Inclusion Criteria:  1.Children between 29 days and 18 years old. 2.Severe pneumonia and/or sepsis.Patients were included who meet the guideline for diagnosis and treatment of community-acquired pneumonia in Children (2019) issued by the National Health Commission of the people's Republic of China and/or who meet the International Guide to the 2020 campaign to Save sepsis: management of septic shock and sepsis-related organ dysfunction in children.  Exclusion Criteria:  1.notifiable infectious diseases. 2.The researcher believes that he is not suitable to participate in other situations in this study. 3.Participants in other clinical trials in the same period. 4. discharge within 48 hours