Hyperinflated lungs are a medical condition in which lungs are distended beyond their usual adequate size. The expansion is due to ensnared air. Any internal systemic cause can decrease the capacity of your lungs to exhale the right amount of air and can subsequently result in lungs overinflation. However, this respiratory condition is most commonly associated with chronic obstructive disease (COPD).
The other name for hyperinflated lungs is pulmonary hyperinflation. 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. Apart from respiratory issues, hyperinflated lungs can culminate in cardiac complications as well.
In this blog, we will have a comprehensive look at the hyperinflated lung causes and their symptoms. Along with that, we shall also discuss its diagnostic and treatment approach.
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
The diminished ability to exercise is known as Exercise intolerance. This comes with hyperinflated lungs and is relatively common. You will end up feeling exhausted and might experience shortness of breath or instant dyspnea, even when you are performing normal activities.
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 the hyperinflation of the lungs, the elevated pressure in the thoracic (chest) cavity can impart damaging changes to the left ventricle of the heart gradually.
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 hyperinflation and pulmonary hypertension can not only cause shortness of breath, fatigue, exercise intolerance, and difficulty inhaling but can be a potential reason behind the cardiac arrest.
Causes of Hyperinflated Lungs
The crucial cause behind hyperinflated lungs is a chronic obstructive pulmonary disease (COPD). Different medical conditions characterize this respiratory condition.
Emphysema
In this respiratory condition, air sacs are irreversibly enlarged and destroyed. This results in breathing issues eventually.
Chronic Bronchitis
In this respiratory condition, the main airways of the lungs, known as “bronchi”, are narrowed and become 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 usually found in infants or children under 2 years of age.
Cystic Fibrosis
It is a fatal and inherited 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 obstructs the functioning of digestive enzymes.
Diagnosis of Hyperinflated Lungs
The diagnosis of hyperinflated lungs customarily includes a thorough physical examination, a look at your general medical history, and routine imaging tests.
During the physical examination, the doctor will hear odd breathing sounds with a stethoscope. Sounds of valve regurgitation or a heart murmur can also be detected. A patient suffering from hyperinflated lungs can also have a barrel-shaped chest. The chest will appear inflated most of the time.
Following imaging tests can be done to detect hyperinflation of the lungs.
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
This test reviews all cardiac issues.
Your physician might also perform Pulmonary Function Tests (PFTs) to detect the pulmonary issue. It is a series of non-invasive tests that reveals how better and adequately your lungs are performing. Pulmonary Function Tests (PFTs) calculate lung volume, lung capacity, rates of airflow, and the interchange of gases.
Due to the variability of symptoms, hyperinflated lungs can be tough to diagnose and usually requires a pulmonologist who has acquired specialization in pulmonary diseases.
Pathology of Hyperinflated Lungs
The following can be pathological features of hyperinflated lungs.
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.
If pulmonary parenchymal destruction occurs due to aging or other factors, for example, emphysema, then it can lead to the displacement of the lung volume to a higher volume.
Defects in Airway
Mucosal oedema, remodeling or clogging of mucus in airways, can result in hyperinflated lungs. The expiratory airflow in such scenarios is elevate, especially during exercise.
Some interstitial diseases also cause hyperinflated lungs, which include;
- Langerhans cell histiocytosis
- Lymphangioleiomyomatosis
Radiographic features
Following are the radiographic features of hyperinflated lungs:
Flattened hemidiaphragmatic contours
It is assumed as one of the most crucial indicators of hyperinflated lungs. Their interobserver variability is small. It is better seen on the lateral chest radiograph and comprises of lesser height and convexity of the hemidiaphragm. 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. When the arch height is lesser than 2.5 cm, it is consider pathological.
Retrosternal space measurement
A straight horizontal line is sketches from the point of 3 cm beneath the junction of the manubrium and sternal body, also on the posterior side of the sternum and at the ascending aorta point. 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
Following are the features seen on the CT scan.
- Air trapping – observed best on expiration.
- Calculating the length of the anterior junctional line
Saber-sheath trachea
It is a pathological finding of chronic obstructive pulmonary disease (COPD).The diameter of the trachea is decrease in the coronal plane and increase in the sagittal plane. It can also 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.
Treatment of Hyperinflated Lungs
There are numerous treatments available for hyperinflated lungs. Some treatments are invasive, and some are not. Following is the list of treatments for lung hyperinflation.
Bronchodilators
These medicines help in expanding and relaxing the lungs. Bronchodilators are available by prescription and can help to 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 in relieving your breathing. Usually, bronchodilators are inhale but can be taken in liquid, tablet, and 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. This breathing exercise slows down your breathing and enhances your inspiration of oxygen into the lung.
Oxygen Therapy
If someone is dealing with hyperinflated lungs or COPD, then supplemental oxygen therapy can be an essential life saver for them. Oxygen therapy can effectively elevate the levels of oxygen in the body and sustain them on a normal threshold.
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, but if your condition has been characterize by features that can only be cure through surgical intervention, then there are no other options left. At this point, no medications can provide relief or alleviate your symptoms. If carried out successfully, lung-volume reduction surgery can improve hyperinflated lung life expectancy and quality of life.
Conclusion
Hyperinflated lungs are a medical condition associate with COPD and other respiratory disorders. In this disorder, the lungs over inflate, which leads to shortness of breath (dyspnea), fatigue, tiredness, difficulty inhaling, and exercise intolerance. Asthma, cystic fibrosis, and bronchiectasis are count as other probable causes of the hyperinflation of the lungs.
It can be diagnose at our lung and sleep center in Michigan with our doctor’s physical examination, imaging tests, and pulmonary function tests (PFTs). Hyperinflated lungs can be treat with bronchodilators, breathing exercises, oxygen therapy, and lung volume reduction surgery.
