CanadiEM Frontline Primer

CanadiEM Frontline Primer – Back Pain

In Medical Concepts by Afsheen MeharLeave a Comment

Can’t Miss Diagnoses

  • Unstable vertebral fracture
  • Cord compression causing Cauda Equina Syndrome
    • CES: Epidural abscess, hematoma
  • Spinal Abscesses
  • Discitis
Killer Mimics:
  • Vascular
    • Aortic dissection, Ruptured aortic aneurysm
  • Renal
    • Pyelonephritis, renal colic
  • Pneumonia
  • Pelvic conditions
    • Prostatitis, PID

Red Flags of Back Pain

Important to assess in DM, History of malignancy, anti-coagulation, osteoporosis, IVDU, steroid and immunocompromised states, and associated alarm symptoms like fever, syncope (aortic dissection). Here is a nifty mnemonic that may be useful:

B – Bowel (incontinence) or Bladder (retention) dysfunction
A – Anesthesia of Saddle region (saddle anesthesia)
C – Cancer History or Constitutional Symptoms (?abscess)
K – Killer Pain / Constant Pain

P – Parasthesias of lower limb
A – Age greater than 50
I – IV drug use, recent infection, immunocompromised
N – Neuromotor deficits

Points to focus upon

Assess ABC, O2 need, complete neurologic exam including gait-walk and midline and paraspinal tenderness as well as reproducibility.
All back pain examinations with neurological deficits should have routine documented assessment until care is transferred to the spine team. Worsening deficits warrant a rapid assessment by the spine team.

Cauda Equina Syndrome (CES) – Screen for and document the presence or absence of the following:

  • Urinary Retention (but may have overflow incontinence)
  • Fecal incontinence
  • Saddle anesthesia

You can have a PARTIAL CES.

Screen for Red Flags (See above)

Document the presence or absence of red flags

Px: (read more here)
  • Post void residual (PVR) volume to assess urinary retention.
    • Less than 50mL PVR is adequate bladder emptying. Over 200mL PVR indicates inadequate emptying.
  • DO A DIGITAL RECTAL EXAM (Rectal tone).
  • Repeating serial examinations is prudent, mainly to see if there has been a change in symptoms.
  • Document pattern of symptoms (ideally with ASIA), especially where symptoms are worse (distal vs proximal, motor vs sensation).

Epidural abscess at any setting can cause symptoms of CES; MRI the entire spine if this is a consideration (fever or sepsis with unrelenting back pain).


An X-ray of the area of the spine for most individuals over 50 years of age is reasonable.
Make sure you get two views on L-spine X-ray (AP & Lateral).

Tips on Tests

CXR – looking for alternative diagnoses (Pneumothorax, pneumonia) or incidental findings (ground-glass opacities, suggestive of COVID-19)



Remember, Mechanical LBP is a diagnosis of exclusion.
NSAIDs where warranted, and Acetaminophen.
Breakthrough opioids when necessary or if other medications are contraindicated (e.g. if patient is on DOAC/Warfarin and cannot have NSAIDs
Patient education is imperative for adherence. The CORE back pain tool and exercises they can tolerate (see below).


Assess for sepsis, consider anti-emetic, analgesic and IVF early on.


Consider Antibiotics early in case of Fever and LBP, and/or story consistent with spinal intervention, IVDU or immunosuppression and concern for Epidural abscess (MRI).

Patient Education Materials

Recommended reading, videos, and podcasts

The following is part of the CanadiEM Frontline Primer. An introduction to the primer can be found here. To return to the Primer content overview click here.

This post was edited by Dr. Brent Thoma MD FRCPC. This post was copyedited and uploaded by Evan Formosa.

Afsheen Mehar

Dr. Afsheen Mehar is a resident physician at the University of Toronto in the RCPSC Emergency Medicine Training Program. Her greatest passions are medical education, POCUS and austere medicine. She holds an RDMS certification in ultrasound.
- 5 months ago

Colm McCarthy

Colm completed his residency at McMaster University in orthopaedic surgery along with a 5 month fellowship in orthopaedic trauma surgery. He will be having a second fellowship in hip and knee reconstruction at the Brigham and Women’s Hospital. He enjoys collaborative work, medical education, and physical advocacy.

Teresa Chan

Senior Editor at CanadiEM
Emergency Physician. Medical Educator. #FOAMed Supporter, Producer and Researcher. Chief Strategy Officer of CanadiEM. Associate Professor, Division of Emergency Medicine, Department of Medicine, McMaster University.
- 3 hours ago