Can’t Miss Diagnoses
- Unstable vertebral fracture
- Cord compression causing Cauda Equina Syndrome
- CES: Epidural abscess, hematoma
- Spinal Abscesses
- Aortic dissection, Ruptured aortic aneurysm
- Pyelonephritis, renal colic
- 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)
IF MECHANICAL BACK PAIN IS YOUR MAIN SUSPECTED DIAGNOSIS:
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).
IF RENAL COLIC IS YOUR MAIN SUSPECTED DIAGNOSIS:
Assess for sepsis, consider anti-emetic, analgesic and IVF early on.
IF SPINAL ABSCESS IS YOUR MAIN SUSPECTED DIAGNOSIS:
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
- Core Back Pain Tool
- Dr. Mike Evan’s Back Pain Video
- Saskatchewan Exercise Guides for Patient Education
- Pattern 1 – Pain is worst in the back, buttocks, upper thigh, or groin (may radiate to the legs)
- Pattern 2 – Pain is worst in the lower back (may spread to buttocks or legs)
- Pattern 3 – Pain is mainly in the legs but back pain may be present
- Pattern 4 – Pain is worst in legs and can be described as heaviness or aching
Recommended reading, videos, and podcasts
- Deeper Dive CanadiEM Post on Physical Exam in Back Pain
- Exam Series: Guide to the Back Exam
- ASIA ISCOS Tool for Classifying Spinal Cord Injury
- Post-Void Residual Volume
- Tiny Tips: Back Pain Differential Mnemonic
- Tiny Tip: CES for Cauda Equina Syndrome
- CRACKCast E035 – Back Pain
- Low Back Pain Emergencies – Emergency Medicine Cases
- Lumbar Disc Herniation – Orthobullets
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.