Bronchopulmonary dysplasia in the stage of chronic disease in children of the first three years of life

The dissertation is devoted to the study of bronchopulmonary dysplasia (BPD) in the stage of chronic disease in children of the first three years of life. The work was carried out at the Department of Childhood Diseases of the Peoples' Friendship University of Russia and addresses the problem of the consequences of intensive therapy for respiratory distress syndrome in premature infants, which requires clarification of risk factors and clinical characteristics of the disease beyond the neonatal period.

The study characterizes the structure of respiratory diseases and pathological conditions of the respiratory organs in children with BPD in the stage of chronic disease, identifies risk factors for a severe course, compares the clinical and paraclinical data of BPD exacerbations with bronchial asthma and recurrent obstructive bronchitis, and clarifies the contribution of mycoplasmas, chlamydiae, cytomegalovirus, herpes simplex viruses types I and II, and P. carinii (Jiroveci) to the development of exacerbations. Chronic respiratory failure, pneumonia, croup syndrome, chronic bronchiolitis with obliteration, the radiological picture, concomitant diseases, and the level of total IgE in children of this group are considered separately.

Topicality of the problem

In 1985, the World Health Organization (WHO) stated that over the preceding 40 years medicine had managed to eradicate one disease — smallpox — but that 18 new diseases had appeared, including such neonatal diseases as bronchopulmonary dysplasia (BPD) and retinopathy of prematurity [87]. These diseases of newborn infants should be regarded as iatrogenic.

Bronchopulmonary dysplasia, first described in 1967 by W. H. Northway, is a severe complication of respiratory distress syndrome after mechanical ventilation with high oxygen concentrations in premature infants. In 1995, BPD was included in the Russian Classification of clinical forms of bronchopulmonary diseases in children. In its development, BPD passes through 4 stages [4; 164]. In the first three days of RDS (stage I — acute exudative). By the end of the first week of life (stage II — early subacute recovery). At weeks II–III (stage III — late subacute recovery). In the following week, zones of atelectasis with interstitial and peribronchial fibrosis combined with foci of emphysema are revealed (stage IV — chronic fibroproliferative). BPD in stage IV is regarded as a variant of chronic obstructive pulmonary pathology in children [5; 6; 88].

Domestic works devoted to bronchopulmonary dysplasia are few in number, and they mainly address the course of the disease in the neonatal period [21; 37; 39; 58; 64; 84]. At the same time, a number of unresolved problems related to BPD exist. In particular, there is an insufficient amount of information on the influence of the course of the neonatal period and of the therapy administered to the child during this period, and of other factors, on the formation and course of BPD in the stage of chronic disease [61; 82]. Literature sources poorly illuminate the clinical and paraclinical data on the state of the respiratory system and on concomitant diseases and conditions in children with BPD in the stage of chronic disease [7; 8; 17; 74]. All this points to the topicality of the problem and served as the reason for carrying out the present study.

The aim of the present work was to identify the features of the course of bronchopulmonary dysplasia in the stage of chronic disease in children of the first three years of life.

Objectives of the study:

1. To characterize the structure of respiratory pathology in children suffering from bronchopulmonary dysplasia in the stage of chronic disease.

2. To identify risk factors for the development of a severe course of bronchopulmonary dysplasia in the stage of chronic disease.

3. To compare the clinical and paraclinical data of exacerbations of bronchopulmonary dysplasia in the stage of chronic disease with other diseases accompanied by the syndrome of bronchial obstruction (bronchial asthma and recurrent obstructive bronchitis).

4. To clarify the contribution of mycoplasmas, chlamydiae, cytomegalovirus, herpes simplex viruses types I and II, and P. carinii (Jiroveci) to the development of exacerbations of bronchopulmonary dysplasia in the stage of chronic disease.

Scientific novelty

For the first time, a characterization is given of the respiratory pathology of bronchopulmonary dysplasia in the stage of chronic disease depending on the severity of the course of the disease; the transformation of bronchopulmonary dysplasia into chronic bronchiolitis with obliteration (total variant; MacLeod syndrome) in children of the first three years of life is described; the clinical and paraclinical data on the course of exacerbations of bronchopulmonary dysplasia are compared with the manifestations of bronchial asthma and recurrent obstructive bronchitis, and the features of exacerbations of bronchopulmonary dysplasia in the stage of chronic disease are identified.

For the first time, a high frequency of polymicrobial infection with microorganisms associated with bronchopulmonary dysplasia of the neonatal period in children has been established: M. hominis, M. pneumoniae, C. pneumoniae, CMV, P. carinii (Jiroveci), chlamydiae, herpes simplex viruses types I and II, and C. trachomatis.

Practical significance

Reliable differences between exacerbations of bronchopulmonary dysplasia in the stage of chronic disease and exacerbations of bronchial asthma and recurrent obstructive bronchitis have been established. Decisive importance in the diagnosis of bronchopulmonary dysplasia belongs to anamnestic data (prematurity, low birth weight, mechanical ventilation in the neonatal period, oxygen dependence at the age of 28 days of life / 36 weeks of postconceptional age, recurrent broncho-obstructive syndrome) combined with the known specific radiological characteristics (hyperinflation, a combination of increased translucency of the lung tissue with fibrosis, atelectasis, and interstitial changes) persisting in the postneonatal period.

The impairment of the health status of children with bronchopulmonary dysplasia in the stage of chronic disease, characterized by a complex of respiratory, neurological, and ophthalmological disorders, requires that the indicated contingent of children be followed up by a pulmonologist, neurologist, ophthalmologist, and (where indicated) other specialists.

Main propositions submitted for defense:

1. Bronchopulmonary dysplasia in the stage of chronic disease is a variant of obstructive lung diseases in children.

2. Exacerbations of bronchopulmonary dysplasia in the stage of chronic disease differ reliably, clinically and paraclinically, from exacerbations of bronchial asthma and recurrent obstructive bronchitis.

3. Children of the first three years of life suffering from bronchopulmonary dysplasia in the stage of chronic disease have a high degree of infection with a number of intracellular and membrane pathogens that contribute to the development of BPD exacerbations.

Approval of the work and publications

The main propositions of the dissertation were discussed at the Scientific and Practical Conference "Bronchopulmonary Dysplasia in Children" (St. Petersburg, 2005), at a meeting of the infectious diseases section of the Moscow Branch of the Union of Pediatricians of Russia (Moscow, 2005), at the XV National Congress on Respiratory Diseases (Moscow, 2005), at the X Congress of Pediatricians of Russia (Moscow, 2006), and at the All-Russian Scientific and Practical Conference "Diseases of the Small Bronchi in Children" (St. Petersburg, 2006). Nine printed works on the topic of the dissertation have been published.

Implementation of the research results

The results of the study are used in the teaching process at the Department of Childhood Diseases of the Peoples' Friendship University of Russia. The tactics of examination and complex treatment of children with bronchopulmonary dysplasia have been introduced into the practice of the infectious isolation-box wards of the Morozov Children's City Clinical Hospital and Children's Infectious Clinical Hospital No. 6 of the Northern Administrative District of Moscow.

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