Our lungs work tirelessly to facilitate breathing. When lung function is compromised by an abnormal accumulation of liquid in the air sacs, it leads to a condition known as pulmonary oedema. This life-threatening respiratory disorder makes breathing difficult; however, timely medical treatment can significantly improve patient outcomes, underscoring the importance of early detection of signs and symptoms and awareness about treatment options. In this article, we present crucial information about pulmonary oedema, empowering you to understand the condition and help those around you in emergencies.
What is Pulmonary Oedema?
Pulmonary oedema is the abnormal accumulation of fluid in the lungs, replacing air in the alveoli. It impairs oxygen exchange, hindering essential bodily functions. Individuals with pulmonary oedema experience difficulty in breathing, wheezing, and sometimes a bloody cough. Pulmonary oedema can develop suddenly (acute) or over time (chronic); acute cases are emergencies that need immediate medical attention.
The Difference Between Pulmonary Oedema, Pneumonia, and Pleural Effusion
The fluid buildup in and around the lungs is a common characteristic of pulmonary oedema, pneumonia, and pleural effusion. However, these three conditions differ significantly in how they develop and their underlying causes.
- Pneumonia: Pneumonia is caused by an infection (bacterial, fungal, or viral), whereas the most common cause of pulmonary oedema is congestive heart failure. The nature of the fluid is also different, with the fluid buildup in the pneumonia being thicker than in pulmonary oedema. Pneumonia treatment typically includes oxygen therapy and antibiotics.
- Pleural effusion: Unlike in pulmonary oedema, in pleural effusion, fluids accumulate in abnormal amounts outside the lungs in a lining known as the pleura, located between the chest wall and the lungs, which usually contains some amount of fluids. Pleural effusion is caused by conditions such as pneumonia, cancer, and congestive heart failure. Treatment for pleural effusion includes surgery and procedures to remove fluid.
Pathophysiologic Mechanisms of Pulmonary Oedema
The processes or reasons that lead to the accumulation of fluids in lungs include:
- Increased hydrostatic forces: Increased pressure in the pulmonary blood vessels that leads to pulmonary congestion and the leakage of fluid into the lung tissues.
- Increased microvascular permeability: Inflammation, infection, or injury of pulmonary capillaries that lead to the leakage of fluid into the lung tissues.
- Reduced lymphatic drainage: Impaired flow in the lymphatic system that leads to the accumulation of fluid in the lungs.
Note: Sometimes mixed types of pulmonary oedema may occur, with characteristics of both increased hydrostatic forces and microvascular permeability.
Types and Causes of Pulmonary Oedema
The causes of pulmonary oedema can be broadly divided into two categories:
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Cardiogenic (heart-related)
It refers to the accumulation of fluid in the lungs due to increased pressure in the pulmonary capillary. The most common cause of cardiogenic pulmonary oedema is congestive heart failure, which disrupts the pumping ability of the heart and leads to pulmonary congestion. Common contributing conditions include:
- High blood pressure: Increased pressure in the walls of arteries
- Arrhythmia: An abnormal heart rhythm
- Heart attack: Absence of blood supply to the heart
- Myocarditis: An inflammation of the heart muscles
- Valvular heart disease: Leakage or narrowing of the heart valves
- Cardiomyopathy: Weakening of the heart muscles
- Pericardial effusion: Fluid build-up in the lining around the heart muscles
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Noncardiogenic (non-heart related)
It refers to the fluid accumulation in the alveolar sacs due to reasons other than increased pressure in the pulmonary capillary. Noncardiogenic pulmonary oedema is caused by factors such as:
- Acute Respiratory Distress Syndrome (ARDS): Severe lung inflammation due to infections, trauma, or other triggers, causing capillary leakage and fluid buildup in the lungs.
- Pulmonary embolism: A blood clot that travels from the legs to the lungs and blocks blood flow.
- Trauma to the lungs: Any physical injury that damages or inflames the lungs
- Pneumonia: An infection that leads to fluid buildup in the lungs
- Sepsis: A life-threatening reaction to an infection that leads to tissue damage and organ failure
- Liver disease: A disease that impairs the functioning of the liver
- Adverse reaction to drugs or overdose: A harmful reaction to drugs that damages the lungs
- Kidney failure: A disease that impairs the ability of kidneys to filter out waste
Apart from medical conditions, pulmonary oedema can also be caused by factors such as a rapid ascent in altitude or near drowning situations.
High-Altitude Pulmonary Oedema
High-altitude pulmonary oedema, a severe medical emergency, occurs due to reduced oxygen levels at high altitudes. The pulmonary vessels constrict at high altitudes, leading to leakage of fluid in the lungs. Headache is usually one of the first symptoms, accompanied by rapid heartbeats and shortness of breath.
Swimming-Induced Pulmonary Oedema (SIPE)
Also known as immersion pulmonary oedema, it occurs due to the bursting of lung capillaries during competitive swimming and diving activities. Increased blood pressure from the legs and abdomen damages lung capillaries, leading to pulmonary oedema.
Risk Factors for Pulmonary Oedema
Some of the factors that increase the risk of pulmonary oedema are:
- History of heart diseases, including heart failure
- A history of respiratory conditions, including pneumonia, chronic obstructive pulmonary disorder (COPD), and tuberculosis
- A history of vascular disorders
- Being at high altitudes or rapid ascent to higher altitudes
- Near-drowning incidents
- Trauma or injury to the chest or lungs
- A history of smoking, alcohol, and drug abuse
- Sleep apnea
Signs and Symptoms of Pulmonary Oedema
Seeking medical care as soon as possible is critical in pulmonary oedema cases. Call an ambulance if you or anyone near you experiences the following signs:
Sudden (acute) pulmonary oedema
- Inability to breathe
- Severe chest pain
- Feeling of suffocation
- Skin turning blue
- Profuse sweating accompanied by difficulty breathing
- Cough with frothy and pink mucus
- Irregular heartbeats
- Sudden drop in blood pressure
Long-term (chronic) pulmonary oedema
The signs and symptoms of chronic pulmonary oedema are similar to the acute form of the condition. However, it may be accompanied by other symptoms that appear more frequently, such as:
- Persistent fatigue
- Oedema or swelling in the lower part of the body
- Problems in breathing when lying down
- Rapid weight gain
- New and worsening cough
- Swelling in the legs
- Breathlessness that wakes you up from sleep
Complications of Pulmonary Oedema
Pulmonary oedema, if left untreated, can lead to major complications, such as:
- Breathing difficulties: Severe breathing difficulties, including persistent shortness of breath
- Leg oedema: Leg swelling
- Ascites: A retention of fluid in the abdomen
- Heart failure: Increased pressure on the right side of the heart, leading to its failure
- Enlarged liver: Swelling or congestion in the liver
- Pleural effusion: Fluid build-up in the tissues around the lungs
Immediate medical care for acute pulmonary oedema is crucial to prevent fatality.
Diagnosis of Pulmonary Oedema
Doctors conduct a physical exam to check signs of fluid in the lungs, such as swelling in the body, abnormal sounds from the heart, and an increased rate of respiration. They may further order tests such as:
- Blood tests: Including Complete Blood Counts
- Pulse oximetry: A non-invasive technique to measure blood oxygen saturation
- Chest X-rays: A two-dimensional image of the chest using X-rays
- Chest CT scan: A detailed imaging test that provides cross-sectional views of the chest using X-rays
- Ultrasound of the lungs: Imaging of the chest using sound waves
- Echocardiogram: An ultrasound of the heart
- Electrocardiogram: An analysis of the impulses of the heart to measure the heart rate and the strength of signals
- Cardiac catheterisation: A procedure involving thin tubes to check blockages in the coronary arteries
Treatments for Pulmonary Oedema
The treatment for pulmonary oedema depends on the cause of the condition. Acute pulmonary oedema cases are usually treated in an Intensive Care Unit or an Emergency Room. Treatments and therapies for pulmonary oedema include:
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Oxygen therapy
This is usually the first line of treatment. Oxygen may be delivered through nasal cannulas or masks.
- Diuretics: Medications that help reduce fluid retention by promoting frequent urination.
These are medications given to the patients to induce frequent urination and may be effective in cases of congestive heart failure.
- Vasodilators
These are medications used to dilate blood vessels to reduce the pressure on the heart and improve blood flow to the lungs.
- Medications
Depending on the cause of pulmonary oedema, medications may be prescribed to manage blood pressure, reduce anxiety, or improve heart pumping activity. Ace inhibitors are usually used to relax blood vessels, nitroglycerin to lower the pressure in the heart, beta blockers to regulate blood pressure, and inotropes to strengthen the pumping ability of the heart.
- Mechanical ventilation
In cases of severe pulmonary oedema, mechanical ventilators support breathing and oxygen delivery.
- Lifestyle changes
Individuals at risk of pulmonary oedema are advised to make changes to their lifestyles to prevent future episodes. Recommendations include regular health check-ups, taking medications and fluids as prescribed, maintaining a low-sodium diet, quitting smoking, and getting routine vaccinations.
Conclusion
Pulmonary oedema occurs when fluid accumulates in the lungs, impairing oxygen exchange and causing symptoms like severe breathlessness and chest discomfort. If you or someone near you experiences symptoms of pulmonary oedema, don’t waste time. Call an ambulance and seek treatment immediately. At Graphic Era Hospital, our skilled pulmonologists and emergency doctors provide timely and effective pulmonary oedema treatments, along with compassionate care and support.
Frequently Asked Questions
There are several steps you can take to lower the risk of pulmonary oedema:
- Take medications as prescribed
- Monitor and control cholesterol and blood pressure levels
- Sleep with the upper body in an elevated position
- Engage in 30 minutes of moderate-intensity exercise daily, such as walking or cycling, and incorporate strength training as advised by a doctor
- Get vaccinations on time
- Adopt a healthy diet, low in salt
- Quit smoking
- Maintain your weight in a healthy range
- Consult a doctor if you experience any problems with breathing
