Stethopedia | Approach

Approach to

Dyspnea

Look at the patient first: support breathing and act on airway threats and respiratory failure. Then sort the cause by where the problem lies: heart and pulmonary vessels, airways, lung and pleura, or outside the chest.

  1. Shortness of breath, new or acutely worse
  2. Look yourself: RR, SpO2, work of breathing, speech, mentation; ABCs, monitor, IV12
  3. ECG, chest X-ray, blood gas, BNP, hs-troponin; lung and cardiac POCUS2,5,12
  4. Respiratory distress?

Distress: call for help; secure the airway12

  • Stridor, angioedema: IM epi10
  • Can't speak; quiet chest
  • Drowsy, tiring, or rising PaCO2
  • Hypoxemia despite high-flow O2
  • Tension PTX signs: decompress
  • Shock: PE, tamponade3,12

→ O2 to SpO2 ≤96% (88–92% if CO2 retainer); intubate early7,8

If not: where is the problem?

CausesCluesWorkupManagement

Heart & vessels

  • Acute heart failure, ACS
  • Pulmonary embolism
  • Arrhythmia, valve disease, tamponade
  • Prior HF (LR 5.8); PND (LR 2.6)2
  • S3 (LR 11); CXR congestion (LR 12)2
  • PE: sudden, pleuritic; clear CXR; DVT3
  • ECG, hs-troponin, (NT-pro)BNP; echo1
  • Diffuse B-lines: edema (sens 97%)5
  • PE: Wells, then D-dimer or CTPA3
  • Edema: CPAP, IV diuretic; nitrate if SBP OK1,6
  • PE: anticoagulate; lyse if shock3
  • ACS: chew ASA; STEMI: cath lab4

Airways

  • Anaphylaxis, angioedema, foreign body
  • Asthma or COPD exacerbation
  • Mucus plug; vocal cord dysfunction
  • Stridor, urticaria after an exposure
  • Wheeze, prolonged expiration
  • A-lines + sliding, no DVT: asthma/COPD5
  • Peak flow or FEV1 if able
  • Blood gas if drowsy or tiring12
  • Spirometry once stable
  • Anaphylaxis: IM epi 0.5 mg, thigh10
  • Nebs, steroids; asthma: IV Mg9,12
  • COPD, pH ≤7.35 + ↑PaCO2: bilevel NIV6,9

Lung & pleura

  • Pneumonia, aspiration
  • Tension pneumothorax
  • Effusion, ARDS, ILD, hemorrhage
  • Fever, cough, focal crackles
  • Unilateral ↓ breath sounds
  • Hypoxemia worse on exertion: ILD12
  • CXR; POCUS: pneumonia sens 89%5
  • No sliding + lung point: PTX5
  • Cultures; tap a new effusion12
  • Tension PTX: needle, then chest tube12
  • Pneumonia: cultures, antibiotics
  • Hypoxemic: HFNC rather than NIV11

Outside the chest

  • Metabolic acidosis: DKA, sepsis
  • Anemia; toxins: CO, salicylate, opioids
  • GBS, MG, ALS; obesity; anxiety
  • Clear lungs; SpO2 normal (falsely in CO)
  • Kussmaul breathing; low HCO3
  • Weak cough, ↓FVC; PaCO2 rises late12
  • VBG, COHb, lactate, glucose, CBC, salicylate
  • Normal A-a, ↑PaCO2: hypoventilation12
  • Bedside FVC or NIF if weak12
  • Opioid: naloxone; treat DKA, sepsis12
  • Weak: serial FVC; ICU early12
  • Anxiety only after the rest excluded12

Can't-miss cause Superscripts link to the references below.

References

  1. Heidenreich PA, Bozkurt B, Aguilar D, et al. 2022 AHA/ACC/HFSA guideline for the management of heart failure. Circulation. 2022;145:e895–e1032. PubMed 35363499
  2. Wang CS, FitzGerald JM, Schulzer M, Mak E, Ayas NT. Does this dyspneic patient in the emergency department have congestive heart failure? JAMA. 2005;294:1944–1956. PubMed 16234501
  3. Writing Committee Members; Creager MA, Barnes GD, Giri J, et al. 2026 AHA/ACC/ACCP/ACEP/CHEST/SCAI/SHM/SIR/SVM/SVN guideline for the evaluation and management of acute pulmonary embolism in adults. Circulation. 2026;153:e977–e1051. PubMed 41712677
  4. Rao SV, O'Donoghue ML, Ruel M, et al. 2025 ACC/AHA/ACEP/NAEMSP/SCAI guideline for the management of patients with acute coronary syndromes. Circulation. 2025;151:e771–e862. PubMed 40014670
  5. Lichtenstein DA, Mezière GA. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest. 2008;134:117–125. PubMed 18403664
  6. Rochwerg B, Brochard L, Elliott MW, et al. Official ERS/ATS clinical practice guidelines: noninvasive ventilation for acute respiratory failure. Eur Respir J. 2017;50:1602426. PubMed 28860265
  7. Siemieniuk RAC, Chu DK, Kim LH, et al. Oxygen therapy for acutely ill medical patients: a clinical practice guideline. BMJ. 2018;363:k4169. PubMed 30355567
  8. O'Driscoll BR, Howard LS, Earis J, Mak V. BTS guideline for oxygen use in adults in healthcare and emergency settings. Thorax. 2017;72(Suppl 1):ii1–ii90. PubMed 28507176
  9. Wedzicha JA, Miravitlles M, Hurst JR, et al. Management of COPD exacerbations: a European Respiratory Society/American Thoracic Society guideline. Eur Respir J. 2017;49:1600791. PubMed 28298398
  10. Cardona V, Ansotegui IJ, Ebisawa M, et al. World Allergy Organization anaphylaxis guidance 2020. World Allergy Organ J. 2020;13:100472. PubMed 33204386
  11. Oczkowski S, Ergan B, Bos L, et al. ERS clinical practice guidelines: high-flow nasal cannula in acute respiratory failure. Eur Respir J. 2022;59:2101574. PubMed 34649974
  12. Gay E, Levy N, eds. Respiratory Distress; Hypoxemia & Hypercapnia; Heart Failure; VTE Diagnostics. In: Department of Medicine Housestaff Manual, 30th ed. 2024:22, 43–44, 51.

For education only; not a substitute for clinical judgment or local protocols. Where sources differ, the flowchart follows the current guideline.

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