Etiological structure, peculiarities of course and therapy of acute bronchiolitis in children of high-risk groups of severe course

Acute bronchiolitis (AB) is an inflammatory disease of the bronchioles in children in the first two years of life, most commonly occurring in children in the first six months. Preterm infants, children with congenital heart disease (CHD), bronchopulmonary dysplasia (BPD) and other chronic diseases are at high risk of severe acute bronchiolitis. Respiratory syncytial virus (RSV) is the leading etiological factor causing severe ED in these patients. Objective. To establish the etiological structure, clinical features and describe the therapy of severe AB in children at risk. Patients and methods. The study included 35 children of the first two years of life hospitalised in the intensive care unit (ICU) with a diagnosis of AB. Patients were divided into two groups: a group with risk factors for severe AB (n = 17) and a group without risk factors (n = 18). Risk factors included age less than 3 months (n = 8), prematurity (n = 7), ALD (n = 5), CHD (n = 4), Down syndrome (n = 1), and multiple CHD (n = 1). Disease etiology was determined using polymerase chain reaction from nasopharyngeal aspirate. Aetiology, clinical features, SpO2/FiO2 ratio, Paediatric Early Warning Scale (PEWS), Paediatric Organ Dysfunction Scale (pSOFA) and Modified Wood's Clinical Asthma Assessment Scale (mWCAS) scores, complications, outcomes and frequency of different therapies depending on the presence/absence of risk factors for severe AB were analysed. Results. In the group of patients with risk factors, infection due to RSV was predominant and was detected in 8 (47%) of 17 children, whereas in the group without risk factors, RSV was detected in only 2 of 18 (11%) children (p = 0.027). In the group with risk factors for severe AB, the mean age was 2.0 months [1.0; 4.0], while in the group without risk factors it was 6.0 [3.0; 12.0] months (p = 0.019). The duration of hospitalisation in the ICU was significantly longer in children with risk factors for severe AB, 4.0 [3.0; 9.0] days versus 2.5 [2.0; 3.75] days in the group without risk factors (p = 0.017). The SpO2/FiO2 ratio was significantly lower in patients with risk factors, being 238.0 [203.27; 260.0], compared with 280.0 [272.5; 340.0] in the group without risk factors (p < 0.001). The mean PEWS score was higher in at-risk children, 7.0 [5.0; 8.0] versus 5.0 [4.0; 7.0] in the group without risk factors (p = 0.037). The pSOFA score also showed higher values in the group with risk factors (2.0 [1.0; 3.0] vs. 1.0 [0.5; 1.0], p = 0.007). Similar differences were found on the mWCAS scale: 5.36 [4.75; 8.0] points in the group of OB patients with risk factors versus 4.0 [3.0; 4.6] points in the group without risk factors (p = 0.004). Complications of AB were significantly more frequent in the group of patients with risk factors: 9 of 17 children (53%) versus 3 of 18 children (17%) in the group without risk factors (p = 0.035) and included pneumonia and acute respiratory distress syndrome. There was one fatality in the group with risk factors. Oxygen therapy via nasal cannula or face mask was used less frequently in the group of children with risk factors (29% vs 67% of children in the group without risk factors, p = 0.044). The need for ventilatory support was significantly higher in the group with risk factors (6 of 17 children, 35%) compared to the group without factors, where this method was used in only one child (6%, p = 0.041). Antibiotic therapy was used more frequently in the group of children with risk factors, in 10 of 17 children (59%) compared to 4 of 18 children (22%) in the group without risk factors (p = 0.041). Haemotransfusions were required in 6 children in the group of patients with risk factors (35%), whereas they were not performed in the group without risk factors (p = 0.008). Conclusion. Children at risk of severe AB require more intensive treatment, including a higher need for respiratory support and antibiotic therapy. RSV remains the most frequent, preventable by passive immunoprophylaxis, etiological factor in severe AB. © 2024, Dynasty Publishing House. All rights reserved.