Low Back Pain

1. Low Back Pain Mette Adkisson, M.D.

2. Low Back Pain • Up to 90% of adults have back pain in their lifetime • 15 million patients per year in the US • 2% of all ED visits • Total cost per year: • More than $100 billion • 75% of that cost is spent on fewer than 5% of patients with LBP

3. Low Back Pain • 90-95% of LBP visits are non-emergent • So why so many visits? • 72% of those who seek treatment give up exercising and sports-related activities • 60% say they are unable to perform some ADLs • 46% say they gave up sex because of back pain

4. Risk factors to develop LBP • Smoking • Obesity • Older age • Female gender • Strenuous work • Sedentary work • Low education level • Worker’s comp insurance • Job dissatisfaction • Anxiety/depression

5. Spondylosis: arthritis Spondylolisthesis: anterior displacement of a vertebra on the one beneath it. Grade 1-2: up to 50% slip. Medical mgmt. Grade 3-4: 51 – 100% slip. Poss surgery. Terminology

6. Terminology • Spondylolysis: fracture or defect in the pars interaticularis where the verterbral body and posterior elements join

7. Terminology • Spinal Stenosis: narrowing of the central spinal canal by bone or soft tissue • Radiculopathy: Impairment of a nerve root • Sciatica: Pain, n/t, in the distribution of the sciatic nerve • Cauda equina syndrome: Narrowing of the spinal canal that compresses the nerve roots below the level of the spinal cord

8. Terminology • Piriformis syndrome: Piriformis muscle compresses or irritates the sciatic nerve. Debate as to whether this is a true condition.

9. Differential Diagnosis • Mechanical: 97% • Lumbar strain 70% • Degenerative disk • Herniated disk • Sciatica 1.5% of back pain, • <1 % of these develop cauda equina • Sciatica is 95% sensitive for lumbar disk herniation • Spinal stenosis • Compression Fracture • Spondy’s

10. Differential Diagnosis • Visceral: 2% • Aortic aneurysm • Pelvic disease (PID, prostatitis) • Renal disease (pyelo, kidney stones) • Non-mechanical: ~1% • Neoplasia • Infection: osteo, abscess, shingles

11. Evaluation: History • “Red flags” for serious causes of pain: • Recent significant trauma or trauma with age > 50 • Unexplained weight loss • Fever • Immunosuppression • History of cancer

12. Evaluation: History, Red Flags • IVDU • Age > 70 • Osteoporosis • Focal neurologic deficit or disabling symptoms • Duration greater than 6 weeks

13. Evaluation: History • Pain not relieved by lying down concerning for cancer/infection • Pain radiating below the knee is more likely true radiculopathy rather than proximal leg pain • Nl pulses but transient tingling in the legs and ambulation-induced pain localized to the calf and lower extremity resolving with rest are indicative of neurogenic claudication/spinal stenosis • Assess abdominal aorta in older patients

14. Evaluation: Clinical Exam • Is there evidence of systemic or neurologic compromise? • Inspection • Range of motion • Straight leg testing, confirms radiculopathy • Palpation of the spine • Neurologic exam

15. Evaluation: Neurologic Exam • Spinal cord compression • Motor deficits most common • Found in 85% • Sensory deficits slightly less common • Bowel/bladder dysfunction late finding

16. Evaluation: Neurologic Exam • Any pt with report of saddle anesthesia, b/b dysfcn, neuro deficit, or severe pain MUST have a documented rectal exam • Suspected cord compression should have post-void residual (greater than 100-200mL = positive) • Post-void residual: acute urinary retention 90% sensitive and 95% specific for cauda equina

17. Evaluation: Neurologic Exam • 98% of clinically important disc herniations occur at L4-5 and L5-S1 • L5: ankle and great toe dorsiflexion; sensory to medial foot and web space bw 1st and 2nd toe • S1: ankle reflex, sensation post calf and lat foot • Note: ankle reflex increasingly absent with age, but only unilateral in 10%

18. Evaluation: Imaging • Imaging is infrequently needed • Remember: gonadal radiation from a two view radiograph of the lumbar spine is equivalent to the radiation exposure from a CXR taken daily for more than 1 year! • Imaging is not necessary during the 1st 4-6 weeks of back pain as long as the patient does not have…

19. Evaluation: Imaging • Recent significant trauma or trauma with age > 50 • Unexplained weight loss • Fever • Immunosuppression • History of cancer • IVDU • Age > 70 • Osteoporosis • Focal neurologic deficit or disabling symptoms

20. Evaluation: Imaging • Lumbar X-rays, CT, and MRI are often abnormal in asymptomatic patients • 23% of asymptomatic adults have DDD on plain films of the L-spine • 22-40% of asymptomatic adults have disc herniation on MRI • 21% of adults over 60 have spinal stenosis on MRI

21. Evaluation: Imaging • Plain films: • Mainly used to r/o fracture • May show evidence of infection, malignancy, spondy’s, DDD, prior surgery • Sensitivity of plain radiographs for spinal mets is 60% • 17% of patients with spinal cord compression have nl XR • Osteomyelitis and spinal epidural abscess: 82% sensitive

22. Evaluation: Imaging • CT: • Mainly helpful in demonstrating bony abnormalities not seen or unclear on plain films • MRI: • Best test for patients who require advanced imaging unless bony abnormality suspected • This is the only test that can exclude spinal cord compression or abscess

23. Evaluation: Lab • WBC > 12 present in only 40-60% of patients with spinal infection • ESR/CRP elevated in 90% of patient’s with spinal infection • That means up to 10% can have normal values! Don’t rely only on ESR/CRP.

24. Treatment of non-emergent LBP • NSAIDs: Global symptomatic improvement after one week was greater for patients treated with NSAIDs than placebo. • Likely no more effective than APAP. • Non-bzd muscle relaxants are more effective than placebo.

25. Treatment of non-emergent LBP • Combination therapy of NSAIDs and and muscle relaxant provide most effective symptom relief • Limit muscle relaxants to 1-3 weeks of therapy • Use of opiates is a matter of clinical judgement • No benefit to using steroids

26. Treatment of non-emergent LBP • Multiple trials show NO role for bed rest, even in sciatica. • Rapid return to normal activity and ADLs is best activity recommendation. • Exercise can prevent 1st episode of back pain and prevent recurrences • Corsets and braces do not have therapeutic value • Cold does not appear to help pain, but heat wraps may reduce pain

27. Treatment of non-emergent LBP • Early referral to PT does not change outcomes • Patients who are treated with massage and yoga have the same symptom response as medications but higher patient satisfaction rates • Mattress recommendations: whatever

28. Special Consideration: Spinal Epidural Abscess • Below the foramen magnum an epidural space exists posterior to the spinal cord • Extends the length of the canal • Small in the cervical region, large in the sacral region • Anterior to cord only a potential space until L1 • Therefore majority of SEAs are posterior, if anterior usually located below L1 • Abscesses commonly extend multiple levels

29. SEA: Epidemiology • Occurs in 2 – 25 out of every 100,000 admits • Median age of onset 50 y.o. • Prevalence greatest between age 50 and 70 • Risk factors: • Epidural catheter placement (0.5-3%) • Immunosuppresion (DM, HIV, EtOHism) • Trauma • Tattooing • Acupuncture • IVDU

30. SEA • 1/3 have no identifiable source of infection • Most common sites of origin: • Infections of skin and soft tissue • Complications of spinal surgery or other invasive procedures • In epidural abscesses associated with epidural catheters, link between infecting organism and nasal swabs taken from the physician placing the catheter! • 1/3 from hematogenous infection. Think IVDU!!

31. Microbiology • Staph aureus: 63% • 40% of these are MRSA • Gram-neg bacilli: 16% • Streptococci: 9% • Coag-neg staph: 3% • Anaerobes: 2% • Other (fungi, parasites): 1% • Unknown: 6%

32. Clinical Manifestions • Classic triad: • Fever • Back pain • Neruologic deficits • Fever is the most likely of these to be absent • 63 patients with SEA: • Median number of ED visits before admit • 2 (with a range of 1 – 8)

33. Clinical Manifestation • Symptoms progress in typical sequence • Back pain, focal and severe • Root pain, described as “shooting” or “electric shocks” • Motor weakness, sensory changes, b/b dysfunction • Paralysis

34. Diagnosis • ESR usually elevated • Hct normal • WBC elevated or normal • MRI is the preferred test for diagnosis • If pt unable to MRI then CT with gad • If you suspect it, you MUST image to find it!

35. Management • Reduce size and eliminate inflammatory mass • Eradicate causative organism • Antibiotics • Vancomycin, metronidazole, AND ceftriaxone • Surgical decompression within 24 hours

36. Prognosis • 5% of SEA patients die • Irreversible paraplegia in 4-22% • Neurologic recovery unlikely if paralysis is present for more than 24 hours prior to surgery

37. The End

38. References Marx, J. (editor) “Rosen’s Emergency Medicine, Concepts and Clinical Practice”. 5th Ed. 2002. Mattu, A. and Goyal, D. (editors) “Emergency Medicine: Avoiding the Pitfalls and Improving the Outcomes”. 2007. Up to Date (ww.uptodate.com), Articles: “Approach to the diagnosis and evaluation of low back pain in adults” “Diagnostic testing for low back pain” “Treatment of acute low back pain” “Epidural abscess”