What Happens When Lung Tissue Swells from Overinflation

What Happens When Lung Tissue Swells Due to Overinflation

The lungs are incredibly elastic organs that continuously expand and recoil with each breath. But sometimes, they can become overinflated, causing the delicate lung tissue to swell. This condition is known as pulmonary distention.

Pulmonary distention occurs when the alveoli (small air sacs) in the lungs expand beyond their normal capacity. This overstretching damages the walls of the alveoli and surrounding blood vessels. It can be an extremely dangerous situation.

Understanding the causes, symptoms, risk factors, and treatments for lung tissue swelling due to overinflation can help you identify and properly manage this condition.

What Causes Pulmonary Distention?

There are several possible causes of lung overinflation leading to tissue swelling:

• Mechanical ventilation: The use of a mechanical ventilator is the most common cause of pulmonary distention. The pressure from the ventilator can overinflate the lungs.
• Chest trauma: Blunt force or penetrating trauma to the chest can lead to lung collapse. Overinflation may occur when re-expanding the lung.
• Anesthesia complications: Some anesthesia-related errors involving misuse of ventilation can excessively inflate the lungs.
• Asthma attack: Severe asthma exacerbations occasionally cause distention injury when struggling to breathe.
• Airway obstruction: Blockages due to foreign objects, mucus plugs, or tumors can trap air and hyperinflate the lungs when coughing forcefully.

Mechanical Ventilation and Pulmonary Distention

The use of mechanical ventilation increases the risk of lung overinflation and swelling. Ventilators are life-saving medical devices. But improper settings or inadequate monitoring can lead to ventilator-induced lung injury (VILI).

With mechanical ventilation, high inspiratory pressures and large tidal volumes are the main culprits for pulmonary distention. This causes excessive stretching and tearing of lung tissue.

Strategies to avoid VILI include limiting tidal volume size, monitoring plateau pressures, allowing the expiratory phase to fully complete, and implementing recruitment maneuvers cautiously.

Symptoms of Pulmonary Distention

The major symptoms associated with lung overinflation and tissue swelling include:

• Shortness of breath
• Difficulty breathing
• Wheezing or gasping respirations
• Chest tightness or discomfort
• Rapid, shallow breathing
• Reduced oxygen saturation levels

In severe cases, pulmonary distention can lead to critical respiratory failure requiring urgent medical intervention.

Risk Factors for Pulmonary Distention

Certain medical conditions and situations raise the risks for lung overinflation and swelling. These include:

• Acute respiratory distress syndrome (ARDS): ARDS involves severe inflammation and fluid accumulation in the lungs that requires mechanical ventilation. The damaged ARDS lung is at very high risk for distention injury.
• Chronic obstructive pulmonary disease (COPD): The enlarged, hyperinflated lungs in COPD are vulnerable to barotrauma from mechanical ventilation.
• Asthma: Poorly controlled asthma with severe attacks can lead to air trapping and pulmonary distention.
• Smoking: Chronic smokers have increased risk due to lung tissue damage.
• Old age: Elderly patients have less lung elasticity and often require mechanical ventilation.
• Obesity: Excess weight presses on chest and can increase difficulty breathing.

Diagnosing Pulmonary Distention

Pulmonary distention is challenging to diagnose conclusively. But doctors utilize several strategies to identify overinflated, swollen lung tissue:

• Listening to chest with stethoscope for abnormal breath sounds like wheezing or crackles.
• Obtaining blood gases to evaluate oxygen and carbon dioxide levels.
• Imaging tests like x-rays, CT scans, and ultrasounds to visualize lung inflation.
• Monitoring airway pressures during mechanical ventilation for high plateau pressures.
• Evaluating patient response to recruitment maneuvers and other ventilator adjustments.

Putting together symptoms, risk factors, and test results helps identify pulmonary distention requiring prompt treatment.

Treating Swollen Lungs from Overinflation

Treatment focuses on relieving the lung swelling and preventing further distention damage. Key strategies include:

Adjusting Mechanical Ventilation Settings

For ventilated patients, ventilator settings must be optimized to allow deflation and prevent excessive inflation pressures. This involves:

• Lowering tidal volumes and inspiratory pressures
• Allowing more time for exhalation
• Modifying the level of PEEP (positive end-expiratory pressure)
• Performing recruitment maneuvers carefully

Administering Medications

Medications that may help treat pulmonary distention include:

• Bronchodilators like albuterol to open airways
• Steroids to reduce lung inflammation
• Analgesics to ease chest discomfort
• Diuretics to decrease fluid buildup
• Antibiotics for secondary lung infections

Providing Supplemental Oxygen

Some patients benefit from extra oxygen delivered through a nasal cannula or face mask to improve oxygenation.

Trying Noninvasive Ventilation

Using noninvasive positive pressure ventilation through a tight-fitting face mask can also support breathing without intubation risks.

Inserting Chest Tubes

In some cases, chest tubes may be inserted to remove excess air and help lung re-expansion.

Performing Surgery

Surgery is rarely needed but may be done for traumatic lung injuries or persistent air leaks.

Preventing Pulmonary Distention

For patients on ventilators, key prevention strategies include:

• Careful ventilator monitoring and settings adjustment
• Advanced ventilator modes to adapt to patient breathing
• Limiting sedation to allow spontaneous breathing
• Humidifying airways
• Repositioning/mobilizing patient regularly
• Avoiding overhydration

Preventive measures can help reduce the risk of ventilator-induced lung injury.

Recovering from Pulmonary Distention

Many patients see gradual resolution of symptoms and lung function recovery with proper treatment. But in severe cases, pulmonary distention can lead to:

• Persistent shortness of breath
• Lung scarring and fibrosis
• Respiratory failure
• ARDS development
• Death

Close monitoring and supportive care help ensure the best possible outcome. Pulmonary rehabilitation programs are often beneficial during recovery.

Long-Term Outlook

For survivors of serious pulmonary distention, the long-term prognosis depends on factors like:

• Level of

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.