Clinical Profile and Etiological Structure of Diseases in Children with Septic and Critical Conditions Hospitalized in a Pediatric Intensive Care Unit in Bulgaria: A Single-Center Study

Introduction: The history of sepsis dates back to ancient Greece, with its name being derived from the Greek word sepo, meaning decay. A large multicentered study conducted in 2020 reported that sepsis accounts for 48.9 million cases annually, resulting in over 11 million fatalities. Strengthening prevention, early diagnosis, and appropriate treatment of sepsis remains a primary strategy and objective of the World Health Organization, as outlined in the resolutions of the Seventeenth World Health Assembly. Aim: The aim of this article is to investigate the clinical profile and etiological structure of diseases in children with septic and critical conditions hospitalized between June 2022 and January 2024 in the pediatric intensive care unit of a Bulgarian university hospital. Materials and Methods: Over an 18-month prospective period, a total of 53 children, aged from 7 days to 18 years, with acute-onset infectious diseases or in critical conditions meeting predefined inclusion criteria were evaluated. For the purposes of the study, medical history, physical examination, and laboratory methods to determine complete blood count, blood gas analysis, coagulation and biochemical parameters, and microbiological analysis of blood were used. Results: The relative share of children with diseases of infectious etiology was 79.2% (septic group), while those with non-infectious critical conditions accounted for 20.8%. The 13–48-month age group represented the highest relative proportion of hospitalizations (30.2%). Lower respiratory tract infections dominated in the septic group (53.4%), while intoxications were the leading cause in the critical condition group (36.4%). Microbiological identification was achieved in 42.8% of infections, with bacterial pathogens predominating over viral ones (55.6% vs. 44.4%). Escherichia coli, Streptococcus pneumoniae, and Staphylococcus aureus were among the bacterial species most frequently identified as causative agents of infections, associated with sepsis. Long-term complications following intensive treatment were observed in 9.4%. Conclusion: Knowledge about the microbial spectrum of sepsis in childhood allows applying etiological rather than empirical antibiotic therapy, and the modern diagnostic methods ensure its timely initiation and reduction of the long-term disability risk.