Emergency Management of Cardiogenic Pulmonary Edema - The Essentials

Introduction:

Pulmonary edema is a lung disease in which the air-filled sacs in the lungs (alveoli) and the lung spaces get filled with fluid due to various pathological causes. In critical heart problems such as heart failure, the excess pressure in the heart causes excessive fluid accumulation in the lungs' tiny air sacs and spaces. As a result, the carbon dioxide and oxygen exchange that occurs in these air sacs (alveoli) gets affected leading to breathing difficulty.

Due to insufficient gas exchange in the lungs and breathing difficulty, the oxygen levels in the blood go down, damaging the body's vital organs. This life-threatening lung condition due to a heart problem is known as cardiogenic pulmonary edema. This condition is seen in 80 percent of patients with chronic heart diseases and heart failure. These can be acute (sudden severe disease) or chronic (long-standing disease). Cardiogenic pulmonary edema is managed using oxygen supplementation, medications, and special procedures depending on the cause of the cardiogenic pulmonary edema.

What Are the Heart Problems That Cause Pulmonary Edema?

The various causes of cardiogenic pulmonary edema include the following:

1. Congestive heart failure.

2. Heart rhythm problems or arrhythmias.

3. Heart muscle abnormalities and diseases (cardiomyopathy).

4. Heart valve problems, especially on the left side of the heart (the blood regurgitates in the wrong direction in the heart).

5. Heart attack (due to decreased blood flow to the heart and major blood vessel blocks).

What Are the Symptoms Seen in Cardiogenic Pulmonary Edema?

The following symptoms are seen in cardiogenic pulmonary edema:

1. Breathing difficulty (during exertion or at rest).

2. A feeling of suffocation.

3. Shortness of breath that disrupts sleep.

4. Swelling in the lower extremities (in chronic cases).

5. Tiredness.

6. Skin becomes cold and clammy.

7. Noisy breathing sounds.

8. Anxiety and restlessness.

9. Cough.

10. Blood-tinged sputum.

11. Chest pain (when associated with critical illnesses such as heart attack).

12. Increase in the patient's weight by more than two pounds a day (in chronic cases).

What Are the Severe Complications Seen in Cardiogenic Pulmonary Edema?

The underlying cause determines the possible complications in cardiogenic pulmonary edema. The common complications seen include:

1. The risk of irregular heartbeat or function (arrhythmias).

2. Clot formation in the major blood vessels of the heart, lungs, and brain (thromboembolism).

3. Inflammation around the heart (pericarditis).

4. Cardiogenic shock (marked drop in blood pressure).

5. Space around the heart gets filled with fluid and exerts pressure on the heart (cardiac tamponade).

6. Low levels of oxygen in the blood.

7. Damage to the vital organs, including the brain.

8. End-organ damage and multi-organ failure.

9. Death.

How Is Cardiogenic Pulmonary Edema Diagnosed?

The fluid accumulation in the lungs is diagnosed through a thorough physical examination and clinical evaluation of the patient. Severe breathing problems and abnormal breath sounds (pulmonary crackles heard using a stethoscope) indicate pulmonary edema. Other tests to diagnose cardiogenic pulmonary edema include:

• Chest X-ray.

• Pulse oximetry.

• Complete blood count.

• Serum electrolytes (such as sodium and potassium levels)

• Arterial blood gas (carbon dioxide and oxygen levels in the blood)

• To measure serum brain natriuretic peptide levels (BNP).

• Blood tests for special blood proteins known as cardiac markers.

• Electrocardiogram (to check the heart).

• Ultrasonography.

• Echocardiogram (to check the heart valves and muscles).

• Other specific tests to assess the cause of the edema.

• Invasive procedures such as pulmonary artery catheterization, in which a catheter or tube is inserted into the vein and advanced until it reaches the major lung artery (pulmonary artery) to measure the pressure.

How Is Cardiogenic Pulmonary Edema Managed in an Emergency?

Management depends upon the patient's presentation, signs, and symptoms and is tailored from patient to patient. The initial general management of cardiogenic pulmonary edema by the emergency team as the patient arrives includes the following:

• Assessment of the airway (passage to the lungs) is done immediately on first contact with the patient. The airway is made clear to ensure sufficient oxygen-rich air reaches the lungs.

• The breathing is assessed (including the breathing pattern and oxygen saturation).

• The circulation and vital signs (blood pressure, heart rate) are assessed. The heart function is checked and promptly managed to ensure sufficient blood flow and oxygen supply to all body parts and organs. Cardiopulmonary resuscitation is initiated if required.

• Oxygen supplementation is done whenever required. Depending on the patient's condition, there are various ways to provide oxygen to the body. These include:

Bag-Mask Ventilation - Oxygen is pumped through a bag attached to the mask.

Non-invasive Positive Pressure Ventilation (NPPV) - Mild air is blown into the airway using tubes or masks to keep it open.

Ventilator - A machine that helps to support breathing and provides oxygen to the lungs.

Tracheostomy - Oxygen is supplied through a hole (surgically made) in the windpipe.

• Prop up and patient positioning.

• Access into veins (intravenous access) is obtained to give medications if needed.

• The patient’s urine output is monitored.

What Are the Special Treatments Given to Manage Cardiogenic Pulmonary Edema?

After the initial emergency care and resuscitation of the patient’s airway, breathing, and circulation, specific treatment is initiated depending on the cause. These include:

Non-invasive Management:

The two main medications to treat cardiogenic pulmonary edema include diuretics (medications that get more fluids out of the body and vasodilators (medications that help widen the blood vessels). Patients with acute decompensated heart failure with pulmonary edema are treated with intravenous diuretics initially, regardless of the cause. The increased pressure in the left chambers of the heart can be reduced using the following medications:

• Nitroglycerin.

• Isosorbide dinitrate.

• Sodium nitroprusside.

• Loop diuretics (such as Furosemide, Bumetanide, Torsemide).

• Medications used with extreme care include Morphine and Nesiritide.

Bilevel positive airway pressure (BIPAP), a type of ventilator device that helps move the fluid out of the lungs and facilitates breathing, is sometimes used.

Invasive Procedures:

The invasive management of cardiogenic pulmonary edema includes the following:

• Intra-Aortic Balloon Pump (IABP): A balloon is inserted into the major blood vessel of the heart (aorta) to improve blood output and flow.

• Ultrafiltration: A procedure that helps to remove sodium and water more effectively than diuretics.

• Ventricular Assist Devices: These are used in heart failure to improve heart function and blood flow.

• Intubation: Tubes are inserted into the airway to help to breathe and clear the excessive fluids.

• Extracorporeal Membrane Oxygenation (ECMO): Artificial lungs can be used for several days to weeks until the lung recovers.

Other Surgical Procedures Include:

• Cardiac transplant.

• Valve replacement.

• Percutaneous coronary intervention.

• Coronary artery bypass graft.

Conclusion:

Cardiogenic pulmonary edema is a critical illness of the lung and heart that is life-threatening. The lung spaces and air sacs fill up with excess fluid due to increased pressure in the heart. Fluid accumulation in the lungs leads to life-threatening medical emergencies and complications ranging from breathing difficulty to multi-organ failure and death. These health emergencies require prompt medical attention. The goals of managing such patients include initial resuscitation (airway, breathing, circulation) and specific treatment using medications and invasive procedures depending on the cause.