Moshkovska L. Lung protection during cardiopulmonary bypass in children with congenital heart defects

The Dissertation contains a theoretical rationale and a practical solution for a pressing scientific problem in the field of medicine - Lung protection during cardiopulmonary bypass in children with congenital heart diseases. The Dissertation is the first national research devoted to the problems of intraoperative lung protection in children with congenital heart diseases, operated with cardiopulmonary bypass. The Dissertation studies and analyzes the causes of pulmonary complications in children during the intraoperative period and at all stages of management. The study materials consisted of 437 patients with congenital heart diseases, aged from birth to three years old, who were operated with cardiopulmonary bypass from 2012 to 2016. The work was carried out in two stages. The first stage of the study identified the risk factors for the pulmonary complications occurrence in the preoperative, intraoperative, and early postoperative periods in 333 patients from the retrospective group (2012-2013). The frequency of the pulmonary complications registration during the standard procedure of intraoperative management has been determined in 66 (19.8%) patients. The prognostic models of significant risk factors for the pulmonary complications detection in the early postoperative period have been built. The fundamental and intraoperative changes in the lung functions (physiological, mechanical and oxygenating) have been revealed. The second stage of the study developed and put into practice a new modified lung protection method in children. The lung protection protocol displayed a model of "physiological lung" preserving the artificial lung ventilation and the pulmonary artery perfusion during a cardioplegic cardiac arrest. The analysis was carried out on 104 patients of the prospective group (2013-2016) wherein the patients' groups were analyzed with the application of different methods of intraoperative management. The operations were carried out using the above modified method protocol in 34 (33%) patients (a study group) while in 70 (67%) patients (a comparison group) a standard protocol was used. According to the gender characteristics, the group included 50 (48%) boys and girls 54 (52%), median age was 10.0 months, interquartile distance [Q25%; Q 75%] from 4 to 17 months. The distribution of age groups was as follows: newborn babies were 10 (9.6%), from one month to one year 56 (53.9%), from one year to three 38 (36.5%), the majority of children 67 (64.4%) was in the age group until the year. Patients in the study and comparison groups did not significantly differ from each other by age, height, and weight (p> 0.05). The Dissertation establishes that the implemented method solves the problem of collapse by preventing a decrease in Cst level at the end of the operation to 0.72 (95% CI 0.63- 0.81) (p = 0.003) and a decrease of OR to 0.81 (95% CI 0, 72 -0.88) (p <0.001) at the time of the congenital defects correction in children. The method decreases the artificial lung ventilation duration in the study group without lung complications in contrast with the comparison group (p <0.001). It also reduces the time spent in the ICU (p <0.001). The Dissertation proves that the modified intraoperative method of lung protection reduces the cytokines growth dynamics during the operation, which in its turn is the evidence for the systemic inflammatory response decrease. Monitoring the cytokines indicators in blood serum allows to predict the possible postoperative complications and choose the further management tactics. The developed method of intraoperative management of patients enables reducing the frequency of the pulmonary complications registration by 8% in the early postoperative period. Improve the mechanical properties of the lungs, reduce the manifestations of systemic and inflammatory response of the body, reduce the duration of mechanical ventilation and stay in ICU. In order to predict the risks of pulmonary complications, a comprehensive assessment of the children condition is required. Which included the main indicators of the cytokine profile (proinflammatory cytokines TNF-?, IL-6 and anti-inflammatory cytokines IL-10) in the diagnostic algorithm are included, as well as the use of a statistical mathematical model for the identification of risk factors and prevention of pulmonary complications.