What is Hyperinflated Lungs and How to Manage it?

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. Especially, health care professionals associate hyperinflated lungs with chronic obstructive pulmonary disease (COPD).

Pulmonary hyperinflation is the medical name for hyperinflated lungs. Furthermore, overinflated lungs restrict the amount of air you inhale, depleting circulating oxygen in the body. This results in reduced life expectancy due to 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.

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

However, 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 the patients to 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, people with COPD cannot expel all the air they inhale, resulting in an elevated FRC.

When an individual exercises with dynamic hyperinflation. Consequently, the breathing rate and tidal volume (the amount of air inhaled with each breath) increase during activity or exertion. Hence, this causes 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 – Asthma results in inflamed airways and leads to airway obstruction. Usually, pollen grains, smoke, and different infectious agents exacerbated this disease. Following, asthma can hinder life.
• Bronchiectasis – t is a chronic respiratory condition in which airways are permanently widened. Additionally, it can lead to death.
• Bronchiolitis – It inflames the smallest airways in the lungs, a condition typically found in infants or children under 2 years old.
• Cystic Fibrosis – Furthermore, cystic fibrosis 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. Since, 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.

However, 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

Hyperinflated lungs significantly reduce your ability to exercise, a condition known as exercise intolerance. Additionally, when suffering from this condition, even normal activities can leave you feeling exhausted and experiencing shortness of breath or sudden dyspnea.

Diagnosis of Hyperinflated Lungs

Moreover, 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.

Furthermore, 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 due to the constant inflation of the lungs

What do Hyperinflated Lungs Look Like:

To detect the causes of hyperinflated lungs and determine the appropriate treatment, the following imaging tests can be performed:

• 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. In addition, it is also used to assess overall function and abnormalities in the heart.

Additionally, your physician might also perform Pulmonary Function Tests (PFTs) to detect the pulmonary issue. Subsequently, 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. Consequently, their interobserver variability is small.

Additionally, 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. Subsequently, 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.

In addition, 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:

It is a pathological finding of chronic obstructive pulmonary disease (COPD). Moreover, 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

In addition to the previously discussed symptoms and imaging findings, several pathological features of hyperinflated lungs can provide valuable information for determining the most appropriate management and treatment strategies, ultimately improving hyperinflated lung life expectancy.

• Destruction of the parenchyma of the lungs:

The equilibrium of forces between the inward elastic recoil pressure of the lungs and the outward elastic recoil pressure of the chest wall determines the air volume. Following, the air in the remaining in the lungs of healthy individuals after expiration is air volume.

• 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.

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

• Langerhans cell histiocytosis
• Lymphangioleiomyomatosis

Complications of Hyperinflated Lungs

The most troublesome complication of hyperinflated lungs is that it can cause cardiovascular problems. Hence, pulmonary hyperinflation can affect cardiac functioning drastically.

Consequently, 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. In the end,it will result in heart failure.

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

At this time, 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. In addition, 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. Bronchodilators, typically inhaled, can also 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. Consequently, elevating oxygen levels in the body 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.

Management for Hyperinflated Lungs

Studies show COPD patients with lung hyperinflation have lower lung function but higher bronchodilator response. Additionally, 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.

Lastly, 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. Furthermore, 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

In conclusion, our doctors at lung and sleep center in Michigan can help in diagnosing hyperinflated lungs. They utilize a combination of physical examinations, imaging tests, and pulmonary function tests (PFTs) to diagnose and assess lung conditions. Furthermore, it can be treated with bronchodilators, breathing exercises, oxygen therapy, and lung volume reduction surgery.

Moreover, 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.