Treatment of Pulmonary Edema
Immediately position the patient upright, apply non-invasive positive pressure ventilation (CPAP or NIPPV), administer sublingual nitroglycerin 0.4-0.6 mg, and give furosemide 40 mg IV slowly over 1-2 minutes as the initial treatment approach. 1, 2, 3
Immediate Stabilization and Respiratory Support
Non-invasive ventilation is the cornerstone of initial management and should be applied before considering intubation. Both CPAP and bilevel NIPPV are equally effective, significantly reducing the need for intubation (RR 0.60) and mortality (RR 0.80). 1 These modalities work by improving oxygenation, decreasing left ventricular afterload, and reducing respiratory muscle work. 1 Apply CPAP/NIV in the pre-hospital setting when possible, as this decreases the need for intubation (RR 0.31). 1
Critical caveat: Do not apply CPAP if systolic blood pressure is <90 mmHg. 2
Administer supplemental oxygen only in hypoxemic patients (SpO₂ <90%); avoid routine oxygen in non-hypoxemic patients as it causes vasoconstriction and reduces cardiac output. 1, 2 Position the patient upright or semi-seated immediately to decrease venous return and improve ventilation. 2
Consider endotracheal intubation and invasive ventilation only if worsening hypoxemia, failing respiratory effort, or increasing confusion develops despite non-invasive support. 4
Pharmacological Management: Blood Pressure-Guided Algorithm
Hypertensive Pulmonary Edema (SBP >140 mmHg)
Start with aggressive vasodilator therapy as the primary intervention. 2
Nitroglycerin: Begin with sublingual nitroglycerin 0.4-0.6 mg, repeated every 5-10 minutes up to four times as needed. 1, 2 Transition to intravenous nitroglycerin at 0.3-0.5 μg/kg/min if systolic BP remains adequate. 1 Titrate vasodilators to the highest hemodynamically tolerable dose to achieve optimal vasodilation. 1
Sodium nitroprusside: Use for patients not responsive to nitrate therapy, starting at 0.1 μg/kg/min. 1
Loop diuretics: Administer furosemide 40 mg IV slowly over 1-2 minutes as the initial dose. 2, 3 If satisfactory response does not occur within 1 hour, increase to 80 mg IV slowly over 1-2 minutes. 3 The FDA label specifies this dosing for acute pulmonary edema. 3
Blood pressure target: Aim for an initial rapid reduction of systolic or diastolic BP of 30 mmHg within minutes, followed by more progressive decrease over several hours. 4, 1 Do not attempt to restore normal BP values as this may cause deterioration in organ perfusion. 4
Important warning: Monitor for tolerance to nitrates, which can develop rapidly when given intravenously in high doses. 1
Normotensive Pulmonary Edema (SBP 100-140 mmHg)
Use standard combination therapy: 2
- Nitroglycerin: Same dosing as above (sublingual then IV). 1, 2
- Furosemide: 40 mg IV slowly over 1-2 minutes initially. 2, 3
- Non-invasive ventilation: CPAP or NIPPV as described above. 2
Hypotensive Pulmonary Edema (SBP <100 mmHg)
Avoid nitrates and diuretics in this setting. 2 This presentation suggests imminent or established cardiogenic shock requiring different management. 4 Consider pulmonary artery catheterization to characterize hemodynamic pattern and guide therapy. 4 Inotropic support may be necessary. 4
Adjunctive Pharmacological Therapy
Morphine: Consider in the early stage for patients with severe acute heart failure, particularly when associated with restlessness and dyspnea. 1, 2 However, avoid morphine in respiratory depression or severe acidosis. 2
Diuretic Escalation for Inadequate Response
If urine output is <100 mL/h over 1-2 hours (confirm by bladder catheterization), this represents inadequate initial response. 4 Double the dose of loop diuretic up to equivalent of furosemide 500 mg (doses ≥250 mg should be given by infusion over 4 hours). 4
Consider combining loop and thiazide diuretics for resistant peripheral edema. 1 If no response despite adequate left ventricular filling pressure, start IV dopamine 2.5 μg/kg/min (higher doses not recommended to enhance diuresis). 4 If these steps fail and the patient remains in pulmonary edema, venovenous isolated ultrafiltration should be considered. 4
Advanced Interventions for Refractory Cases
Intra-aortic balloon counterpulsation (IABP): Consider in patients with severe refractory pulmonary edema or those requiring urgent cardiac catheterization and intervention, if no contraindications exist. 4, 1, 2
Pulmonary artery catheterization: Reserve for patients who are refractory to pharmacological treatment, persistently hypotensive, have uncertain LV filling pressure, or are being considered for cardiac surgery. 4 Most patients do not require routine pulmonary artery catheter insertion and stabilize with bedside evaluation. 2
Ventricular assist devices: Consider as "bridge to decision" or longer term in selected patients with persistent heart failure and low systolic blood pressure despite treatment. 4, 2
Concurrent Diagnostic Evaluation
While initiating treatment, rapidly perform: 4, 2
- 12-lead ECG to identify acute myocardial infarction/injury
- Chest radiograph
- Blood tests: cardiac enzymes, electrolytes, BUN, creatinine, CBC
- Arterial blood gases/pulse oximetry
- Transthoracic echocardiography
Management of Specific Etiologies
Acute coronary syndrome: Urgent myocardial reperfusion therapy (cardiac catheterization or thrombolytic therapy) is required for patients with acute myocardial infarction presenting with pulmonary edema. 1
Acute valve incompetence from endocarditis: Surgical consultation should be obtained early, with surgical intervention performed promptly in severe acute aortic or mitral regurgitation. 4
Aortic dissection: Immediate diagnosis and surgical consultation are warranted, with transoesophageal echocardiography as the best technique to assess valve morphology and function. 4
Critical Pitfalls to Avoid
Never use beta-blockers in patients with frank cardiac failure evidenced by pulmonary congestion. 1, 2 This is a critical contraindication.
Avoid aggressive simultaneous use of multiple hypotensive agents, which initiates a cycle of hypoperfusion-ischemia. 1, 2
Do not routinely insert pulmonary artery catheters; reserve for specific indications as outlined above. 2
Monitoring
Monitor heart rate, rhythm, blood pressure, and oxygen saturation continuously for at least the first 24 hours of admission, and frequently thereafter. 4, 1 Assess symptoms relevant to heart failure (dyspnoea, orthopnoea) and treatment-related adverse effects (symptomatic hypotension). 4