Chronic respiratory failure

What is respiratory failure?

The function of the respiratory system is to obtain oxygen from the ambient air and contribute it to the blood as well as to expel carbon dioxide (CO2) originated in the metabolism of the different organs and systems and transported through the blood to the lungs. . A failure in this function implies a failure of the respiratory system.

Thus, respiratory failure is the failure of the respiratory system in its function of gas exchange, necessary for the metabolic activity of the body. It is called conical when it occurs in a sustained manner over a long period of time.

How is it produced?

The mechanisms of production of arterial hypoxemia (low oxygenation of the blood) are the same as in acute respiratory failure. That is, there is a compromise of gas exchange either due to alterations in ventilation, perfusion or diffusion of these gases at the pulmonary level. Among the causes:

Symptoms

The clinical data help to suspect the presence of respiratory failure, distinguish between acute and chronic respiratory failure, find out its production mechanism and know the existence of associated complications.

In general, it presents the same symptoms as acute respiratory failure, although in a more long-lasting way and therefore better tolerated. It can also present symptoms derived from compensation mechanisms such as headache (due to vasodilation and increased CO2). Patients with chronic respiratory failure can, however, exacerbate, so the following should be considered:

Diagnosis

The physical examination has low sensitivity and specificity for the diagnosis of respiratory failure, although it is useful in its causal diagnosis. Special emphasis should be placed on data such as the presence of cyanosis (bluish coloration of the most distal parts), clubbing (drumstick fingers, widened in the terminal phalanx), alterations in the shape of the rib cage, as well as in the pulmonary and cardiac auscultation that guide us towards the cause of respiratory failure.

The rest of the complementary examinations that can be carried out are the same as in acute respiratory failure: arterial blood gases. Chest X-ray, blood tests, electrocardiogram, respiratory function tests, CT, fiberoptic bronchoscopy, pulmonary arteriography etc.

Treatment

The goal of treatment is to improve quality of life and survival, by controlling functional deterioration and preventing and treating complications with minimal side effects.

smoking cessation together with oxygen therapy are the only measures that have been shown to improve survival.

The education of the patient and his family is important to help the correct compliance with the treatment.

Annual flu vaccination is recommended. The reduction of secretions is achieved by quitting tobacco and avoiding other irritants. Oral fluids and sprays are only helpful if you are dehydrated. Mucolytics and antioxidants have not proven their worth. respiratory physical therapy may be helpful.

Rehabilitation improves tolerance to exertion and quality of life.

antibiotic treatment is especially indicated in moderate or severe exacerbations and should be started in the presence of at least two of the following symptoms: fever, increased respiratory distress and / or changes in the characteristics of sputum. However, if these data suggestive of respiratory infection do not exist, it is not necessary to prescribe antibiotics.

Pharmacological treatment must be individualized for each patient.

Chronic home oxygen therapy produces an increase in survival and a decrease in hospital admissions in patients with chronic obstructive pulmonary disease and respiratory failure. There is a relationship between longer survival and the number of hours of oxygen therapy. In general, oxygen should be maintained at least 16 hours a day.

Precautionary measures

It generally depends on the cause of the respiratory failure. In cases of environmental exposure, abandonment of work or labor protection measures can prevent or at least delay its appearance. Likewise, smoking cessation is essential, whatever the cause of respiratory failure. As previously discussed, flu vaccination can prevent complications that worsen respiratory failure.

• Alterations of the muscles and nerves of the rib cage due to trauma and spinal tumors and other neuromuscular diseases such as myasthenia gravis, amyotrophic lateral sclerosis (ALS), among others ...
• Alterations of the thoracic structures due to Obesity, deformity of the thoracic wall, chronic pleural injuries
• Diseases of the upper airways due to obstructive sleep apnea syndrome or organic or functional diffusion of the vocal cords
• Diseases of the lower respiratory tract and pulmonary by Diseases with chronic obstruction (chronic bronchitis, emphysema,, bronchiectasis, mucoviscidosis or cystic fibrosis); Diffuse interstitial lung diseases (pneumoconiosis, collagenosis ...); Pulmonary vascular diseases (pulmonary hypertension, pulmonary arteriovenous malformations ...); Surgical resection of the lung parenchyma ...
• Congenital cyanotic heart disease
• The existence of respiratory distress (dyspnea) which is the main symptom, its evolution time, the patient's tolerance and the association of respiratory distress while lying down (orthopnea) or the appearance of sudden respiratory distress at night (paroxysmal nocturnal dyspnea)
• Other symptoms such as cough, expectoration, hemoptysis (bloody sputum), audible wheezing (whistling), chest pain that increases with breathing (pleuritic pain) or fever that can lead to superinfection.
• Toxic habits, especially smoking
• Treatment with respiratory center depressant drugs such as benzodiazepines.
• Associated symptoms of neuromuscular dysfunction (nerves and musculoskeletal system involved in respiratory movements) or sleep apnea syndrome
• Work or occupational history (work in coal mines, anthracites, loggers ...) or previous manipulation of the upper airway.