Understanding Hyperinflated Lungs and its Management

Hyperinflated lungs refer to a medical condition where the lungs are expanded beyond their usual size due to trapped air. Various internal systemic factors can reduce the ability of the lungs to exhale the proper amount of air, leading to overinflation. This respiratory condition is typically associated with chronic obstructive pulmonary disease (COPD).

Pulmonary hyperinflation is the medical name for hyperinflated lungs. Overinflation of the lungs means that you are restricted in the amount of air you inhale. This results in a depleted amount of circulating oxygen in the body. Hyperinflated lungs life expectancy is reduced, because of respiratory issues and cardiac complications.

In this blog, we will comprehensively examine the hyperinflated lungs causes, symptoms, diagnosis, and treatment.

What is the Clinical Importance of Hyperinflation in COPD Patients?

It holds significance for COPD patients as it contributes to dyspnea, increased morbidity, exercise tolerance and overall reduction in physical activity.

Both pharmacological and non-pharmacological therapies have demonstrated efficacy in minimizing hyperinflation and delaying the onset of ventilatory restriction.

Some COPD patients suffer from dynamic hyperinflation of the lungs which causes a reduction in hyperinflated lungs life expectancy. Dynamic hyperinflation occurs when a new breath is inhaled before the lung has reached its static equilibrium volume.

In simple terms, the lungs fail to exhale completely before they inhale a new breath of air, leading to the trapping of air in the lungs and causing inhale and exhale to occur when the lungs are full.

This figure shows COPD patient is green line, and the healthy individual is blue line. In normal breathing, the lungs exhale and inhale the same amount of air with each breath. This means that the amount of air remaining in the lungs after exhalation known as functional residual capacity (FRC) remains constant. However, even at rest, the FRC is elevated in persons with COPD because of their inability to expel all of the air they inhale.

When an individual exercises with dynamic hyperinflation. The breathing rate and tidal volume (the amount of air inhaled with each breath) increase during activity or exertion. This can cause the functional residual capacity to rise even higher since the time it takes to exhale is insufficient to eliminate all of the inhaled air.

Hyperinflated Lung Causes

One of the crucial reasons for hyperinflated lung causes is chronic obstructive pulmonary disease, and understanding the underlying conditions is essential in determining the associated impact on hyperinflated lung life expectancy.

Multiple conditions, as mentioned below, can affect hyperinflated life expectancy.

• Emphysema – In this respiratory condition, air sacs become enlarged and destroyed, leading to breathing difficulties.
• Chronic Bronchitis – In this condition, the main airways in the lungs, called bronchi, become narrowed and clogged.
• Asthma – This disease is exacerbated by multiple triggers, such as pollen grains, smoke, and different infectious agents. Asthma results in inflamed airways and leads to airway obstruction.
• Bronchiectasis – It is a chronic respiratory condition in which airways are permanently widened.
• Bronchiolitis – It is a respiratory condition in which the smallest of the airways are inflamed. This is typically found in infants or children under 2 years.
• Cystic Fibrosis – It is a fatal and genetic disorder that affects not only the respiratory tract but also the digestive tract. The causative factor is a defective gene that triggers the formation of thick mucus and eventually clogs the airways. The gene also hinders the function of digestive enzymes.

What are the Symptoms of Hyperinflated Lungs?

It can be as tough as an old boot to differentiate the signs and symptoms of hyperinflated lungs from the basal systemic condition that is the real cause behind it.

The following can be the possible signs and symptoms of hyperinflated lungs.

• Difficulty in inhaling
• Struggling to breath
• Shortness of breath / Dyspnea
• Fatigue
• Depleted body energy/ Dizziness

Exercise intolerance refers to the reduced ability to exercise and is often accompanied by hyperinflated lungs, which is a relatively common condition. When suffering from exercise intolerance, you may feel exhausted and experience shortness of breath or sudden dyspnea even when performing normal activities.

Diagnosis of Hyperinflated Lungs

Pulmonary hyperinflation can be difficult to diagnose since its symptoms overlap with those of other conditions. A consultation with a lung disease specialist is usually necessary and can increase hyperinflated lungs life expectancy.

The diagnosis of hyperinflated lungs normally includes a thorough physical examination, a look at your general medical history, and routine imaging tests.

During the physical examination, the doctor will listen for abnormal breathing sounds with a stethoscope and may also detect valve regurgitation or a heart murmur. Patients with hyperinflated lungs often have a chest that is shaped like a barrel and appears inflated most of the time.

What do Hyperinflated Lungs Look Like:

Following imaging tests can be done to detect hyperinflation lungs causes and come up with an appropriate treatment.

• Chest X-rays – They will provide detailed and intricate images of the lung, heart, vessels (both major and minor), and airways.

• Computed tomography (CT) scan – It presents multiple X-ray images to formulate a three-dimensional image of the chest cavity. CT scan composites in “slices”.
• Echocardiogram – It uses sound waves to create detailed images of the heart’s structure, chambers, and valves. It is used to assess overall function and abnormalities in the heart.

Your physician might also perform Pulmonary Function Tests (PFTs) to detect the pulmonary issue. It is a series of non-invasive tests that reveal how better and adequately your lungs are performing. It calculates lung volume, lung capacity, rates of airflow, and the interchange of gases.

Radiographic features

By identifying the features of hyperinflated lungs, it can be diagnosed early and improve the hyperinflated lungs life expectancy.

Plain radiograph

• Flattened hemi-diaphragmatic contours

It is assumed as one of the most crucial indicators of hyperinflated lungs. Their interobserver variability is small.

To calculate, we can draw a line joining the sternophrenic angle and the posterior costophrenic angle. The arch height should be more than or equal to 2.5 cm. However, if the height is less than 2.5 cm, it is considered pathological.

• Retrosternal space measurement

A straight horizontal line is sketched from the point of 3 cm beneath the junction of the manubrium and sternal body, on the posterior side of the sternum, to the point where the ascending aorta begins. The distance of retrosternal space should be equal to 2.5cm.

• Air trapping

If we compare two radiographs, the maximum inspiration and expiration, along with the vertical movement of the diaphragm, should be less than 3cm.

More features can include the following.
– Air is present beneath the heart.
– Elevated anteroposterior diameter of the chest, which will lead to a barrel-shaped chest
– Hyperlucent angles

CT Scan features

On the CT scan, the following features are observed: air trapping, which is best seen on expiration, and the length of the anterior junctional line is calculated.

• Saber-sheath trachea

The diameter of the trachea is decreased in the coronal plane and increased in the sagittal plane. In addition, it can be seen on the chest radiograph by comparing the posteroanterior and lateral projections.

• Vascular changes

This can be an indirect sign of pulmonary injury.
It is seen prominently in emphysema, in which lung parenchyma is destroyed.

Pathology of Hyperinflated Lungs

The following can be pathological features of hyperinflated lungs that can help determine management and treatment and in turn better the hyperinflated lung life expectancy.

• Destruction of the parenchyma of the lungs

In healthy individuals, the air volume reaching the lungs after expiration is impacted by the equilibrium of forces between the inward elastic recoil pressure and outward elastic recoil pressure of the lungs and the chest cavity’s wall.

In addition, there are some interstitial diseases caused by hyperinflated lungs, which include;

• Langerhans cell histiocytosis
• Lymphangioleiomyomatosis

• Defects in Airway

Mucosal edema, remodeling, or clogging of mucus in airways, which are hyperinflated lung causes and can result in difficulty breathing and other respiratory problems. The expiratory airflow in such scenarios is elevated, especially during exercise.

Complications of Hyperinflated Lungs

The most troublesome complication of hyperinflated lungs is that it can cause cardiovascular problems. Pulmonary hyperinflation can affect cardiac functioning drastically. With the course of hyperinflation of the lungs, the elevated pressure in the thoracic (chest) cavity can impart damaging changes to the left ventricle of the heart.

These functional variations in the heart can dwindle the ability of the ventricle to pump blood out of the heart. This will result in heart failure.

As discussed above, pulmonary hypertension and hyperinflated lungs causes shortness of breath, fatigue, exercise intolerance, and cardiovascular complications.

The impact of hyperinflated lungs life expectancy varies, often depending on the complication and management

Treatment of Hyperinflated Lungs

The type of treatment depends on hyperinflated lungs causes. Therefore, some of the methods are invasive while others are not. Below is a list of treatments for lung hyperinflation.

• Bronchodilators – These medicines help in expanding and relaxing the lungs. They are available by prescription and can help treat various lung conditions such as chronic obstructive pulmonary disease (COPD), asthma, cystic fibrosis, and bronchiolitis.
• They function by widening and relaxing the airways and help you breathe easily. Usually, bronchodilators are inhaled but can be taken in liquid, tablet, or injectable forms.
• Breathing exercises – Pursed-lipped breathing can help to expand the airway. It is a breathing technique in which a person breathes through their nose and gradually exhales via their mouth while the lips should pucker.
• Oxygen Therapy – Supplemental oxygen therapy can be a life-saving option for those dealing with hyperinflated lungs causes. By effectively elevating oxygen levels in the body, it can help maintain normal oxygen thresholds.
• Lung-volume Reduction Surgery – Surgery is typically the last resort to any ailment. Lung-volume surgery is among the treatment options for chronic bronchitis, chronic obstructive pulmonary disease (COPD), and hyperinflated lungs.

Generally, surgical intervention is not a common treatment approach for any severe respiratory disorder.

Studies show COPD patients with lung hyperinflation have lower lung function but higher bronchodilator response. The response rate is almost 69.5%–75.3% which makes bronchodilators an efficient treatment for hyperinflated lungs and leading to an increased hyperinflated lungs expectancy.

Additionally, late at the stage of hyperinflated lungs no medications can provide relief or alleviate your symptoms. If carried out successfully, lung-volume reduction surgery can improve hyperinflated lungs life expectancy and overall quality of life.

Risk Factor of hyperinflated lungs

The primary hyperinflated lungs cause is chronic obstructive pulmonary disease (COPD however, several risk factors can increase the likelihood of developing this condition.

• Smoking: Smoking cigarettes is a major risk factor for pulmonary hypertension. It is a major contributor to COPD, especially chronic bronchitis and emphysema.
• Environmental Pollution: Air pollution can contribute to the development and worsening of respiratory disorders.
• Respiratory Infections: Frequent or acute respiratory infections, particularly if untreated or poorly managed, can contribute to chronic lung diseases and hyperinflated lungs. Additionally, individuals with pre-existing respiratory conditions, such as asthma or bronchiectasis are also at risk.
• Alpha-1 Antitrypsin Deficiency: A genetic condition known as alpha-1 antitrypsin deficiency can predispose individuals to early-onset COPD, which can contribute to hyperinflated lungs.

Conclusion

Our doctors at lung and sleep center in Michigan can help in diagnosing hyperinflated lungs. They perform physical examination, imaging tests, and pulmonary function tests (PFTs). Furthermore, it can be treated with bronchodilators, breathing exercises, oxygen therapy, and lung volume reduction surgery.

Hyperinflated lungs life expectancy can be increased with proper management, treatment plans, and lifestyle adjustments. An individual should visit their healthcare provider regularly or visit a Lung and sleep clinic.