Mortality risk factors in children with severe influenza virus infection admitted to the pediatric intensive care unit

Some children hospitalized for severe influenza virus infection require intensive care or die because of disease progression, which may be combined with other complications. The objective of this study was to identify the mortality risk factors in the patients with severe influenza virus infection admitted to the pediatric intensive care unit (PICU). Seventy-seven pediatric patients with severe influenza virus infection who were admitted in the PICU at Guangzhou Women and Children's Medical Center between 2013 and 2017 were evaluated. Data were transcribed and analyzed. The patients’ median age was 3.0 years (interquartile range, 1.0–4.0 years), with 59.7% of the patients aged <3 years. The mortality was 16.9%, and patients aged >3 years accounted for 69.2% of the cases. Influenza A virus infection was found in 83.1% of the patients. Coinfection was detected in 58.7% of the patients. Haemophilus influenzae (11.7%) and adenovirus (9.1%) were the predominant bacterial and viral pathogens isolated, respectively. Older age, oxygen saturation level of <90% at admission, acute respiratory distress syndrome, pneumorrhagia, influenza-associated encephalopathy (IEA), septic shock, low ratio of partial pressure of oxygen in arterial blood (PaO(2), <60 mm Hg) to the fraction concentration of oxygen in inspired air (FiO(2); P/F), higher oxygenation index, increased alanine aminotransferase level (>100 IU/L), increased aspartate aminotransferase level (>100 IU/L), increased lactate dehydrogenase level (>500 IU/L), high fraction concentration of oxygen in inspired air (FiO(2) > 60%), and positive end-expiratory pressure (>8 cmH(2)O) were associated with poor outcome. The deceased patients were more likely to have oxygen saturation levels of <90% at admission and IEA than those who survived. Higher P/F ratio was a protective factor against death in patients. The children with severe influenza virus infection who were admitted in the PICU were mainly aged <3 years. The presence of an oxygen saturation level of <90% at admission and IEA were the prognostic variables independently associated with mortality. Higher P/F ratio was a protective factor against death in patients.