One-liner#

Evaluate acute dyspnea (hours to days) to rapidly identify life-threatening causes (PE, ACS, pneumothorax, severe asthma/COPD) requiring emergent management while triaging patients who can be safely managed in the outpatient setting.

Quick nav#

• Red flags / send to ED
• Key history
• Focused exam
• Differential (quick pattern recognition)
• Workup
• Initial management
• Management by diagnosis
• Follow-up
• Patient instructions
• Smartphrase snippets

Red flags / send to ED#

• SpO₂ <92% on room air (or significant drop from patient’s baseline)
• Respiratory rate >24 with distress
• Accessory muscle use, tripod positioning, nasal flaring
• Inability to speak in full sentences
• Altered mental status
• Hypotension (SBP <90) or signs of shock
• Chest pain concerning for ACS
• Suspected PE with hemodynamic instability
• Stridor or signs of upper airway obstruction
• Severe asthma/COPD exacerbation not responding to initial bronchodilator
• Suspected anaphylaxis
• New arrhythmia with hemodynamic compromise

Key history#

Onset and timeline:

• Sudden (seconds to minutes): PE, pneumothorax, arrhythmia, anaphylaxis, foreign body
• Rapid (hours): asthma/COPD exacerbation, pneumonia, HF exacerbation, anxiety
• Subacute (days): pneumonia, HF, pleural effusion

Character of dyspnea:

• “Can’t get enough air” / air hunger: PE, metabolic acidosis, anemia
• “Chest tightness”: asthma, ACS, anxiety
• “Heavy breathing” / work of breathing: COPD, pneumonia, HF
• Positional: orthopnea/PND (HF), platypnea (hepatopulmonary syndrome, ASD)

Associated symptoms:

• Chest pain: PE (pleuritic), ACS (pressure), pneumothorax (sudden, pleuritic), pneumonia (pleuritic)
• Cough: pneumonia, asthma, HF (pink frothy = pulmonary edema)
• Fever: pneumonia, sepsis
• Leg swelling/pain: DVT → PE
• Palpitations: arrhythmia, PE, anxiety
• Wheezing: asthma, COPD, cardiac asthma (HF)
• Hemoptysis: PE, pneumonia

Risk factors to assess:

PE risk factors:

• Recent surgery or immobilization (>3 days)
• Active malignancy
• Prior VTE
• Pregnancy/postpartum
• Estrogen use (OCP, HRT)
• Long travel (>4 hours)
• Obesity
• Thrombophilia

Cardiac risk factors:

• Known CAD, HF, arrhythmia
• HTN, DM, hyperlipidemia, smoking
• Family history of premature CAD

Medication and substance review:

• Beta-blockers: may mask tachycardia; can trigger bronchospasm
• NSAIDs: fluid retention, HF exacerbation
• New medications: drug-induced lung disease, anaphylaxis
• Illicit drugs: cocaine (ACS, pneumothorax), opioids (respiratory depression)

Psychosocial:

• Anxiety/panic history: but this is a diagnosis of exclusion
• Recent stressors: may trigger panic but don’t assume

Focused exam#

• Vitals: SpO₂ (most important), RR, HR, BP, temperature
• General: respiratory distress (accessory muscle use, tripod, nasal flaring, diaphoresis), ability to speak in full sentences, mental status
• HEENT: JVD (HF, PE, tamponade), stridor (upper airway obstruction)
• Lungs:
  • Wheezes: asthma, COPD, cardiac asthma
  • Crackles: pneumonia (focal), HF (bilateral, bases), ILD
  • Decreased breath sounds: pleural effusion, pneumothorax, COPD
  • Absent breath sounds unilaterally: pneumothorax
• Cardiac: tachycardia, irregular rhythm, S3 (HF), loud P2 (pulmonary HTN), murmurs
• Extremities: unilateral leg swelling/tenderness (DVT), bilateral edema (HF), cyanosis
• Skin: urticaria, angioedema (anaphylaxis), pallor (anemia)

Quick severity assessment:

• Can speak in full sentences → less severe
• Speaking in phrases → moderate
• Speaking in words only → severe
• Unable to speak → critical

Differential (quick pattern recognition)#

Common/likely (outpatient)#

Can’t-miss / urgent#

Workup#

Immediate assessment (all patients):

• SpO₂ on room air
• Respiratory rate
• Ability to speak in full sentences
• ECG if any cardiac concern

Decision: Can this patient be worked up in the office?

Send to ED if:

• SpO₂ <92% (or significant drop from baseline)
• Respiratory distress (accessory muscles, can’t speak in sentences)
• Hemodynamic instability
• High suspicion for PE, ACS, pneumothorax, anaphylaxis
• Severe asthma/COPD not responding to initial treatment
• Uncertain diagnosis with concerning presentation

Can evaluate in office if:

• SpO₂ ≥94% on room air
• Able to speak in full sentences
• Hemodynamically stable
• Clear diagnosis (e.g., mild asthma exacerbation, anxiety)

Office workup:

PE evaluation (Wells criteria):

• ≤4 points (PE unlikely): D-dimer; if negative, PE ruled out
• >4 points (PE likely): CT-PA (skip D-dimer); send to ED if unstable

PERC rule (use BEFORE Wells if PE not your leading diagnosis): If ALL of the following are true, PE is effectively ruled out without D-dimer:

• Age <50
• HR <100
• SpO₂ ≥95%
• No hemoptysis
• No estrogen use
• No prior DVT/PE
• No unilateral leg swelling
• No surgery/trauma requiring hospitalization in past 4 weeks

If any PERC criterion is positive → proceed to Wells score

Age-adjusted D-dimer:

• For patients >50 years: use cutoff of (age × 10) ng/mL instead of 500 ng/mL
• Example: 70-year-old → D-dimer <700 ng/mL rules out PE
• Reduces false positives in elderly without missing PE

Patients with baseline hypoxia (e.g., COPD on home O₂):

• Compare to patient’s known baseline SpO₂
• Drop of ≥3–4% from baseline is significant even if absolute SpO₂ >92%
• Lower threshold for ED referral in these patients

When NOT to order:

• D-dimer in high-probability PE (will be positive; need CT-PA)
• D-dimer in low-risk patient with clear alternative diagnosis
• Troponin in office (if concerned enough to check, send to ED)
• ABG in office (rarely changes management; pulse ox sufficient)

Initial management#

Immediate stabilization:

1. Supplemental O₂ if SpO₂ <92% (nasal cannula 2–4 L/min)
2. Position of comfort (usually sitting upright)
3. Continuous pulse oximetry monitoring
4. IV access if available and patient unstable

Condition-specific initial treatment:

Asthma/COPD exacerbation:

• Albuterol nebulizer 2.5 mg or MDI 4–8 puffs via spacer
• Ipratropium nebulizer 0.5 mg (add to albuterol)
• Prednisone 40–60 mg PO (or methylprednisolone if unable to take PO)
• Reassess in 20–30 minutes; repeat bronchodilators if needed

Suspected PE:

• If hemodynamically stable and low-moderate probability: D-dimer in office
• If high probability or unstable: send to ED for CT-PA
• Do NOT delay transfer for testing if high suspicion

Suspected ACS:

• Aspirin 325 mg chewed (if no contraindication)
• ECG immediately
• Send to ED; do not attempt to rule out ACS in office

Suspected anaphylaxis:

• Epinephrine 0.3–0.5 mg IM (1:1000) in anterolateral thigh
• Call 911
• Repeat epinephrine in 5–15 minutes if no improvement
• H1 blocker (diphenhydramine 50 mg) and H2 blocker (famotidine 20 mg)

Anxiety/panic (diagnosis of exclusion):

• Reassurance and coaching (slow breathing)
• Only diagnose after ruling out organic causes
• Do not give benzodiazepines until organic causes excluded

Management by diagnosis#

Asthma Exacerbation#

Education:

• Acute worsening triggered by infection, allergens, irritants, or medication non-adherence
• Early treatment prevents progression to severe exacerbation
• Review and update asthma action plan

Treatment:

Mild-moderate (speaking in sentences/phrases, SpO₂ >90%):

Severe (speaking in words, SpO₂ <90%, accessory muscles):

• Send to ED
• While awaiting transport: continuous albuterol, ipratropium, steroids, O₂

Follow-up: Reassess in 1–2 days if moderate. Review maintenance therapy; step up if needed. Ensure asthma action plan.

COPD Exacerbation#

Education:

• Acute worsening beyond day-to-day variation
• Usually triggered by infection (viral > bacterial) or environmental factors
• Defined by increased dyspnea, sputum volume, and/or sputum purulence

Treatment:

Antibiotic indications:

• All 3 cardinal symptoms (increased dyspnea + sputum volume + purulence)
• 2 symptoms if one is increased purulence
• Severe exacerbation

Follow-up: Reassess in 48–72 hours. If not improving, consider CXR, hospitalization. Review maintenance therapy after recovery.

Community-Acquired Pneumonia#

Education:

• Bacterial lung infection requiring antibiotics
• Most outpatients recover with oral antibiotics
• Cough and fatigue may persist weeks after treatment

Treatment:

Outpatient (no comorbidities):

Outpatient (with comorbidities):

Follow-up: Reassess 48–72 hours if not improving. CXR at 6–8 weeks for smokers/age >50.

Heart Failure Exacerbation#

Education:

• Fluid overload from dietary indiscretion, medication non-adherence, or disease progression
• Daily weights help detect early fluid retention
• Sodium and fluid restriction important

Treatment:

Mild-moderate (can manage outpatient if close follow-up available):

Adjunctive measures:

• Sodium restriction (<2 g/day)
• Fluid restriction (1.5–2 L/day) if hyponatremic
• Daily weights (call if gain >2–3 lbs in 1–2 days)
• Ensure on optimal GDMT (ACEi/ARB/ARNI, beta-blocker, MRA, SGLT2i)

Send to ED if:

• SpO₂ <92%
• Severe dyspnea at rest
• Hypotension
• New arrhythmia
• Unable to take oral medications
• Inadequate home support for close monitoring

Follow-up: Reassess in 1–3 days with weight, symptoms, renal function. Cardiology follow-up within 1–2 weeks.

Pulmonary Embolism#

Recognition in office:

• Sudden dyspnea + pleuritic chest pain + PE risk factors
• Tachycardia, tachypnea, hypoxia out of proportion to exam
• Unilateral leg swelling (DVT)

PCP role:

• Calculate Wells score
• If PE unlikely (Wells ≤4): D-dimer; if negative, PE ruled out
• If PE likely (Wells >4) or D-dimer positive: send to ED for CT-PA
• If hemodynamically unstable: call 911

Do NOT:

• Start anticoagulation in office before confirming diagnosis (unless very high suspicion and delay to imaging)
• Attempt to manage confirmed PE as outpatient without hematology/pulmonology guidance

Follow-up: After ED evaluation and anticoagulation initiation, PCP manages long-term anticoagulation (typically 3+ months).

Anxiety/Panic Attack#

Education:

• Diagnosis of EXCLUSION—must rule out organic causes first
• Symptoms are real and distressing but not dangerous
• Hyperventilation causes tingling, lightheadedness, chest tightness

Treatment:

Acute episode (after ruling out organic cause):

• Reassurance
• Slow breathing techniques (breathe in 4 sec, hold 4 sec, out 4 sec)
• Remove from triggering environment if possible

If recurrent panic attacks:

Follow-up: Mental health referral for CBT (most effective for panic disorder). Reassess SSRI efficacy in 4–6 weeks.

Pneumothorax#

Recognition in office:

• Sudden onset dyspnea + pleuritic chest pain
• Risk factors: tall/thin young male, smoking, COPD, trauma, recent procedure
• Decreased breath sounds unilaterally; hyperresonance

PCP role:

• If suspected: CXR to confirm
• Small primary spontaneous pneumothorax (<2 cm) in stable patient: may observe with repeat CXR in 3–6 hours
• Large pneumothorax or any secondary pneumothorax (underlying lung disease): ED for chest tube
• Tension pneumothorax (tracheal deviation, hypotension): call 911; needle decompression if trained

Follow-up: After resolution, counsel on smoking cessation, avoid air travel and scuba diving until cleared.

Follow-up#

Default intervals:

• Asthma/COPD exacerbation: reassess in 1–2 days; follow-up in 2–4 weeks to review maintenance
• Pneumonia: phone check at 48–72 hours; CXR at 6–8 weeks if smoker/age >50
• HF exacerbation: reassess in 1–3 days; cardiology within 1–2 weeks
• Anxiety/panic: follow-up in 1–2 weeks; mental health referral

Return precautions (all patients):

• Worsening shortness of breath
• New or worsening chest pain
• Fever (if not already present)
• Coughing up blood
• Swelling in one leg
• Feeling faint or passing out
• Unable to speak in full sentences

Patient instructions#

• Shortness of breath can have many causes, some serious. We are working to find the cause and treat it.
• If your breathing gets worse, you develop chest pain, or you feel like you might pass out, call 911 or go to the emergency room immediately.
• Take all medications exactly as prescribed. If you have an inhaler, use it as directed.
• If you smoke, quitting is one of the most important things you can do for your breathing.
• Weigh yourself daily if you have heart failure. Call the office if you gain more than 2–3 pounds in 1–2 days.
• Keep your follow-up appointment so we can make sure you are improving.

Smartphrase snippets#

.DYSPNEAACUTEASTHMA Acute asthma exacerbation, [mild/moderate] severity. SpO₂ [X]% on room air. Treated with albuterol nebulizer x [#] and started prednisone 40 mg daily x 5 days. Symptoms improved. Discharged home with albuterol PRN and prednisone. Reviewed asthma action plan and return precautions. Follow-up in [1–2 days / 2 weeks].

.DYSPNEAACUTECOPD COPD exacerbation with [increased dyspnea/sputum/purulence]. SpO₂ [X]% on room air. Started prednisone 40 mg daily x 5 days and [azithromycin/doxycycline] given purulent sputum. Increased bronchodilator frequency. Discussed return precautions. Reassess in 48–72 hours.

.DYSPNEAACUTEED Acute dyspnea with [concerning features: hypoxia/respiratory distress/suspected PE/ACS]. SpO₂ [X]%. Referred to ED for [further evaluation/CT-PA/troponin/admission]. [Gave aspirin 325 mg / Started O₂ / Gave albuterol] prior to transfer.

Related pages#

• Dyspnea (Chronic) — evaluation of chronic shortness of breath
• Cough (Acute) — acute cough differential including pneumonia
• Wheeze — wheezing-focused evaluation
• Chest Pain — chest pain differential including ACS and PE
• Palpitations — arrhythmia evaluation
• Asthma (problem) — chronic asthma management
• COPD (problem) — chronic COPD management
• Heart Failure (problem) — chronic HF management
• Atrial Fibrillation (problem) — AF management when arrhythmia causes dyspnea