Rational Approach to Treating Low Back Pain

Transcription

1 Rational Approach to Treating Low Back Pain Susie Jang, MD Department of Anesthesia, Critical Care & Pain Medicine Beth Israel Deaconess Medical Center Instructor, Harvard Medical School

2 Learning Objectives Overview, impact of low back pain Identification of patients at risk of developing chronic LBP Initial encounter and development of a structured plan for work-up Incorporate a rational and evidence-based approach of available treatments Obtaining timely referral to pain management and surgical specialists

3 OVERVIEW AND EPIDEMIOLOGY

4 Everyone Gets Back Pain Back pain and related symptoms 2 nd most frequent complaints for PCP visits 5 th most common reason for all physician visits Second only to common cold as cause of lost work time In the U.S., lifetime prevalence approximately 80%, one-year prevalence 15% - 20% 90% - non emergent causes 85% - no exact diagnosis Highest prevalence between 45 to 64 age group Most common cause of disability in < 45 years old

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6 Back Pain is Expensive Total cost of back pain in US $253 billion per year (2011) $150.4 billion - hospital treatment cost (2011) 291 million lost work days per year (2012) Ranked highest for cause of disability worldwide (WHO, Global Burden of Disease Survey 2010) Spinal fusion - 6th most common OR procedure, most expensive in 2011 (Agency for Healthcare Research and Quality 2014) Medical Expenditures Panel Survey (MEPS), Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services, National Health Interview Survey (NHIS)_Adult sample,

7 Back Pain Context 307% 423% 629% 220% Deyo RA, et al. Overtreating Chronic Back Pain: Time to Back Off? Journal of the American Board of Family Medicine. 2009;22(1):62-68.

8 Deyo RA, et al. Overtreating Chronic Back Pain: Time to Back Off? Journal of the American Board of Family Medicine. 2009;22(1):62-68.

9 Most Disability Improves with Time 85% return to work after short episodes of acute LBP

10 But Some People Never Get Better Recovery after 12 weeks slow, uncertain Disabled for 6 month: < 50% return to work Disabled for 1 year: 25% After 2 years absence from work: approaches 0%

11 Chronicity of Low Back Pain Acute: 2-4 weeks Subacute: up to 12 weeks Chronic: > 12 weeks 75-90% of patients with acute LBP in primary care improve within 1 month Exact etiology of acute LBP is identifiable in only 15% of patients

12 Predictors of Pain Chronicity Protective: College education Risk: Unemployed Radiating/wide spread pain, radicular pain Inability to walk for an hour Insomnia, sleep disturbance Catastrophizing Kinesiophobia Tobacco use

13 INITIAL EVALUATION

14 Initial Encounter Thorough history of pain complaint Onset Location, radiation Aggravating factors Alleviating factors Other health or pain problems Cancer history Psych history

15 DIFFERENTIAL DIAGNOSIS & WORKUP

16 Etiologies of Low Back Pain Musculoligamentous injuries Intervertebral disks and facet joints degeneration Herniation of the nucleus pulposus of an intervertebral disk Spinal stenosis Anatomic anomalies of the spine: scoliosis, spondylolisthesis Underlying systemic diseases Primary or metastatic cancer Spinal infections Ankylosing spondylitis Visceral diseases unrelated to the spine Pelvic organs Kidneys Gastrointestinal tract/pancreas Aorta

17 Prevalence of Multiple Etiologies Musculoligamentous injury or degenerative changes - 85% Lumbar spinal stenosis % (incr with age, imaging) Compression fractures - 4% Spondylolisthesis - 3% Spinal malignant neoplasms (primary or metastatic) - 0.7% Ankylosing spondylitis - 0.3% Spinal infections %

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20 Rule Out Cancer Primary or metastatic 80% of patients with cancer as cause > 50 years old Previous history of cancer = cause of pain until proven otherwise Common metastatic: Breast, lung, prostate, lymphoma, renal cell, GI, melanoma Symptomatic due to bone pain, pathologic compression fractures, extension into spinal canal

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22 Rule out Cancer - continued Symptoms: Unexplained weight loss Pain lasting >1 month Not responsive to conservative therapy Not relieved by rest Physical exam: Spinal tenderness: specific, varied sensitivity Neuromuscular: weakness, atrophy, reflex changes, sensory deficits high specificity Muscle spasm, radiculopathy, Babinski s sign, urinary retention poor sensitivity

23 Spinal Infections While rarely seen, very important to rule out: Blood borne from other sites: UTI, IVDA, skin infections Sx: Fever, diaphoresis, localized spine tenderness

24 . Cauda Equina Syndrome

25 Cauda Equina Syndrome RED FLAGS Severe low back pain (LBP) Radicular pain: often bilateral but sometimes absent, especially at L5/S1 with an inferior sequestration Saddle and/or genital sensory disturbance Bladder, bowel and sexual dysfunction Needs urgent surgical evaluation Eur Spine J May; 20(5):

26 Cauda Equina Syndrome Incomplete: neurogenic urinary difficulties altered urinary sensation loss of desire to void poor urinary stream need to strain in order to micturate saddle and genital sensory deficit often unilateral or partial; trigone sensation should be present. Complete: painless urinary retention and overflow incontinence bladder no longer under executive control. usually extensive or complete saddle and genital sensory deficit with deficient trigone sensation. Eur Spine J May; 20(5):

27 Compression Fractures Although not "systemic" diseases, often with generalized osteoporosis Most patients DO NOT have a history of identifiable trauma Back pain with long-term corticosteroid therapy should prompt consideration of compression fracture African-American and Mexican-American women have only one fourth as many compression fractures as white women Age > 70 years is relatively specific

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29 TLICS: Thoracolumbar Injury Classification and Severity Score Morphology: immediate stability, XR/CT compression fracture - 1 point burst fracture - 2 points translational rotational injury - 3 points distraction injury - 4 points Posterior ligamentous complex: long term stability, MRI intact - 0 points suspected injury or indeterminate - 2 points injured - 3 points Neurologic involvement: Physical exam intact - 0 points nerve root - 2 points cord/conus medullaris (complete) - 2 points cord/conus medullaris (incomplete) - 3 points cauda equina - 3 points

30 TLICS cont. Based on total points, help determine plan based on co-morbidities and injury 0-3: usually treated non-operatively 4: surgeon's choice, +/- OR >4: usually treated operatively J Orthop Sci Nov; 10(6):

31 Is There Evidence of Neurologic Compromise? Radicular Pain?

32 Radicular Pain Overview Pathology affecting spinal cord, cauda equina, nerve roots Most common cause: herniated intervertebral disk Nerve root entrapment in the root canals due to bony and ligamentous hypertrophy spinal stenosis spinal or paraspinal infections cancer Present as motor, reflex, or sensory dysfunction in the lower extremities, bowel or bladder dysfunction If only low back pain, no radicular pain or neurologic symptoms, prevalence of neurological impairments is so low that extensive neurological evaluation is usually unnecessary.

33 SPINE Volume 26, Number 5, pp E93 E113

34 Lumbar Disc Herniation Radicular pain: high sensitivity - absence makes a clinically important lumbar disk herniation unlikely With significant disc herniation, leg pain > back pain Peak incidence occurs between the ages of 30 and 55 years

35 Lumbar Disc Herniation cont. Symptomatic disk herniation tethers the affected nerve root Most common levels: L4-5, L5-S1 Pain from stretching the nerve = straight leg test Positive straight leg sign = reproduces pain between 30 and 60 of leg elevation Crossed straight leg sign = straight leg raising is performed on contralateral leg, reproducing pain Less sensitive, but highly specific

36 Dermatomes and Myotomes Level Sensory Motor L2-3 Anteromedial thigh Hip flexion L4 Medial Malleolus Dorsiflexion foot L5 Web space b/w 1st and 2nd toes 1 st toe flexion S1 Lateral foot and sole Plantar flexion

37 Spinal Stenosis

38 Spinal Stenosis Characteristic history = neurogenic claudication Pain in the legs and occasionally neurologic deficits after walking Symptomatic while standing, may increase with cough/sneeze Normal arterial pulses compared to vascular claudication Increased pain on spine extension is typical of stenosis vs. flexion is usually most painful with herniated disks Walking uphill is easier than walking down hill Walking with walker or shopping cart easier, forward flexion.

39 Location of pain Neurogenic Thighs, calves, back and rarely buttocks Vascular Buttocks or calves Quality of pain Burning, cramping Cramping Aggravating Relieving Erect position, ambulation Squatting, bending forward, sitting Leg Pulses and BP Usually normal Skin / Trophic changes Usually absent Leg exercises Rest Decreased BP and pulses Often present (pallor, cyanosis, less hair)

40 Axial Low Back Pain Pain limited to the area of the lumbo-sacral junction Facet arthropathy 15% Degenerative disc disease 40% Sacroiliac arthropathy 15% Schwarzer et al 1993

41 Low Back Pain - Multifactorial Spine 65% 7.5% 8% 1.5% SI Joint 5% 0.5% Hip 2.5%

42 Facet Arthropathy Anesthesiology , Vol.106,

43 Facet Arthropathy

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45 When to order imaging Choosing Wisely initiative ABIM ASA/ACP/AAFP: Avoid in first 6 weeks, unless red flags, concerning history History of cancer AAA Progressive neuro deficit Concern for infection Avoid cost, exposure to radiation Imaging without history/exam does not improve outcome and increases cost

46 Mafi JN, McCarthy EP, Davis RB, Landon BE. Worsening Trends in the Management and Treatment of Back Pain. JAMA Intern Med.2013;173(17):

47 TREATMENT

48 Analgesics NSAIDS 1 st line Muscle relaxants Anticonvulsants Antidepressants Opioids Chou R, Qaseem A, Snow V, Casey D, Cross JT, Shekelle P, et al. Diagnosis and Treatment of Low Back Pain: A Joint Clinical Practice Guideline from the American College of Physicians and the American Pain Society. Ann Intern Med. 2007;147:

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50 LBP and Opioids Retrospective cohort study of WC claims with acute disabling LBP Objective: examine the association between early opioid use for acute LBP and outcomes at 2 years Sample: 8443 claimants from 1/ /2003 Conclusion: Opioids counterproductive to recover Longer length of disability More costs Increased risk of surgery Ongoing opioid use Webster et al. Relationship between early opioid prescribing for acute occupational low back pain and disability duration, medical costs, subsequent surgery and late opioid use. Spine 2007 Sep 1;32(19):

51 Opioids Have Clear Disadvantages A systematic review found aberrant drug-taking behaviors in up to 24% patients prescribed opioids for LBP May be appropriate for short-term use for severe, acute exacerbations; use with caution for long-term treatment of chronic LBP Should restrict to patients not highly vulnerable to drug dependence, abuse, addiction Chou R, et al. Diagnosis and Treatment of Low Back Pain: A Joint Clinical Practice Guideline from the American College of Physicians and the American Pain Society. Ann Intern Med. 2007;147:

52 Characteristics of Initial Prescription Episodes and Likelihood of Long-Term Opioid Use United States, Early opioid prescribing for opioid-naive patients associated with longterm use Chances of chronic use starts to increase after 3rd day supplied, rapid rise thereafter Sharpest increase after 5th and 31st day of therapy 2nd Rx or refill 700 MME cumulative dose Initial 10 or 30 day supply Highest probability of continued use at 1 and 3 years Started on long acting opioid Tramadol Shah A, Hayes CJ, Martin BC. Characteristics of Initial Prescription Episodes and Likelihood of Long-Term Opioid Use United States, MMWR Morb Mortal Wkly Rep 2017;66:

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54 National Overdose Deaths Number of Deaths from Prescription Opioid Pain Relievers 20,000 Total Female Male 15,000 10,000 5,000 0 Source: National Center for Health Statistics, CDC Wonder

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57 CDC Guideline - Opioids for Chronic Pain Use non-opioid therapies Exercise Cognitive behavioral therapy Non-opioid pharmacologic therapies, ie. NSAIDS Start low and go slow lowest possible effective dose start with IR vs. ER/long-activing smallest quantity Follow-up regularly monitor determine if benefit > harm; if not, work to taper/discontinue Dowell D, Haegerich TM, Chou R. CDC Guideline for Prescribing Opioids for Chronic Pain United States, MMWR Recomm Rep 2016;65(No. RR-1):1 49

58 NSAIDS and Acetaminophen NSAIDS effective for short-term symptom relief for acute and chronic low back pain Effect size small Exposure to selective COX-2 inhibitors - risk of MI APAP ineffective on both pain and disability outcomes for LBP in immediate and short term Not clinically superior to placebo on both pain and disability outcomes for osteoarthritis Roelofs PD, Deyo RA, et al. Nonsteroidal anti-inflammatory drugs for low back pain: an updated Cochrane review. Spine (Phila Pa 1976) Jul 15;33(16): Machado GC, et al. Efficacy and safety of paracetamol for spinal pain and osteoarthritis: systematic review and meta-analysis of randomised placebo controlled trials BMJ 2015; 350 :h1225\

59 Antidepressants No difference between antidepressant and placebo for LBP, no difference between types of antidepressants Associated with higher risk of adverse events vs. placebo drowsiness dry mouth dizziness Because of questionable benefits and known side effects, tricyclic antidepressants, SNRIs are not a first-line option Chou R, et al. Diagnosis and Treatment of Low Back Pain: A Joint Clinical Practice Guideline from the American College of Physicians and the American Pain Society. Ann Intern Med. 2007;147:

60 Muscle Relaxants No difference in short-term muscle spasm between cyclobenzaprine and placebo Skeletal muscle relaxants may be considered as adjunctive therapy to analgesics in patients with acute exacerbations of chronic low back pain Chou R, et al. Diagnosis and Treatment of Low Back Pain: A Joint Clinical Practice Guideline from the American College of Physicians and the American Pain Society. Ann Intern Med. 2007;147:

61 Benzodiazepines Tetrazepam (not available in US) more effective than placebo for short-term pain intensity after 5 to 7 days and overall improvement Only trial evaluating BZDs used in US, no difference between diazepam and placebo for muscle spasm Limited evidence on efficacy and potential for addiction and abuse - BZDs should not be used for long-term treatment of chronic low back pain Chou et al, Annals of Internal Medicine Volume 147 Number 7

62 Gabapentin Small, statistically significant improvements in pain with movement and leg pain, titrated to 1200 mg/day mg/day more effective than placebo, but lacked a double-blind design. Adverse events Drowsiness (6%) Loss of energy (6%) Dizziness (6%) Chou et al, Annals of Internal Medicine Volume 147 Number 7

63 Gabapentin for Spinal Stenosis N=55, open label trial Pseudoclaudication and spinal stenosis on imaging Titrated to 2400 mg/day, plus supervised exercise therapy, lumbar supports, NSAIDs Moderately improved mean pain scores at four months (2.9 versus 4.7 on a 0 to 10 scale). Chou et al, Annals of Internal Medicine Volume 147 Number 7

64 Gabapentin abuse & misuse At risk: hx of or current substance use d/o, opioid, bzds and other sedatives; psychiatric d/o Abused by up 68% of opioid abusers Self administering excessive amounts to achieve euphoria, MJ like high, helps alleviate withdrawal symptoms Pure gabapentinoid OD safe, but often found on postmortem toxicology screens Bonnet U, Scherbaum N. Eur Neuropsychopharmacol Dec;27(12): Evoy KE, Morrison MD, Saklad SR. Drugs Mar;77(4):

65 Exercise Therapy Systematic review of 43 trials Slightly to moderately superior to no treatment for pain relief, though there were no significant differences in functional outcomes. Surgical decompression similar to PT among patient with lumbar spinal stenosis who were surgical candidates. Early PT reduces cost by >70% in the first year when compared to imaging Delitto A,et al. Ann of Internal Medicine 2015 Fritz JM, et al. Health Serv Res Dec;50(6):

66 Yoga Randomized trial of 101 patients, viniyoga improved functional status and symptoms at 12 weeks compared to a back exercise class, or a self-care book At 26 weeks, yoga equivalent to exercise, remained superior to self-care book. Yoga associated with decreased medication use compared to exercise or the self-care book. Yoga for nonspecific clbp noninferior to PT for function and pain compared to education book.

67 Acupuncture Two systematic reviews found acupuncture moderately more effective than no treatment for short-term pain relief and improvement in function More effective than sham acupuncture for pain relief, but not for improvement in function However, two well-blinded trials found no difference between acupuncture and sham acupuncture for either pain or function

68 Spinal Manipulations Moderately superior to sham manipulation or therapies thought to be ineffective No advantage compared to other interventions: Analgesics physical therapy Other systematic reviews similarly concluded that spinal manipulation has a minimal beneficial effect

69 When to Refer Cauda equina syndrome send to ED Neuromotor deficits Failing to respond to conservative therapies Patients at risk for developing chronic pain

70 Conclusion Everyone gets back pain Most people get better, but need to identify high risk patients for clbp Surgical evaluation for CES, any motor weakness Pain management referral for those at risk for chronic pain, not responding to conservative measures