How to manage acute pulmonary edema?

Management of Flash Pulmonary Edema

High-dose intravenous nitroglycerin combined with low-dose furosemide is the optimal first-line treatment for flash pulmonary edema, prioritizing aggressive vasodilation over aggressive diuresis. 1, 2

Immediate Stabilization

• Position the patient semi-upright to improve ventilation and reduce venous return 1
• Administer supplemental oxygen immediately to maintain SpO2 >90% 1
• Establish continuous monitoring of ECG, blood pressure, heart rate, and oxygen saturation 1
• Obtain intravenous access for medication administration 1

Primary Pharmacological Strategy

Nitroglycerin (First-Line)

• Begin with sublingual nitroglycerin 0.4-0.6 mg, repeated every 5-10 minutes up to four times as needed 3, 2
• Immediately initiate IV nitroglycerin at 0.3-0.5 μg/kg/min if systolic blood pressure remains ≥95-100 mmHg 4, 1, 3
• Titrate nitroglycerin aggressively to the highest hemodynamically tolerable dose while maintaining systolic blood pressure >85 mmHg 1, 3
• Higher initial doses (≥100 μg/min) achieve blood pressure targets faster than low doses (<100 μg/min), with 57% reaching targets within one hour versus 22% with low doses 5

Furosemide (Adjunctive, Low-Dose)

• Administer furosemide 20-40 mg IV as a slow bolus (over 1-2 minutes) shortly after diagnosis 4, 2, 6
• Never use furosemide as monotherapy in moderate-to-severe pulmonary edema—it must be combined with high-dose nitrates 2
• If inadequate response within 1 hour, increase to 80 mg IV 2, 6
• For patients already on chronic oral diuretics, use a bolus dose at least equivalent to their oral dose 2
• Avoid aggressive diuresis as furosemide transiently worsens hemodynamics for 1-2 hours (increases systemic vascular resistance, increases left ventricular filling pressures, decreases stroke volume) 2

Alternative Vasodilator

• Consider sodium nitroprusside (starting dose 0.1 μg/kg/min) for patients not immediately responsive to nitrate therapy or when pulmonary edema is due to severe mitral/aortic regurgitation or marked systemic hypertension 4
• Titrate to improve clinical and hemodynamic status, using systolic pressure of 85-90 mmHg as the usual lower limit 4

Morphine Sulfate

• Administer morphine 3-5 mg IV to reduce anxiety, decrease preload, and improve dyspnea 4, 1
• Avoid morphine in patients with chronic pulmonary insufficiency, respiratory depression, or metabolic/respiratory acidosis 4, 1

Respiratory Support

Non-Invasive Positive Pressure Ventilation (First-Line)

• Apply CPAP or bilevel NIV immediately as the primary intervention before considering intubation in patients with respiratory distress (respiratory rate >25 breaths/min, SpO2 <90% despite conventional oxygen) 1, 3, 2
• Both CPAP and bilevel NIV reduce intubation rates (RR 0.60) and mortality (RR 0.80) 3
• CPAP in the prehospital setting decreases need for intubation (RR 0.31) 3, 7
• Typical settings: CPAP at 10 cmH2O or bilevel with EPAP 5 cmH2O and inspiratory pressure 12-25 cmH2O 8
• Do not apply CPAP in patients with hypotension (systolic blood pressure <90 mmHg) 1

Intubation and Mechanical Ventilation

• Proceed to intubation if persistent hypoxemia, hypercapnia with acidosis, deteriorating mental status, or hemodynamic instability despite interventions 1, 3
• Intubation is indicated for severe hypoxia not responding rapidly to therapy and respiratory acidosis 4

Management of Refractory Cases

• Consider dopamine infusion at 2.5 μg/kg/min if inadequate diuresis persists despite optimized therapy (higher doses not recommended for enhancing diuresis) 1
• Consider venovenous isolated ultrafiltration if pulmonary edema persists despite diuretic therapy and dopamine 1
• Intraaortic balloon counterpulsation may benefit patients with severe refractory pulmonary edema, particularly if urgent cardiac catheterization is planned 4, 1
• Avoid intraaortic balloon counterpulsation in patients with significant aortic valvular insufficiency or aortic dissection 4, 1
• Consider ventricular assist devices or other mechanical circulatory support in selected patients 1

Identify and Treat Underlying Cause

Acute Myocardial Infarction

• Consider urgent myocardial reperfusion therapy (cardiac catheterization with angioplasty or thrombolytic therapy) if acute myocardial infarction is present 4, 1, 3

Valvular Causes

• Consider definitive surgical correction when clinically feasible for acute mitral or aortic regurgitation 1
• Rare patients with severe refractory pulmonary edema and correctable lesions (e.g., ruptured papillary muscle with acute mitral regurgitation) may need to proceed directly to surgery after prompt diagnosis by clinical examination and echocardiography 4

Hypertensive Crisis

• Aim for initial rapid reduction of systolic or diastolic blood pressure by 30 mmHg, then gradually decrease to pre-crisis values 1
• Avoid excessive rapid reduction of blood pressure as it may compromise organ perfusion 1

Monitoring Parameters

• Monitor heart rate, rhythm, blood pressure, and oxygen saturation continuously for at least 24 hours 1
• Assess respiratory rate, use of accessory muscles, and symptoms relevant to heart failure daily 1
• Monitor fluid intake and output 1
• Assess renal function closely as worsening creatinine correlates with increased long-term mortality 2

Hemodynamic Monitoring

• Consider pulmonary artery catheter placement if: (1) clinical course is deteriorating; (2) recovery not proceeding as expected; (3) high-dose nitroglycerin or nitroprusside required; (4) dobutamine or dopamine needed; or (5) diagnostic uncertainty exists 4, 3