lumbar spine which is tender, there may be kyphosis from destruction of spine
  • less than 40% have extra-skeletal TB
  • neurology may occur early
  • large, cold abscesses of paraspinal tissues or psoas muscle may protrude under the inguinal ligament and may erode into the perineum or gluteal area
  • upper Cx spine cases can be rapidly progressive and cause early neurology and retropharyngeal abscesses
  • plain XR if suspicious
  • spinal tuberculosis should always be suspected when radiographs demonstrate a destructive spinal process.
• fracture risk?
  • major trauma
  • minor trauma, if >50 years old, with a history of osteoporosis, and/or taking corticosteroids
  • mechanism of injury for possible unstable Chance fracture - hyperflexion such as MVA with lap belt or fall from a height
• malignancy risk?
  • PH malignancy
  • >50 years old
  • Unexplained weight loss (e.g. >4.5kg in <6 months)
  • Pain at multiple sites
  • Pain at rest
• abdominal aortic aneurysm (AAA)
  • Sudden onset
  • Associated collapse/hypotension
  • Pain not aggravated by spinal movement
  • Abdominal pain radiating to back
  • low index of suspicion - consider ED bedside USS or CT scan ASAP
• cauda equina syndrome / acute spinal cord compression
  • saddle anaesthesia
  • urinary and/or faecal incontinence or retention, of recent onset
  • in addition, consider urgent MRI for potential cause equina onset in those who have no neurology but severe and unrelenting low back pain of acute onset
  • this is an indication for MRI scan preferably on day of onset as delay in Rx may increase risk of permanent urinary disturbances
• risk of retroperitoneal haemorrhage:
  • anticoagulants or bleeding diasthesis
  • renal or adrenal tumours
  • connective tissue disease or vasculitis

• high impact trauma with possible unstable Chance fracture or other spinal fracture such as
  • MVA - especially if wearing lap belt at speed
  • acute axial loading - fall from height onto feet
  • acute hyperflexion
• suspected retroperitoneal haemorrhage
• suspected renal trauma (usually a contrast CT is indicated)
• suspected AAA (preferably contrast CT aortogram)
• suspected renal colic and either single kidney, suspected sepsis or severe pain not resolving (CT KUB)

• evidence of cauda equina syndrome such as either:
  • new urinary symptoms or urinary retention
  • faecal incontinence
  • saddle anaesthesia
• suspected or possible spinal infection
  • see above
• severe neurologic deficits
• suspected neoplastic aetiology
  • history of cancer with new onset pain

• lower probability of neoplastic aetiology
  • unexplained LOW, age > 50yrs, ESR > 100, or h'crit < 30%
• possible ankylosing spondylitis
  • morning stiffness improves with exercise
  • alternating buttock pain
  • awakening in 2nd part of night due to back pain
  • age 20-40yrs
• possible spinal stenosis and potential candidates for surgery
  • older age
  • pseudoclaudication
  • radiating leg pain
• radiculopathy and potential candidates for surgery
  • sciatica with pain in L4, L5 or S1 distribution
  • positive SLR test
• suspected vertebral fracture
  • consider plain XRay first
  • 2 or more risk factors: corticosteroids, age > 70, female, significant trauma

• suspected vertebral fracture
  • 2 or more risk factors: corticosteroids, age > 70, female, significant trauma
  • but if Xray negative, still consider an MRI

• the adolescent with back pain
• the adult with back pain
• the elderly with back pain
• flank pain - is it renal colic?
• sciatica - usually this is in association with a painful SLR
• high lumbar disc prolapse - the “sciatica” you get with potentially normal SLR!
• sacro-iliitis
• mechanical musculo-skeletal lower back pain
• arthritis - clinical patterns
• spondylolisthesis
• spinal stenosis
• cauda equina syndrome (CES)