1) Department of Internal Medicine, Athena Villa dei Pini Clinic, Piedimonte Matese (CE);
2) Division of Internal Medicine, A.G.P. Piedimonte Matese (CE);
«Respiratory insufficiency: the causes of origin
Treatment
At present - despite having therapeutic resources (long-term oxygen therapy, home ventilation) capable, if implemented early, to control and / or delay the evolution of chronic respiratory failure - there is no integrated intervention program on national territory aimed at ensuring correct management of the various levels of severity of the disease.
The aids that are adopted for the treatment of this highly disabling morbid condition are:
- Pathogenetic therapy in relation to the different pathophysiological substrates;
- Long Term Oxygen Therapy (OLT);
- Home-based Mechanical Ventilation in chronically critically ill patients in clinical stability (VMD);
- Prevention of IRC flare-ups;
- Treatment of the biohumoral imbalance associated with the condition of CRI;
- Treatment of cardiovascular complications determined by the state of CRI and, in particular, by pulmonary hypertension.
The pathogenetic therapy of CRF (chronic respiratory insufficiency) is represented by a series of pharmacological measures aimed at improving the characteristic disorders of the patient with CRF, such as dyspnoea, bronchospasm, hypersecretion and cough. This form of therapy can be defined as a pathogenetic type, since it intervenes on various pathophysiological substrates of the CRI, such as, for example, the ventilo-perfusion imbalance caused by chronic broncho-obstruction (through bronchodilators, antibiotics, etc.) or damage alveolar-capillary diffusion (for example with anti-inflammatories).
Long-term oxygen therapy (OLT) means the continuous administration, for most of the daily hours, of oxygen, in order to increase the alveolar pressure of O2, in order to obtain oxyhemoglobin saturation values close to normal (> 90% ); the purpose of long-term oxygen therapy is therefore to intervene on tissue damage caused by hypoxia, trying to prevent the pathophysiological alterations induced by the condition of chronic oxygen deficiency. Generally, long-term oxygen therapy is programmed by the doctor in order to ensure values of paO2 of at least 65 mmHg or oxyhemoglobin saturation> 90%.
Home mechanical ventilation (VMD) increases the survival of patients with neuromuscular or rib cage diseases, while its use in COPD patients is effective only in selected cases.
The need to set up a pharmacological prevention program for events that cause exacerbation - such as infections or episodes of acute pulmonary vascular compromise (for example from pulmonary thromboembolism) - is given by the fact that they represent an "important cause of death for the patient with chronic respiratory insufficiency and, in any case, affect the natural history of the disease, since they are responsible for a rapid deterioration of the respiratory function that exhausts the functional reserve of the patient.
A regularization of the caloric intake and of the composition of the diet can help to improve the efficiency of the respiratory muscles. In this sense, nutritional supports based on an excess of lipids on carbohydrates and proteins in small meals during the day have been used (Pulmocare, Ensure). In fact, the clinical picture of CRI is also characterized by important biohumoral changes, mainly represented by malnutrition phenomena and changes in the hydro-electrolytic balance and acid-base balance. Malnutrition, consisting in a decrease of more than 10% with respect to the ideal weight, and / or the deficiency of hepatic proteins, such as albumin and prealbumin, are present in 25-50% of patients with chronic respiratory insufficiency; these aspects are interpreted as the consequence of a secondary hypermetabolism to the greater demands necessary to satisfy the respiratory work. It should also be emphasized that the achievement of an ideal diet is difficult in the patient with CRI; in fact, an increase in calories can have the effect of an increase in CO2 production, when lipogenesis increases or excess sugars or proteins are used.
The treatment of pulmonary cardiovascular alterations during CRI is based on different modalities:
→ Long-term home oxygen therapy is the most effective measure to obtain a reduction in pulmonary hypertension; in fact, continuous administration over 24 hours protects particularly at night, when episodes of oxyhemoglobin desaturation capable of causing pulmonary vasoconstriction phenomena can be very frequent.
→ Pulmonary vasodilators, currently little used, can be indicated in severe forms of IP. To this category belong the Ca-antagonists, the ACE-inhibitors, the alpha-blockers; however, these drugs should be used with caution due to the possible interference with systemic hemodynamics (hypotension) and with gas exchange (worsening of the ventilation-perfusion ratio due to inappropriate vasodilation in poorly ventilated areas). especially the use of diuretics, which are mainly used in the exacerbation phase and in patients with post-bronchitic emphysema (blue bloater), in whom signs of right ventricular engagement and peripheral stasis are particularly evident.
Procedures to be implemented in urgency:
- venous access
- ecg monitoring
- pulse oximetry
- PA monitoring
- administration of oxygen
- blood gas analysis, if possible in ambient air
- routine blood sampling for dyspnoic patients.
- 12-lead ecg
- rapid physical examination with clinical history and drug anamnesis
Prevention
Primary prevention (recognition and elimination of the causes of disease) is implemented first of all with the abolition of smoking, which alone is responsible for about 70% of deaths from chronic respiratory failure. Currently, smoking cessation is based on a program articulated, which includes behavioral education techniques, single or group, and - in case of failure - the use of pharmacological aids as replacement therapy, with the use of systemic, transdermal or aerosol nicotine, or, in the absence of contraindications, of clonidine. Recently, favorable results have also been obtained with some antidepressants (buspirone). The screening of subjects with states predisposing to the development of chronic respiratory disease (eg hereditary deficiencies of a1-antitrypsin, mucoviscidosis, lung damage related to work activity) is of similar importance.
Secondary prevention (early diagnosis of the disease) is carried out through the execution of respiratory functional tests on a large sample, in order to identify initial forms of the disease, on the basis of data acquired from the spirometric and radiographic investigation. Finally, tertiary prevention (implementation of measures that try to prevent the progression of the disease) is based on monitoring and home treatment of the patient, which currently constitute an effective method of controlling the causes of social invalidity linked to the CRI.
By Correspondence: Dr. Luigi Ferritto
Department of Internal Medicine Clinical Respiratory Physiopathology Unit "Athena" Villa dei Pini
Piedimonte Matese (CE)
