Shortness of Breath

Dyspnea is the subjective sensation of uncomfortable breathing. It can be normal during heavy exercise. Sudden severe dyspnea is always an emergency until proven otherwise.

First priorities: ABCs

1. Airway.
2. Breathing.
3. Circulation.
4. Pulse oximetry.
5. Cardiac monitor.
6. Oxygen as needed.

Always ask: Is this respiratory, cardiac, metabolic, toxicologic, hematologic, or neurologic?

Clinical clues

• Sudden-onset dyspnea.
• Hypoxia.
• Tachycardia.
• Pleuritic chest pain.
• Hemoptysis.
• A normal lung exam is common.

ECG findings

• Sinus tachycardia — most common.
• Right axis deviation.
• Right bundle branch block.
• T-wave inversion in V1–V3.
• S1Q3T3 — classic but uncommon.

Chest X-ray: usually normal.

Diagnosis

• CT pulmonary angiography.
• V/Q scan if contrast is contraindicated.

Treatment

Oxygen, anticoagulation, and thrombolysis for unstable patients.

The handout lists 600 mL of blood as the definition.

Immediate priorities

1. Protect the airway (intubate).
2. Aggressive suctioning.
3. Position the bleeding lung down.
4. Call Interventional Radiology for bronchial artery embolization.

Acute decompensated heart failure / flash pulmonary edema

Classic presentation:

• Sudden nighttime dyspnea (PND).
• Severe hypertension.
• Bilateral rales.
• Wheezing (“cardiac asthma”).
• S3 gallop.
• Pulmonary edema on chest X-ray.

Initial treatment

1. Oxygen.
2. CPAP/BiPAP.
3. Nitroglycerin (first-line).
4. Diuretics if volume overloaded.

BNP

• <100: CHF unlikely.
• 500: CHF likely.

Avoid beta blockers during acute decompensation.

Causes

• Heroin overdose/naloxone.
• ARDS.
• Aspiration.
• Drowning.
• Neurogenic pulmonary edema.
• Inhalation injury.
• Fluid overload.

Treatment

Oxygen, positive-pressure ventilation if needed, and treatment of the underlying cause.

Presentation

Fever, severe tachycardia, atrial fibrillation, hypertension, anxiety, tremor, and altered mental status.

Treatment order

1. Beta blocker (propranolol).
2. PTU or methimazole.
3. Wait 1 hour.
4. Iodine.
5. Steroids.
6. Cooling measures.
7. Treat the precipitating factor.

Moderate to severe treatment

• High-flow oxygen.
• Continuous albuterol.
• Ipratropium (first hour).
• Early systemic steroids.
• Epinephrine/terbutaline if severe.
• Magnesium sulfate as an adjunct for severe attacks.

Intubation indications

• Exhaustion.
• Altered mental status.
• Silent chest.
• Rising CO₂.
• Respiratory arrest.

Ventilator pearls

• Low respiratory rate: 6–12/min.
• Low tidal volume: 6 mL/kg ideal body weight.
• High inspiratory flow.
• Allow prolonged exhalation.
• Permissive hypercapnia is acceptable.

Hypotension after intubation

Think:

• Auto-PEEP (breath stacking).
• Tension pneumothorax.
• Medication effect.

Chronic bronchitis: “blue bloater”

Findings: chronic productive cough, cyanosis, obesity, peripheral edema, and cor pulmonale.

Chest X-ray: increased bronchovascular markings and an enlarged heart.

Emphysema: “pink puffer”

Findings: thin appearance, barrel chest, pursed-lip breathing, hyperinflation, and minimal cough.

Chest X-ray: hyperinflation, bullae, and a small heart.

ABG interpretation

The handout favors ABG over VBG in severe COPD. Look for hypoxemia, hypercapnia, and acidosis.

Top exam pearls

• ABCs always come first.
• Oxygen is appropriate for almost every unstable dyspneic patient.
• PE often has a normal chest X-ray.
• S3 is the most specific physical finding for CHF.
• Pulmonary edema is the most specific chest X-ray finding for CHF.
• BNP <100 essentially excludes CHF.
• Nitroglycerin is first-line for hypertensive pulmonary edema.
• CPAP/BiPAP reduces intubation in CHF.
• Silent lungs in asthma = impending arrest.
• Auto-PEEP is a common cause of hypotension after intubating severe asthma.
• Thyroid storm treatment sequence: beta blocker → PTU/methimazole → wait 1 hour → iodine → steroids.