Complications of COPD

Dynamics of the infectious and inflammatory process

The course of COPD is inextricably linked with chronic inflammation and the regular addition of secondary infection. In the early stages of the disease (as clinical practice observing smoking patients shows), patients often experience wave-like coughing and episodes of temperature elevation to febrile values (38–39 °C). In such cases, penicillin-class drugs are traditionally used to suppress the infectious agent.

However, over time, the microflora of the airways changes. With a prolonged course of the disease, Streptococcus is frequently detected in sputum cultures, which necessitates a mandatory switch of antibacterial therapy to amoxicillin, taking into account pathogen susceptibility. Unresolved secondary infection can lead to the development of severe pneumonia. To prevent infectious complications and improve sputum rheology, maintaining adequate fluid balance (hydration) is critically essential. In the presence of concomitant bronchiectasis, postural drainage becomes a mandatory component of treatment, ensuring effective secretion clearance.

Progression of respiratory failure

As the disease progresses, bronchial obstruction steadily increases, which is clinically manifested by worsening dyspnea and the appearance of cyanosis. Functional pulmonary parameters rapidly deteriorate. In a typical patient with a long smoking history, vital capacity (VC) may drop to a critical 2 liters. At the same time, the Tiffeneau index drops to 50%, which is a marker of pronounced airway obstruction.

In later stages, chronic respiratory failure develops. It is accompanied by severe hypoxemia, which, in the absence of adequate oxygen therapy, can cause the patient's death. To increase exercise tolerance and strengthen the respiratory muscles during remission, special rehabilitation physical exercises are indicated.

Development of cor pulmonale

One of the most formidable complications of COPD against the background of long-standing emphysema and pneumosclerosis is chronic cor pulmonale (cor pulmonale). It is characterized by the development of right ventricular failure with systemic venous congestion. The clinical picture includes pronounced hepatomegaly (enlargement of the liver) and the appearance of persistent peripheral edema.

The diagnosis is confirmed by characteristic ECG signs of right ventricular hypertrophy:

• Appearance of tall R waves in leads III, aVF, V1–V2.
• Appearance of deep S waves in left precordial leads (V5–V6).

Therapy for this complication requires a comprehensive approach. To combat hypoxia, oxygen therapy is mandatory, and diuretics, specifically spironolactone, are added to the treatment regimen to manage the edematous syndrome.

Main causes of death in COPD

The prognosis for patients with severe forms of the disease remains serious. Analysis of the clinical picture highlights several key causes of mortality:

1. Severe exacerbations — act as the main cause of death.
2. Decompensation of cor pulmonale (right ventricular failure).
3. Acute cardiovascular events. It has been proven that in the first 5 days from the onset of an exacerbation, the risk of myocardial infarction increases by more than 2 times.
4. Severe pneumonia occurring against the background of a superimposed secondary infection.
5. Chronic respiratory failure with severe hypoxemia (especially in patients not receiving oxygen therapy).

Class and exam questions

What else to study on this topic

• Principles of etiotropic and pathogenetic therapy for COPD
• Methods for improving sputum rheology: hydration and postural drainage
• The role of physical training in the rehabilitation of patients with pulmonary pathology
• Dynamics of functional pulmonary parameters (VC, Tiffeneau index) during the progression of obstruction

Other topics in the "Respiratory System" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.