Pulmonary Edema: Fluid in Lungs Causes, Symptoms, and Treatment Options

Pulmonary edema is abnormal accumulation of fluid in the alveoli and interstitial spaces of the lungs, impairing gas exchange and causing respiratory distress.

Major Causes

Cardiogenic (Heart Failure)

• Left ventricular failure → ↑ pulmonary venous pressure → transudation into alveoli.
• Acute decompensated HF, acute MI, severe aortic/mitral valve disease, arrhythmias.

Non-Cardiogenic

• ARDS: Sepsis, pneumonia, trauma, aspiration, pancreatitis — inflammatory alveolar-capillary leak.
• High altitude (HAPE): Hypoxic pulmonary vasoconstriction → capillary stress failure.
• Neurogenic: Head trauma, seizures, intracranial hemorrhage — sympathetic surge.
• Renal failure: Volume overload, uremic inflammation.
• Drugs/toxins: Heroin, aspirin, chemotherapy, amiodarone.
• Transfusion-related (TRALI): Antibody-mediated.

Symptoms

• Acute dyspnea (often orthopnea, paroxysmal nocturnal dyspnea)
• Cough — frothy, pink-tinged sputum (classic)
• Wheezing ("cardiac asthma")
• Tachycardia, hypertension (initially), diaphoresis
• Hypoxemia, respiratory alkalosis → metabolic acidosis
• Peripheral edema, elevated JVP (if cardiogenic)

Diagnosis

• CXR: Bilateral alveolar infiltrates ("batwing"), Kerley B lines, cephalization, cardiomegaly, pleural effusions.
• BNP/NT-proBNP: Elevated in cardiogenic; helps differentiate.
• Echo: LV function, valvular assessment.
• ABG: Hypoxemia, A-a gradient.

Treatment

Immediate

• Oxygen (target SpO₂ >90%); high-flow nasal cannula, NIV (BiPAP), or intubation.
• IV loop diuretics (furosemide) for cardiogenic — mainstay.
• Vasodilators (nitroglycerin, nitroprusside) to reduce preload/afterload.
• Inotropes (dobutamine) if low output.

Non-Cardiogenic

• Treat underlying cause (antibiotics for sepsis, etc.).
• Lung-protective ventilation (low tidal volume, PEEP).
• Fluid conservative strategy.

Adjuncts

• Morphine (reduces anxiety, preload) — used cautiously.
• ACE inhibitors/ARBs, beta-blockers, MRAs for chronic HF management.

Rapid recognition and treatment are lifesaving; identify and address the underlying etiology.