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Back Pain, Emergency Medicine

Basics

Description

- Nonspecific musculoligamentous source (great majority) (e.g., muscle, ligament, fascia) - Herniation of the nucleus pulposus - Degenerative joints or discs - Spinal stenosis - Anatomic abnormalities-especially spondylolisthesis - Fractures from trauma and osteoporosis - Underlying systemic diseases (minority): - Neoplasm - Infections - Vascular (dissection, aneurysm, and thrombosis) - Renal - GI - Pelvic organ pathology

- Can assist with focusing and narrowing differential diagnosis. Helps rule out concerning pathology for pain: - Intensity - Quality - Location and radiation - Onset - Exacerbating or remitting factors - Social or psychological factors - Response to previous therapy

- Risk factors for serious disease: - Fever - Constitutional symptoms - Trauma - Age >60 yr - History of cancer: - Especially those that metastasize to bone

- Chronic steroid use - IV drug use - Recent instrumentation or bacteremia - Night pain

- Urinalysis for suspected: - UTI/pyelonephritis - Prostatitis

- CT: - Secondary modality for diagnosis of abscess, cancer, or massive disc when MRI unavailable - Test of choice in imaging potential unstable fractures - Excellent sensitivity to evaluate vascular etiology in stable patient

- NSAIDs: - Musculoligamentous pain - Renal colic - Similar benefits as APAP but less optimal side-effect profile

- Acupuncture: - Controversial, probable benefit for chronic musculoskeletal pain - No clear benefit over other modalities - Trigger point therapy with minimal to no evidence of benefit for chronic LBP not studied for acute

  • Low back pain (LBP):Refers to pain in the area between the lower rib cage and the gluteal folds, often with radiation into the thighs
  • Sciatica:Pain in the distribution of the lower lumbar spinal rootsMay be accompanied by neurosensory and motor deficits
  • Pain classification:Acute: <6 wkSubacute: 6-12 wkChronic: >12 wk

Etiology

  • Nonspecific musculoligamentous source (great majority) (e.g., muscle, ligament, fascia)
  • Herniation of the nucleus pulposus
  • Degenerative joints or discs
  • Spinal stenosis
  • Anatomic abnormalities-especially spondylolisthesis
  • Fractures from trauma and osteoporosis
  • Underlying systemic diseases (minority):NeoplasmInfectionsVascular (dissection, aneurysm, and thrombosis)RenalGIPelvic organ pathology

Diagnosis

Signs and Symptoms

  • Musculoligamentous:Poorly localized and dull back/gluteal pain without radiation past the knee.Usually no objective neurologic signs.Back spasm is a variable and poorly reproducible finding.
  • Sciatica:Sharp, shooting, well-localized painLeg complaints often greater than backMay present withasymmetric deep tendon reflexesdecreased sensation in a dermatomal distributionobjective weakness
  • Massive central disc herniation (cauda equina):Decreased perineal sensationUrinary retention with overflow incontinenceFecal incontinence
  • Infectious processes:FeverLocalized percussion tenderness of the vertebral bodies
  • Bony lesion:Continuous pain that does not change with restConstitutional symptoms
  • Vascular etiology:Severe, often "ripping or tearing"Ł painMay be associated with cold or insensate extremities

History

  • Can assist with focusing and narrowing differential diagnosis. Helps rule out concerning pathology for pain:IntensityQualityLocation and radiationOnsetExacerbating or remitting factorsSocial or psychological factorsResponse to previous therapy
  • Risk factors for serious disease:FeverConstitutional symptomsTraumaAge >60 yrHistory of cancer:Especially those that metastasize to boneChronic steroid useIV drug useRecent instrumentation or bacteremiaNight pain

Physical Exam

  • Fever
  • Spasm or soft tissue tenderness is a poorly reproducible finding:Vertebral tenderness sensitive but nonspecific for infection
  • Straight leg raise-elevating the leg while supine reproduces sciatic symptoms:Ipsilateral raise highly sensitive but not specificCrossed leg raise highly nonspecific but insensitive
  • Ankle and great toe dorsiflexion and ankle plantar flexion (L5, S1 nerve roots)
  • Ankle deep tendon reflexes (S1)
  • Dermatomal sensory exam:Assess for saddle anesthesia
  • Rectal sphincter tone

Essential Workup

  • Thorough history and physical exam, including detailed neurologic and vascular exam
  • No specific tests are needed for uncomplicated musculoligamentous or sciatic pain
  • Rapid diagnostic testing and vascular consultation concerning aortic etiology

Diagnosis Tests & Interpretation

Lab

  • Urinalysis for suspected:UTI/pyelonephritisProstatitis
  • ESR:Highly sensitive, though nonspecific for infectious or inflammatory etiologiesUsed for screening to help rule out disease

Imaging

  • Lumbosacral radiograph:Significant traumaAge >50-60 yrHistory or signs/symptoms of cancerFeverIV drug userPain at restSuspicion of inflammatory etiologyPain that does not improve after 4 wk
  • Bedside US:Full bladder suggests urinary retentionAbdominal aortic aneurysm (AAA)Abdominal CT if patient stable
  • MRI:Suspicion of abscess:Fever, immunocompromised, IVDA, history of bacteremiaSuspicion of metastatic tumor:Systemic cancer, weight lossSuspicion of hematoma:Anticoagulation, recent spinal anesthesiaRapidly progressing neurologic symptomsUrinary retention or fecal incontinence associated with back pain
  • CT:Secondary modality for diagnosis of abscess, cancer, or massive disc when MRI unavailableTest of choice in imaging potential unstable fracturesExcellent sensitivity to evaluate vascular etiology in stable patient

Differential Diagnosis

  • Spinal origins-in the majority of patients no precise anatomic site is discovered:Musculoligamentous (majority)DiscogenicFractureSpondylolisthesisAnkylosing spondylitisOsteomyelitisEpidural abscess/hematomaNeoplasm
  • Nonspinal causes:AAAProstatitisUpper UTIAbdominal neoplasmRenal colicAortic dissection

Treatment

Pre-Hospital

  • Immobilization is not generally recommended for nontraumatic pain.
  • Rapid transport for vascular concerns

Ed Treatment/Procedures

  • NSAIDs:Musculoligamentous painRenal colicSimilar benefits as APAP but less optimal side-effect profile
  • APAP: Considered 1st-line therapy for mild-to-moderate painModerate but conflicting evidence for benefit of NSAID and acetaminophen combination over each individually in postoperative painAPAP and NSAIDs not effective for sciatica pain
  • Muscle relaxants:Cyclobenzaprine, methocarbamol, carisoprodol, or tizanidineBenefits must be balanced by side effects, mostly sedation, dizziness, and dry mouth
  • Benzodiazepines:No clear difference from skeletal muscle relaxantsLikely higher risk profile for addiction
  • Narcotics:A reasonable (3-5 days) course may be given for severe pain not relieved by anti-inflammatory or APAP. Effective for neuropathic painRisk benefit profile should be considered and discussed with patient
  • Corticosteroids:No benefit in radicular or nonradicular back pain
  • Spinal manipulation:A short course (<2 wk) may be helpful in acute LBP without sciatica
  • Physical therapy/exercise:No clear consensus for indicationsMay be helpful in symptomatic relief, preventing further episodes and teaching patients
  • Acupuncture:Controversial, probable benefit for chronic musculoskeletal painNo clear benefit over other modalitiesTrigger point therapy with minimal to no evidence of benefit for chronic LBP not studied for acute
  • Massage:May be beneficial when combined with exercises and education
  • Heat/cold therapy:Limited evidence to support that heat wrap therapy may help reduce pain and disability for patients with back pain <3 mo. Improved as adjunct to exercise.
  • Bed rest:Unhelpful to speed recovery and may impede improvement. If patient requires bed rest acutely or is symptomatically improved, 1 or 2 days may be recommended.
  • Back exercises:Unlikely to be useful in acute phase; may assist with prevention of future episodes
  • Expected recovery to pain-free state:Conflicting data, mostly in non-ED setting~33% within 1 wk~90% within 6-8 wkLow SES, female sex, baseline disability and chronic LBP significant for worse functional outcome at 1 and 3 wkNewer ED data suggests functional limitation in 50% of patients with pain at 3 mo.
  • Recurrence is common: ~40%

Medication

First Line

  • Acetaminophen: 500 mg (peds: 10-15 mg/kg, do not exceed 5 doses/24h) PO q4-6h, do not exceed 4 g/24h
  • Hydrocodone/acetaminophen: 5/500 mg PO q4-6h
  • Ibuprofen: 600-800 mg PO q6-8h (peds: 10 mg/kg q6h)
  • Naproxen: 250-500 mg PO q12h
  • Oxycodone/acetaminophen: 5/500 mg PO q4-6h

Second Line

  • Cyclobenzaprine: 5-10 mg PO TID. Caution patient regarding drowsiness.
  • Methocarbamol: 500-1,500 PO q6h. Caution patient regarding drowsiness.
  • Valium: 5-10 mg PO q8h
  • You may combine 1st- and 2nd-line therapies but side-effect profile will increase

Follow-Up

Disposition

Admission Criteria

  • Severe pain with inability to ambulate
  • Pain unresponsive to ED management
  • Progressive neurologic deficits
  • Signs of cauda equina syndrome
  • Infectious, vascular, or neoplastic etiologies

Discharge Criteria

Uncomplicated presentation with ability to control pain and ambulate á

  • Maintain a high suspicion for serious disease including vascular etiology, neoplasm, or infection.
  • Have a low threshold for imaging or diagnostic testing.
  • Follow up patients on NSAIDS or opioids more carefully for complications or adverse events related to therapy.
  • Back pain is unusual in the pediatric patient; a high suspicion for an infectious etiology must be maintained.
  • For musculoligamentous pain, a single trial found that Ibuprofen provides good pain control with a low side-effect profile.

Limited evidence suggests that strengthening and pelvic tilt exercises combined with routine prenatal care may have benefit in treating back pain; unclear if they prevent pain á

Issues for Referral

Urgent neurosurgical or orthopedic consultation for definite diagnosis or high suspicion for abscess or lesion (disc, neoplasm, or other) with rapidly progressive objective neurologic findings á

Follow-Up Recommendations

  • Uncomplicated back pain: PCP in 1-2 wk
  • New sciatica without neurologic findings: PCP or specialist in 7-10 days
  • Complicated with sensory findings only or minimal motor symptoms: 24-48 hr
  • Marked or rapidly progressive motor symptoms, or bowel/bladder findings warrant specialist consultation in the ED or transfer if unavailable.

Pearls and Pitfalls

  • Consider MRI for history of IVDA to rule out epidural abscess or if concerns of nonbony spinal metastases.
  • Elderly with minimal trauma may sustain fractures.
  • Consider vascular etiology in elderly patients with 1st-time presentation of back pain.
  • Advise patients that this is often a prolonged course and they should not expect rapid resolution.
  • Opioids should be limited to a short course from the ED.

Additional Reading

  • Cantrill áSV, Brown áMD, Carlisle áRJ, et al. American College of Emergency Physicians Opioid Guideline Writing Panel. Clinical policy: Critical issues in the prescribing of opioids for adult patients in the emergency department. Ann Emerg Med. 2012;60(4):499-525.
  • Davies áRA, Maher áCG, Hancock áMJ. A systematic review of paracetamol for non-specific low back pain. Eur Spine J. 2008;17:1423-1430.
  • Friedman áBW, O'Mahony áS, Mulvey áL, et al. One-week and 3-month outcomes after an emergency department visit for undifferentiated musculoskeletal low back pain. Ann Emerg Med. 2012;59(2):128-133.
  • Roelofs áPD, Deyo áRA, Koes áBW, et al. Nonsteroidal anti-inflammatory drugs for low back pain. Spine. 2008;33(16):1766-1774.
  • Waterman áBR, Belmont áPJ Jr, Schoenfeld áAJ. Low back pain in the United States: Incidence and risk factors for presentation in the emergency setting. Spine J. 2012;12(1):63-70.

Codes

ICD9

  • 724.2 Lumbago
  • 724.3 Sciatica
  • 724.5 Backache, unspecified

ICD10

  • M54.5 Low back pain
  • M54.9 Dorsalgia, unspecified
  • M54.30 Sciatica, unspecified side
  • M54.40 Lumbago with sciatica, unspecified side
  • M54.31 Sciatica, right side
  • M54.3 Sciatica
  • M54.41 Lumbago with sciatica, right side
  • M54.42 Lumbago with sciatica, left side
  • M54.4 Lumbago with sciatica

SNOMED

  • 161891005 backache (finding)
  • 279039007 low back pain (finding)
  • 278862001 acute low back pain (finding)
  • 278860009 chronic low back pain (finding)
  • 23056005 Sciatica (disorder)