Clinical Commander

All dossiers
symptom.back_pain.ed.v1

Acute back pain (ED red-flag workup)

symptomacuteundifferentiatedadultacute
Start encounter →Print handoutPRODUCTION

Phase C shard-3-neuro-sym wave-7 expansion (2026-05-14) — pattern-matches symptom.chest_pain.ed_undifferentiated.v1 (be7b7d2f) and symptom.dyspnea.ed.v1 / symptom.syncope.ed.v1 (e5b52910). Engine scope: ED triage focused on red-flag rule-out for acute back pain. Most cases (>85%) are mechanical/MSK; engine job is NOT to miss the catastrophic minority (cauda equina, SEA, osteomyelitis, metastatic compression, vertebral fracture, AAA, dissection, urosepsis). SNNOOP10 red-flag mnemonic anchored in RED_FLAGS phase + setting playbook required_assessments (Saddle anesthesia / Neurologic deficit + bowel-bladder / Neoplasm history / Onset sudden + severe / Older >50 / Persistent fever / Pattern progressive / Pain at night / Position-related neurologic / Pregnancy). Downstream routing: vasc.aaa.v1 (AAA leak), cardio.aortic-dissection.core.v1 (thoracic dissection), id.sepsis.core.v1 (urosepsis), uro.urolithiasis.v1 (renal colic), neuro.ischaemic-stroke.v1 (cord-stroke variant), symptom.abdominal_pain.ed.v1 (visceral overlay), symptom.falls.v1 (geriatric falls with fracture). Bayesian linkage (LR+, LR−, T_treat, T_test) lives in companion depth bundle _briefs/symptom.back_pain.ed.v1.depth.md — schema has no first-class likelihood-ratio field. 10 sibling-differentiation rows cover the key look-alikes (AAA / dissection / urosepsis / urolithiasis / cord-stroke / visceral abdominal / falls fracture / cirrhotic referred / NSTEMI / PE). 12 severity triggers (≥8 per spec): cauda_equina_syndrome + spinal_epidural_abscess + vertebral_osteomyelitis + metastatic_cord_compression + vertebral_compression_fracture + aaa_leak_with_back_pain + thoracic_aortic_dissection_back + pyelonephritis_urosepsis + renal_colic_urolithiasis + progressive_neuro_deficit + mechanical_back_pain_no_red_flag + spontaneous_epidural_hematoma. Schema-blocked emitted: workup.back_pain + SNNOOP10 checklist + Genant grading + Davis SEA clinical-prediction-rule + STIR/T2 MRI protocols + STarT Back — none in clinical-tools-registry; manual application in setting playbook + ticketed in shard-3 state file. Regimen_axes intentionally empty — engine is triage-only. Supportive drug actions (acetaminophen / NSAID / cyclobenzaprine / opioid short course / vanc + ceftriaxone for SEA / dexamethasone for cord compression / esmolol-labetalol for dissection) live in setting_playbooks.ed.drug_actions; definitive treatment is owned by downstream consult-based pathways. Setting playbook: single `ed` per user spec — outpatient chronic back pain workup is a future engine. SCAFFOLDED status: no workup.back_pain in clinical-tools-registry; PRODUCTION audit would fail. Will promote once registry entries land.

Entry points (10)

  • symptom
    Acute back pain (low / thoracic / cervical) — drives red-flag screen first (ACP Qaseem 2017 PMID 28192789)
    acute_back_pain
  • symptom
    Back pain with sciatica or radiculopathy — assess motor/sensory deficit per dermatome (ACP 2017)
    back_pain_with_radiculopathy
  • symptom
    Back pain + motor weakness or saddle anesthesia or bowel/bladder dysfunction → SUSPECT CAUDA EQUINA — STAT MRI (Kuris 2015 PMID 26416327)
    back_pain_with_neuro_deficit
  • symptom
    Back pain + fever + IVDU or immunocompromise → SUSPECT spinal epidural abscess — STAT MRI gad (Bond 2016 PMID 28121397)
    back_pain_with_fever
  • symptom
    Back pain + known cancer + neuro deficit or night pain → SUSPECT metastatic cord compression — STAT MRI + steroid + RT
    back_pain_with_cancer_hx
  • symptom
    Back pain + osteoporosis + minor trauma → SUSPECT vertebral fracture (Genant grading PMID 20308793)
    back_pain_with_minor_trauma
  • symptom
    Back pain + hypotension + flank/midline tenderness + age >65 → SUSPECT AAA leak (Sakalihasan 2018) — STAT CTA
    back_pain_with_hypotension
  • symptom
    Tearing thoracic back pain + BP differential between arms → SUSPECT aortic dissection — STAT CTA chest
    thoracic_back_pain_tearing
  • symptom
    Back/flank pain + dysuria + hematuria + fever → SUSPECT pyelonephritis or renal colic — UA + CT KUB
    back_pain_with_urinary_features
  • vital_abnormality
    SBP <90 OR HR >120 with back pain — life-threat triage (AAA leak / dissection / urosepsis)
    hemodynamic_instability_back

Required inputs (32)

  • agerequired
    demographic • used at CONTEXT
    Age >50 with new back pain raises red-flag prior (malignancy, fracture, AAA, dissection) (ACP 2017 PMID 28192789)
  • sexrequired
    demographic • used at CONTEXT
    Pregnancy raises differential (preeclampsia, abruption, MSK from biomechanics); reproductive-age females need β-hCG before imaging
  • pain_onset_timerequired
    symptom • used at FRAME
    Sudden maximal-intensity onset = AAA / dissection / acute fracture; gradual = inflammatory / mechanical (Sakalihasan 2018; ACP 2017)
  • pain_locationrequired
    symptom • used at FRAME
    Cervical / thoracic / lumbar; midline vs paraspinal vs flank — anchors differential (mechanical vs visceral vs aortic) (ACP 2017)
  • pain_radiationrequired
    symptom • used at ENTRY
    Sciatica (L4-S1 dermatome) = radiculopathy; anterior thigh = L2-L4; chest = thoracic dissection; groin = AAA or urolithiasis (ACP 2017)
  • pain_qualityrequired
    symptom • used at FRAME
    Tearing = dissection / AAA; constant + worse at night = malignancy / infection; mechanical worse with movement / better with rest = MSK (ACP 2017; Berbari IDSA PMID 28118470)
  • red_flag_saddle_anesthesiarequired
    symptom • used at ENTRY
    Saddle anesthesia (S2-S4) is the most specific feature of cauda equina syndrome — STAT MRI threshold (Kuris 2015 PMID 26416327)
  • red_flag_bowel_bladder_dysfunctionrequired
    symptom • used at ENTRY
    New urinary retention / fecal incontinence / overflow urinary incontinence — late but specific cauda equina feature (Kuris 2015)
  • red_flag_bilateral_leg_weaknessrequired
    symptom • used at ENTRY
    Bilateral lower extremity weakness or paresthesia raises cauda equina prior dramatically (Kuris 2015)
  • red_flag_feverrequired
    symptom • used at ENTRY
    Persistent fever + back pain + IVDU or immunocompromise → spinal epidural abscess (Bond 2016 PMID 28121397; Berbari IDSA 2015 PMID 28118470)
  • red_flag_night_painrequired
    symptom • used at ENTRY
    Night pain or pain at rest unrelieved by position raises malignancy / infection prior (ACP 2017)
  • red_flag_progressive_neurorequired
    symptom • used at ENTRY
    Progressive motor weakness / progressive sensory loss / progressive bowel-bladder symptoms is RED-FLAG (Kuris 2015; ACP 2017)
  • sbprequired
    vital • used at CONTEXT
    Hypotension flags AAA leak / dissection / urosepsis (Sakalihasan 2018; SSC 2026)
  • hrrequired
    vital • used at CONTEXT
    Tachycardia in volume loss / dissection / sepsis
  • temprequired
    vital • used at CONTEXT
    Fever raises infection prior (SEA / osteomyelitis / pyelonephritis) (Berbari IDSA 2015 PMID 28118470)
  • bp_both_arms
    vital • used at CONTEXT
    >20 mmHg differential between arms suggests thoracic aortic dissection (AHA 2022)
  • cancer_historyrequired
    history • used at CONTEXT
    Known malignancy (breast, lung, prostate, renal, multiple myeloma, lymphoma) — new back pain warrants STAT MRI for metastatic cord compression
  • ivdu_or_immunocompromiserequired
    history • used at CONTEXT
    IVDU / immunosuppression / diabetes / chronic steroid / dialysis / recent spinal procedure → SEA prior (Bond 2016 PMID 28121397)
  • osteoporosis_or_steroid_userequired
    history • used at CONTEXT
    Osteoporosis or chronic glucocorticoid use → fragility vertebral fracture prior (Genant PMID 20308793)
  • recent_traumarequired
    history • used at CONTEXT
    High-energy trauma → unstable fracture risk; low-energy in osteoporosis → compression fracture
  • aortic_risk_factorsrequired
    history • used at CONTEXT
    Smoking + HTN + male + >65 + family history → AAA / dissection (Sakalihasan 2018 PMID 23335416)
  • anticoagulant_userequired
    history • used at CONTEXT
    Anticoagulation raises spontaneous epidural hematoma prior (rare but mimics SEA / cauda equina)
  • pregnancy_or_postpartumrequired
    history • used at CONTEXT
    Pregnancy → preeclampsia / HELLP; postpartum → cortical vein thrombosis with referred back pain
  • cbc_with_diffrequired
    lab • used at INITIAL_WORKUP
    Leukocytosis in SEA / osteomyelitis / pyelonephritis; anemia in malignancy or bleeding (Bond 2016)
  • esr_crprequired
    lab • used at INITIAL_WORKUP
    ESR + CRP screening for SEA / osteomyelitis — CRP >50 or ESR >50 raises suspicion; high NPV when both normal (Berbari IDSA 2015 PMID 28118470; Bond 2016)
  • blood_cultures
    lab • used at INITIAL_WORKUP
    Blood cultures × 2 BEFORE antibiotics for SEA / osteomyelitis / urosepsis (Berbari IDSA 2015)
  • urinalysisrequired
    lab • used at INITIAL_WORKUP
    UA for hematuria (urolithiasis) / pyuria + nitrites (pyelonephritis); β-hCG if reproductive-age female
  • creatininerequired
    lab • used at INITIAL_WORKUP
    eGFR for contrast decisions (CTA / MRI gad) and dosing
  • lumbar_spine_xray
    imaging • used at BRANCHING_WORKUP
    Plain films are LOW-yield for soft tissue / SEA / cauda equina but useful for compression fracture screen (ACP 2017)
  • mri_spine_with_gadolinium
    imaging • used at BRANCHING_WORKUP
    GOLD STANDARD for cauda equina / SEA / osteomyelitis / metastatic compression — STAT, gadolinium-enhanced (Kuris 2015; Bond 2016; Berbari IDSA 2015)
  • cta_chest_or_abdomen
    imaging • used at BRANCHING_WORKUP
    CTA chest for thoracic dissection (AHA 2022); CTA abdomen for AAA (Sakalihasan PMID 23335416)
  • ct_kub_non_contrast
    imaging • used at BRANCHING_WORKUP
    CT KUB for urolithiasis (flank pain + hematuria)

12-phase flow (12)

  1. 1FRAME
    Pain onset, location, quality; SNNOOP10 red-flag screen anchored (ACP 2017 PMID 28192789; Stochkendahl PMID 33558739)
    inputs: pain_onset_time, pain_location, pain_quality
    advance: pain characterized + red-flag screen run
  2. 2ENTRY
    Capture saddle anesthesia, bowel/bladder dysfunction, bilateral leg weakness (cauda equina); fever (SEA); night pain (malignancy/infection); progressive neuro (Kuris 2015; Bond 2016)
    inputs: pain_radiation, red_flag_saddle_anesthesia, red_flag_bowel_bladder_dysfunction, red_flag_bilateral_leg_weakness, red_flag_fever, red_flag_night_pain, red_flag_progressive_neuro
    advance: red-flag pattern captured
  3. 3CONTEXT
    Age, sex, pregnancy, cancer hx, IVDU/immunocompromise, osteoporosis/steroid use, trauma, aortic risks, anticoag, vitals + temp + BP both arms (ACP 2017; Berbari IDSA 2015; Genant)
    inputs: age, sex, sbp, hr, temp, bp_both_arms, cancer_history, ivdu_or_immunocompromise, osteoporosis_or_steroid_use, recent_trauma, aortic_risk_factors, anticoagulant_use, pregnancy_or_postpartum
    advance: context complete
  4. 4RED_FLAGS
    SNNOOP10: Saddle anesthesia / Neurologic deficit + bowel-bladder / Neoplasm history / Onset sudden + severe / Older >50 unusual / Persistent fever / Pattern progressive / Pain at night / Position-related neurologic / Pregnancy (ACP 2017; USPSTF 2018 PMID 29457591; Stochkendahl 2018)
    advance: red flags screened + STAT MRI threshold determined
  5. 5INITIAL_WORKUP
    CBC, ESR, CRP, UA, creatinine, blood cultures if febrile; ECG if thoracic pain + dissection workup; β-hCG if reproductive-age female (Berbari IDSA 2015; Bond 2016)
    inputs: cbc_with_diff, esr_crp, blood_cultures, urinalysis, creatinine
    actions: panel.cbc, panel.renal, panel.inflammation
    advance: initial workup reviewed
  6. 6BRANCHING_WORKUP
    Pivot on red-flag pattern: cauda equina / SEA / osteo / metastatic → STAT MRI gad; AAA / dissection → CTA chest or abdomen; urolithiasis → CT KUB non-contrast; pyelonephritis → UA + CT if complicated; compression fracture → lumbar XR / MRI if neuro deficit (Kuris 2015; Bond 2016; Sakalihasan 2018)
    inputs: lumbar_spine_xray, mri_spine_with_gadolinium, cta_chest_or_abdomen, ct_kub_non_contrast
    advance: branching workup pivots to disposition route
  7. 7DIFFERENTIAL
    Mechanical/MSK (>85%) / sciatica + radiculopathy (~10-15%) / cauda equina (~1/1000-5000 in ED back pain) / spinal epidural abscess (~0.2-1.2/10000) / vertebral osteomyelitis / metastatic compression (~5% of cancer patients) / vertebral fracture (osteoporotic) / AAA leak (~0.1% of ED back pain) / aortic dissection (~0.3%) / pyelonephritis / renal colic / spinal stenosis (chronic — neurogenic claudication) / ankylosing spondylitis / fibromyalgia (chronic; exclusion) (ACP 2017 PMID 28192789; Stochkendahl 2018 PMID 33558739)
    advance: differential ranked with pre-test priors documented
  8. 8RISK_STRATIFICATION
    SNNOOP10 → STAT MRI threshold; SEA-clinical-prediction (Davis 2011: any of fever + IVDU + recent procedure + immunocompromise + CRP/ESR elevation → MRI); Genant grading for compression fracture (PMID 20308793); SSC 2026 sepsis screen for urosepsis (ACP 2017)
    inputs: age
    advance: red-flag risk stratified + imaging decision made
  9. 9TREATMENT
    Supportive: analgesia (acetaminophen first-line per ACP 2017; NSAIDs second-line — caution renal/GI; opioids for severe acute only — short course); muscle relaxants for spasm (cyclobenzaprine short course); empiric antibiotics IF SEA/osteomyelitis confirmed (vancomycin + ceftriaxone OR vanco + cefepime per IDSA 2015 PMID 28118470); IV dexamethasone 10 mg if metastatic cord compression suspected + STAT MRI + RT/neurosurg (ACP 2017; USPSTF 2018; Stochkendahl 2018)
    advance: supportive Rx initiated; definitive Rx awaits imaging + consult
  10. 10DISPOSITION
    Cauda equina → STAT MRI + neurosurg + OR decompression within 24-48 h; SEA → STAT MRI + neurosurg + IDSA-guided antibiotics; osteomyelitis confirmed → admit + IDSA antibiotics ± biopsy; metastatic compression → admit + steroid + RT/neurosurg; vertebral fracture stable → discharge with PT/brace + outpatient; AAA leak → vasc.aaa.v1; dissection → cardio.aortic-dissection.core.v1; pyelonephritis with sepsis → id.sepsis.core.v1; urolithiasis → uro.urolithiasis.v1; mechanical MSK with no red flags → discharge with PCP follow-up + return precautions (ACP 2017)
    advance: disposition assigned + downstream handoff complete
  11. 11MONITORING
    Serial neuro exam q4-6h on observation; pain reassessment; recheck red flags if symptom evolution; serial ESR/CRP trending for confirmed SEA/osteo (Berbari IDSA 2015)
    advance: evolution captured
  12. 12FOLLOWUP
    Mechanical/MSK discharged: PCP within 1-2 weeks; conservative care (early mobilization, heat, NSAID, PT); avoid bed rest >2 days; return precautions (worsening pain, new neuro deficit, fever, bowel/bladder, weight loss); ACP 2017 + USPSTF 2018 endorse exercise / PT / cognitive-behavioral / spinal manipulation for subacute
    advance: discharge bundle prescribed + follow-up scheduled