Pulmonary Edema, Acute

KEY FINDINGS

• Acute onset or worsening of dyspnea at rest

• Tachycardia, diaphoresis, cyanosis

• Pulmonary rales, rhonchi, expiratory wheezes

• Chest radiograph shows interstitial and alveolar edema with or without cardiomegaly

• Arterial hypoxemia

• Cardiac causes include

  • Acute myocardial infarction (MI) or ischemia

  • Acute severe hypertension

  • Acute kidney injury

  • Heart failure (HF)

  • Valvular regurgitation

  • Mitral stenosis

• Noncardiac causes include

  • Intravenous opioids

  • Increased intracerebral pressure

  • High altitude

  • Sepsis

  • Medications

  • Inhaled toxins

  • Transfusion reactions

  • Shock

  • Disseminated intravascular coagulation

Clinical Findings

• Severe dyspnea

• Pink, frothy sputum

• Diaphoresis

• Cyanosis

• Rales, wheezing, or rhonchi in all lung fields

• Sudden onset in acute exacerbations of HF or acute MI

Diagnosis

• Characteristic clinical findings

• Chest radiograph

  • Pulmonary vascular congestion

  • Increased interstitial markings

  • Butterfly pattern of alveolar edema

  • Heart enlarged or normal in size

• Echocardiography: assesses ejection fraction, atrial pressure

• B-type natriuretic peptide (BNP) is elevated

• Pulmonary capillary wedge pressure

  • Always elevated (usually > 25 mm Hg) in cardiogenic pulmonary edema

  • Normal or even low in noncardiogenic pulmonary edema

Treatment

• Place patient in a sitting position with legs dangling over the side of the bed

• Give oxygen by mask for PaO₂ < 60 mm Hg

• Noninvasive pressure support ventilation or endotracheal intubation and mechanical ventilation for respiratory distress

• Morphine, 4–8 mg intravenously or subcutaneously, repeated as needed after 2–4 hours (avoid in patients with opioid-induced and neurogenic pulmonary edema)

• Diuretic (furosemide, 40 mg intravenously, or bumetanide, 1 mg intravenously—or higher doses if the patient has been receiving long-term diuretic therapy)

• Nitroglycerin sublingually, orally, or intravenously

• Inhaled β-adrenergic agonists or intravenous aminophylline for bronchospasm

• Intravenous nesiritide

  • Reserved for patients who continue to be symptomatic after initial treatment with diuretics and nitrates

  • Hemodynamic effects resemble those of intravenous nitroglycerin with a more predictable dose–response curve and a longer duration of action

  • Dosage: 2 mcg/kg by intravenous bolus injection followed by an infusion of 0.01 mcg/kg/min, which may be uptitrated if needed

  • Primary adverse effect is hypotension, which may be symptomatic and sustained

• Positive inotropic agents

  • Reserved for patients with refractory symptoms and signs of low cardiac output, particularly if life-threatening vital organ hypoperfusion, such as deteriorating kidney function, is present

  • In some cases, dobutamine or milrinone may help maintain patients who are awaiting cardiac transplantation