Differential Diagnosis of Congenital Pneumonia in Newborns with Low and Extremely Low Body Weight (Morphological Study)

Abstract

The purpose of the study is a comprehensive assessment of morphological changes in the placenta and lungs to detect early signs of congenital pneumonia in extremely premature infants.Materials and methods. Protocols of post-mortem examinations of 23 preterm newborns died from severe respiratory failure were analyzed. The average gestational age of the newborns was 26.4±2.7 weeks and the body weight at birth was 972.4±355.8 grams. In the sample, 78.3% of infants had an extremely low birth weight (ELBW). At birth, all newborns presented severe asphyxia. Newborn underwent several types of respiratory therapy since birth: Mechanical ventilation was performed in 65.2% of newborns since their birth, non-invasive ventilation was performed in 26.1% of cases, and 8.7% of patients underwent oxygenotherapy through a facial mask. In all cases, there was an unfavorable course of the neonatal period, a progressive deterioration of newborns' condition, and a lethal outcome. A comprehensive histological examination of the placenta and the lungs of deceased premature newborn infants was performed.Results. Congenital infections of different localizations remain the leading cause of death.Congenital pneumonia and generalized infections are clinically manifested at birth by severe perinatal hypoxia and respiratory failure. In the case of congenital pneumonia, the morphological patterns are polymorphic and characterize the severity of lung damage. For some newborns, these patterns include accumulation of exudates and fibrin, segmented leukocytes, fragments of basophilic coccal microflora, and a large number of colony forming bacilli, and desquamated alveolocytes with a deformed nucleus are visualized in the deformed lumen of the alveoli and bronchi. Diffuse lymphoid-leukocyte infiltration in the septa and respiratory parts of the lungs are typical for other infants. Histological examination find lumpy or lamellar eosinophilic hyaline membranes in alveoli in specimens from these newborns. Diffuse, focal or confluent segmentonuclear infiltration in various lung structures is commonly combined with hyaline membranes of various localizations and sizes. Hyaline membranes were detected in 93.5% of cases.Conclusion. Very early preterm delivery is associated with intrauterine pneumonia and systemic infection in extremely premature infants. Early clinical and laboratory signs of intrauterine infectious lung include severe perinatal hypoxia, very low Apgar score and laboratory test findings (hypoxaemia and decompensated metabolic lactate acidosis) that are resistant to standard resuscitation measures. Hypoxemia and decompensated metabolic acidosis persisting during the first hours of postnatal life indicate the severity of intrauterine lung damage and require a rapid change of treatment aimed at normalization of lung function, prevention of complications in the respiratory system, hemostasis and central nervous system. Clinicians should be better informed about the features of early postnatal adaptation of extremely premature infants with congenital pneumonia to provide appropriate treatment.