Various types of chronic and acute pathologies of the bronchopulmonary system (pneumonia, bronchiectatic disease, atelectasis, desiminated processes in the lung, cavernous cavities, abscesses, etc.), anemia, damage to the nervous system, and hypertension can lead to defects in lung ventilation and respiratory failure. tumors of the mediastinum and lungs, vascular diseases of the heart and lungs, etc.
This article discusses the restrictive type of respiratory failure.
Pathology Description
Restrictive respiratory failure is characterized by a decrease in the ability of lung tissue to fall and expand, which is observed with pneumothorax, exudative pleurisy, adhesions in the pleural cavity, pneumosclerosis, limited mobility of the skeleton of the ribs, kyphoscoliosis, etc. Respiratory failure with such pathologies occurs due to the limited depth of inhalation, which is the maximum possible.
Forms
Restrictive respiratory failure due to defects in alveolar ventilation due to the limited stretching of the lungs. Two forms of ventilation respiratory failure are distinguished: pulmonary and extrapulmonary.
Restrictive extrapulmonary ventilation respiratory failure develops due to:
- impaired function and structure of the respiratory muscles;
- restrictions (violations) in the mobility of the diaphragm and chest;
- increase in pressure in the pleural cavity.
Cause
The causes of restrictive respiratory failure should be determined by the doctor. Restrictive pulmonary ventilation respiratory failure develops due to a decrease in lung distensibility, which is observed in congestive and inflammatory processes. Pulmonary capillaries overflowing with blood, and interstitial edematous tissue prevent the alveoli from fully straightening, squeezing them. In addition, under these conditions, the extensibility of the interstitial tissue and capillaries decreases.
Symptoms
The restrictive form of respiratory failure is characterized by a number of symptoms.
- Decrease in indicators of pulmonary capacity as a whole, their residual volume, VC (this indicator reflects the level of pulmonary restriction).
- Defects in the regulatory mechanisms of external respiration. Respiratory disorders also appear due to impaired functioning of the respiratory center, as well as its efferent and afferent connections.
- Manifestation of alveolar restrictive hypoventilation. Clinically significant forms are labored and apneustic breathing, as well as its periodic forms.
- Due to the previous cause and defects of the physico-chemical membrane state, the disorder of the transmembrane ion distribution.
- Fluctuations in neuronal excitability in the respiratory center and, as a consequence, changes in the depth and frequency of respiration.
- Disorders of external respiratory central regulation. The most common causes: neoplasms and injuries in the medulla oblongata, compression of the brain (with inflammation or swelling, hemorrhages in the brain or ventricles), intoxication (for example, drugs, ethanol, endotoxins that form when liver failure or uremia), endotoxins , destructive transformations of brain tissue (for example, with syphilis, syringomyelia, multiple sclerosis and encephalitis).
- Defects in the afferent regulation of the respiratory center, which are manifested by excessive or insufficient afferentation.
- Deficit of excitatory afferentation of alveolar restrictive hypoventilation. Decreased tonic nonspecific activity of neurons located in the reticular formation of the brain stem (acquired or inherited, for example, with an overdose of barbiturates, narcotic analgesics, tranquilizers and other psycho-and neuroactive substances).
- Excessive stimulating afferentation of alveolar restrictive hypoventilation. Symptoms are as follows: rapid shallow breathing, that is, tachyknife, acidosis, hypercapnia, hypoxia. What is the pathogenesis of restrictive respiratory failure?
- Excessive inhibitory afferentation of alveolar restrictive hypoventilation. The most common causes: increased irritation of the mucous membranes of the respiratory system (when a person inhales irritating substances, for example, ammonia, with acute tracheitis and / or bronchitis during inhalation of hot or cold air, severe pain in the respiratory tract and / or chest ( for example, with pleurisy, burns, injury).
- Defects in nervous efferent respiratory regulation. They can be observed due to damage at various levels of the effector pathways that regulate the functioning of the respiratory muscles.
- Defects of the cortico-spinal paths to the muscles of the respiratory system (for example, with syringomyelia, spinal cord ischemia, trauma or tumors), which leads to the loss of conscious (voluntary) control of breathing, as well as the transition to “stabilized”, “machine-like”, “automated” »Breathing.
- Lesions of the pathways leading to the diaphragm from the respiratory center (for example, with spinal cord injury or ischemia, polio or multiple sclerosis), which are manifested by a loss of respiratory automatism, as well as a transition to an arbitrary type of breathing.
- Defects of the spinal descending paths, nerve trunks and spinal cord motor neurons to the respiratory muscles (for example, with spinal cord ischemia or trauma, botulism, poliomyelitis, conduction blockade of nerves and muscles when using medications curare and myasthenia gravis, neuritis). Symptoms are as follows: a decrease in the amplitude of breathing and periodic apnea.
The difference between restrictive and obstructive respiratory failure
Obstructive respiratory failure, as opposed to restrictive, is observed with obstructed air passage through the bronchi and trachea due to bronchospasm, bronchitis (inflammation of the bronchi), penetration of foreign bodies, compression of the trachea and bronchi by a tumor, narrowing (stricture) of the bronchi and trachea, etc. In this case, the functional capabilities of external respiration are impaired: full inhalation and, in particular, exhalation are difficult, the respiratory rate is limited.
Diagnostics
Restrictive respiratory failure is accompanied by a limited filling of the lungs with air due to a decrease in the respiratory lung surface, a part of the lung being pulled out of breathing, a decrease in the elastic characteristics of the chest and lung, as well as the ability of lung tissue to stretch (hemodynamic or inflammatory pulmonary edema, extensive pneumonia, pneumosclerosis, pneumoconiosis etc.). In the event that restrictive defects are not combined with violations of patency of the bronchi, which are described above, the resistance of the paths carrying air does not increase.
The main consequence of the restrictive (restrictive) ventilation disorders that are detected by spirography of the classical type is an almost proportional decrease in most of the pulmonary capacities and volumes: FEV1, DO, FEV, ZHEL, ROvyd, Rovd, etc.
Computer spirography shows that the flow-volume curve is a copy of the correct curve in a reduced form due to a decrease in the total pulmonary volume, which is shifted to the right.
Diagnostic criteria
The most significant diagnostic criteria for ventilation restrictive disorders, which allow you to fairly reliably identify differences from obstructive defects:
- normal or even elevated Tiffno index (FVC / FEV1);
- an almost proportional decrease in lung capacities and volumes, which are measured by spirography, and flow indicators, that is, accordingly, unchanged or normal shape of the flow-volume loop curve, which is shifted to the right side;
- the decrease in RVD (reserve volume of inspiration) is almost proportional to RVVd (that is, the volume of expiration of the reserve).
It should be noted once again that with diagnostic measures of restrictive ventilation disorders in their pure form, one cannot rely solely on a decrease in VC. The most reliable diagnostic and differential signs are the absence of transformations in the appearance of the expiratory portion of the flow-volume curve and a proportional decrease in the volume of radiation and the volume of radiation.
How to act the patient?
If symptoms of restrictive respiratory failure appear, consult a physician. It may also be necessary to consult specialists in other areas.
Treatment
Restrictive pulmonary diseases require prolonged home ventilation. Her tasks are as follows:
- improving the quality of life;
- extension of human life;
- improvement of the respiratory apparatus.
Most often, during prolonged home pulmonary ventilation, patients with restrictive respiratory failure use nasal masks and portable respirators (in some cases a tracheostomy is used), while ventilation is done at night, and also for several hours in the afternoon.
Ventilation parameters are usually selected in stationary conditions, and then regular monitoring of the patient and maintenance by specialists at home are carried out. Most often, during prolonged pulmonary ventilation at home, patients with chronic respiratory failure require a supply of oxygen from tanks with liquid oxygen or from an oxygen concentrator.
So we examined the restrictive and obstructive types of respiratory failure.