Dyspnea
ABCs
- check vitals + cardiac monitor; if desaturation → 15 L NRB
- target SpO₂
- 94–98% (most patients)
- 88 to 92% if COPD / CO₂ retention
- if unsure → aim ~92% + send urgent VBG
red flags
don’t miss
- dyspnea at rest or rapidly worsening
- chest pain (especially sudden / severe)
- diaphoresis or syncope
- hypoxia / cyanosis
- hypotension or shock
- stridor → airway compromise
- unequal breath sounds → pneumothorax / collapse
- silent chest → severe asthma
- pulsus paradoxus / distant heart sounds → tamponade
- BP difference > 20 mmHg → aortic dissection
- reduced consciousness / agitation
HPI & examination
- key history
- onset and progression (acute vs gradual)
- overload symptoms → orthopnea, PND, LL edema
- chest pain, diaphoresis, nausea (cardiac)
- fever, cough, sick contact (infectious)
- VTE risk → prior VTE, immobility, OCPs
- lung disease (asthma, COPD, ILD); cardiac history (IHD, heart failure); renal / dialysis
- medications → diuretics, inhalers
- examination
- general: distress, work of breathing
- respiratory: air entry, wheeze, crackles, stridor
- cardiac: heart sounds, murmurs
- peripheral: edema, signs of DVT; neuro: mental status
initial, for all
- oxygen → target saturation
- ABG / VBG + CXR ± BNP
- ECG + troponin ± D-dimer (if chest pain)
differentials
- Upper airway obstruction: stridor, angioedema, anaphylaxis
- call for help immediately
- airway support → Anesthesia / ENT
- Pneumothorax: sudden dyspnea, ↓ breath sounds
- urgent CXR
- needle decompression if tension
- surgical consult
- Severe asthma: silent chest, drowsy, ↑ CO₂
- call for help + ICU review
- Aortic dissection (unstable): shock, severe pain
- call for help
- TEE / POCUS
- cardiothoracic consult
- hemodynamic support
- Pulmonary embolism: SOB, tachycardia, DVT risk
- CTPA if stable
- if delayed start anticoagulation (enoxaparin 1 mg/kg SC q12h)
- bedside echo if unstable
- Pulmonary edema: orthopnea, PND, edema, ↑ BNP
- IV furosemide 40–80 mg if BP stable
- O₂ ± NIV
- add GTN (SL or infusion) if hypertensive / not hypotensive
- Aortic dissection (stable): tearing pain, BP difference
- CTA
- control SBP 100–120
- HR ≤ 60
- β-blocker
- Lung collapse: unequal / absent breath sounds
- urgent CXR
- respiratory consult
- Pneumonia / HAP: fever, cough
- CXR + labs (CRP, PCT, RFT, LFT)
- empiric antibiotics after senior input, CAP: ceftriaxone 1–2 g IV q24h + azithromycin 500 mg (or clarithromycin 500 mg BD)
- or levofloxacin 750 mg
- HAP: pip-tazo 4.5 g IV q6h ± vancomycin if MRSA risk
- Asthma exacerbation: wheeze, SOB
- O₂ (15 L NRB)
- Salbutamol 5 mg neb q20 min (continuous if severe) + Ipratropium 0.5 mg q20 min + IV Methylprednisolone 40–60 mg
- magnesium sulfate 2 g IV if life-threatening
- reassess after 1 hr
- COPD exacerbation: known COPD, ↑ sputum / purulence
- salbutamol 5 mg + ipratropium 0.5 mg neb
- prednisolone 30–40 mg PO ×5 d (or hydrocortisone 100 mg IV)
- antibiotic if infective
- NIV if pH < 7.35 / hypercapnic
- controlled O₂ 88–92%
calculator Wells’ criteria (PE) · MDCalc ↗︎
furosemide notes (high yield)
- PO furosemide ≈ ½ IV dose
- Lasix-naïve → start 20–40 mg IV
- on Lasix → give 1–2.5× daily oral dose (IV)
- if no response → double the dose
- max single dose 80–200 mg; max daily 600 mg
- higher doses may be needed in renal disease
see also, MOC+ Volume 2: Cardiopulmonary covers acute heart failure, PE, and asthma / COPD exacerbations in depth. browse the library.
studying for the IM exam? the IM Rapid Review covers the breathless patient in the same format. see the sample chapter.
Last reviewed · June 2026