Chronic Respiratory Failure
What causes chronic respiratory failure? All the information about the symptoms, causes, and treatment of this condition.
Symptoms and Causes
Respiratory failure refers to the inability of the respiratory system to perform adequate gas exchange to meet the metabolic needs of the body: the lungs fail to properly oxygenate the arterial blood and, in some cases, also fail to remove carbon dioxide adequately. When the disease develops progressively over time, it is referred to as chronic respiratory failure.
Chronic respiratory failure is classified into three types:
- Hypoxemic respiratory failure: decreased oxygen transported in the arteries because the lungs cannot oxygenate the blood.
- Hypercapnic respiratory failure: increased arterial carbon dioxide because the lungs fail to eliminate it.
- Mixed respiratory failure: both of the above conditions occur.
Based on the concentration of gases in the blood, the classification is as follows:
- Partial respiratory failure or type 1: decrease in arterial oxygen pressure below 60 mmHg.
- Global respiratory failure or type 2: arterial oxygen pressure below 60 mmHg along with an increase in arterial carbon dioxide pressure above 45 mmHg.
Symptoms
The common symptoms of respiratory failure are as follows:
- Hypoxia symptoms:
- Extreme fatigue that makes simple, routine activities difficult.
- Dyspnea: difficulty breathing, shortness of breath.
- Somnolence.
- Cyanosis: bluish coloring in the fingers and lips. In people with dark skin, a grayish or whitish color appears in the mouth, around the eyes, and beneath the nails.
- Hypercapnia symptoms:
- Blurred vision.
- Confusion.
- Headache.
- Rapid breathing.
- Irregular heart rate.
Causes
Chronic respiratory failure is the final result of a wide range of diseases, both respiratory and non-respiratory:
- Diseases causing obstruction of the airways, such as chronic obstructive pulmonary disease (COPD, the most common cause of chronic respiratory failure), bronchiectasis, or cystic fibrosis.
- Chronic lung tissue disorders, such as pulmonary fibrosis, sarcoidosis, pneumoconiosis, post-inflammatory fibrosis, or pulmonary necrosis.
- Tumors.
- Conditions that cause chest deformities, such as kyphoscoliosis or morbid obesity.
- Nervous and muscular disorders affecting the respiratory muscles, such as amyotrophic lateral sclerosis, multiple sclerosis, Parkinson’s disease, chronic polyneuropathies, muscular dystrophies, or permanent damage to the spinal cord nerves.
- Cardiovascular diseases, such as chronic heart failure.
Risk Factors
The main factors that increase the risk of developing a disease that leads to chronic respiratory failure include:
- Age: aging worsens lung function, promotes muscle weakness, and decreases chest elasticity.
- Smoking.
- Obesity.
- Prolonged exposure to pulmonary irritants, such as silica, asbestos, chemicals, or smoke.
Complications
The low oxygen concentration in the blood in chronic respiratory failure causes narrowing of the pulmonary arteries, which can lead to pulmonary hypertension. This hypertension forces the right side of the heart to work harder to pump blood, and over time, the ventricle enlarges and hardens (a condition known as cor pulmonale), eventually leading to right heart failure, a potentially fatal condition.
Prevention
The onset of lung diseases can be prevented by taking the following measures:
- Avoiding tobacco.
- Avoiding exposure to pulmonary irritants.
- Maintaining a healthy weight.
Which doctor treats chronic respiratory failure?
Chronic respiratory failure is diagnosed and treated in the pulmonology unit.
Diagnosis
In addition to studying the symptoms, medical history, and risk factors, various tests are conducted to confirm chronic respiratory failure:
- Pulse oximetry: using a device placed on the finger or ear, the oxygen saturation level in the blood and heart rate are measured.
- Arterial blood gas analysis: in a sample of arterial blood, oxygen and carbon dioxide levels are measured. This test confirms the type of respiratory failure (hypoxic, hypercapnic, or mixed).
- Chest X-ray: X-ray images can show lung conditions causing the failure. They also reveal signs of heart involvement.
- Electrocardiogram, to confirm the presence of arrhythmias. Using electrodes, the electrical activity of the heart is examined.
- Pulmonary function tests: they check the status and functioning of the lungs. These tests are also done periodically to assess the progression of the failure and the effectiveness of treatment.
- Spirometry: the patient blows into a device that records the amount of air inhaled and exhaled, as well as the exhalation speed.
- Pulmonary volume tests: similar to spirometry, this measures the volume of air contained in the lungs.
- Pulmonary diffusion capacity: this test assesses how effectively oxygen enters the blood. The patient breathes in a gas that acts as a marker, and the concentration of the gas in the exhaled air is then measured.
Treatment
The primary approach to chronic respiratory failure is the treatment of the underlying disease and any complications that may have developed. Additionally, the respiratory failure itself must be treated. Treatment options include:
- Respiratory rehabilitation: techniques and exercises to improve endurance and muscle strength and reduce breathing difficulty. Education about the disease and behavioral interventions are also provided to improve quality of life.
- Home oxygen therapy: continuous administration of supplemental oxygen to correct hypoxemia. Various methods are used:
- Portable liquid oxygen or compressed gas tank.
- Oxygen concentrator: an electrical device that separates oxygen from nitrogen in the air. There are static models that connect to the network and portable models that have batteries. In both cases, oxygen is administered through nasal cannulas or masks.
- Mechanical ventilation: if insufficient pulmonary ventilation is not corrected with the previous treatments, a machine (ventilator) is used to deliver air under pressure through a facial mask or a tube inserted into the trachea. This treatment is usually done at night, also in the patient's home.
- Pharmacological treatment depending on the cause of the respiratory failure.
