What is the initial management approach for a patient with acute low back pain?

Initial Management of Acute Low Back Pain

For patients with acute low back pain without red flags, do not order imaging and focus on reassurance, activity modification, and first-line analgesics—imaging provides no clinical benefit in this setting and most patients improve within 4-6 weeks regardless of treatment. 1

Initial Assessment

History and Physical Examination Focus

Screen for red flags that require immediate intervention or imaging: 1, 2

• Cauda equina syndrome (saddle anesthesia, bowel/bladder dysfunction, bilateral leg weakness)
• Severe or progressive neurologic deficits
• Suspected infection (fever, IV drug use, immunosuppression)
• Suspected malignancy (history of cancer, unexplained weight loss, age >50 with new onset pain)
• Suspected fracture (significant trauma, osteoporosis, prolonged corticosteroid use)

Assess psychosocial risk factors that predict chronic disability: 1, 2

• Depression or anxiety
• Job dissatisfaction
• Expectation of poor recovery
• Catastrophizing behavior

Determine if radiculopathy is present: 1, 2

• Pain radiating below the knee
• Numbness or weakness in specific nerve root distribution
• Positive straight leg raise test

Imaging Decisions

Do not obtain imaging for uncomplicated acute low back pain (<4 weeks duration) without red flags. 1 Imaging abnormalities such as disc protrusions are present in 29-43% of asymptomatic individuals and do not correlate with symptoms. 1 Most disc herniations show reabsorption by 8 weeks. 1

Consider imaging only if: 1, 2

• Red flags are present on history/physical examination
• No improvement after 6 weeks of conservative management
• Patient is a potential candidate for surgery or epidural steroid injection

Preferred imaging modality when indicated: MRI is preferred over CT for evaluating radiculopathy or spinal stenosis. 1

Treatment Algorithm

Patient Education and Activity Modification

Provide reassurance about the favorable prognosis: 1, 2

• 90% of acute low back pain episodes resolve within 6 weeks regardless of treatment
• Advise patients to remain active and continue ordinary activities within pain limits
• Avoid bed rest—it leads to deconditioning and worse outcomes 1, 3

First-Line Pharmacologic Treatment

Start with acetaminophen (up to 3000mg/day) or NSAIDs (e.g., ibuprofen): 1, 2

• NSAIDs provide slightly better pain relief than acetaminophen but carry gastrointestinal, renal, and cardiovascular risks 1, 4
• Acetaminophen has a more favorable safety profile and is preferred in elderly patients 2, 4
• Both medications show moderate-quality evidence for small to moderate improvement in pain intensity 1

Do not use systemic corticosteroids—they show no benefit over placebo. 1, 2

Second-Line Pharmacologic Treatment (if first-line inadequate)

Consider skeletal muscle relaxants (e.g., cyclobenzaprine, tizanidine, metaxalone) for short-term use (2-7 days): 1, 2

• Moderate-quality evidence shows improved short-term pain relief
• High incidence of sedation limits use 4

Reserve opioids only for severe, disabling pain uncontrolled by acetaminophen and NSAIDs: 1, 2

• Use only after careful discussion of risks and realistic benefits
• Not first-line due to abuse potential 4

First-Line Nonpharmacologic Treatment

Recommend superficial heat application (heating pads, heated blankets): 1, 2

• Moderate-quality evidence for moderate benefits in acute low back pain
• Provides short-term relief

Consider spinal manipulation by appropriately trained providers: 1, 3

• Low-quality evidence for small to moderate short-term benefits
• More effective than sham therapy but not superior to conventional treatments 5

Consider massage or acupuncture: 1

• Low-quality evidence for modest effectiveness in acute low back pain

Reassessment and Escalation

Reassess at 4-6 weeks if no improvement: 1, 6

• Consider imaging at this point (not earlier)
• Consider referral for physical therapy with goal-directed manual therapy (not passive modalities like ultrasound or TENS) 3
• Evaluate for transition to subacute phase (4-12 weeks), which may require intensified treatment

Immediate referral to surgery if: 1, 6

• Cauda equina syndrome suspected
• Progressive neurologic deficits despite conservative management

Common Pitfalls to Avoid

Do not order routine imaging in the first 4-6 weeks—it does not improve outcomes and may lead to unnecessary interventions. 1 Even when imaging shows disc herniation, most resolve spontaneously. 1

Do not prescribe prolonged bed rest—it worsens outcomes and increases disability. 1, 3

Do not use systemic corticosteroids—they lack efficacy for nonspecific low back pain. 1, 2

Do not overlook psychosocial risk factors—they are strong predictors of progression to chronic disabling pain and should be addressed early. 1, 2