Study population
pneumonia, ventilator-associated
MULTIPLE ORGAN FAILURE, PNEUMONIA, DISEASE
This study was conducted at the 14-bed tertiary ICU of Shandong Provincial Hospital Affiliated to Shandong First Medical University, with the biggest cardiac surgery center of Shandong province. To reduce surgical technique bias, we chose the fixed ward with an experienced medical team consisted of six professors, each with experience of 3000 solo operations.Patients who underwent cardiovascular surgery and fulfilled the following criteria were included: (1) less than 6 years old; (2) long-term resident of Jinan city or cities with meteorological air quality index (AQI) within 10% of the Jinan index. The exclusion criteria were: (1) existing pneumonia up to seven days before surgery; (2) multiple organ failure before surgery; (3) administration of endotracheal intubation before surgery.The medical records of 2563 patients, admitted from December 2013 through December 2020, were analyzed for all modes of admission to the ICU. Clinical data were obtained from the patient data management system, while personal information (pervious medical history and history of medication) was extracted from other medical records. After exclusion of patients with more than 10% difference in PMSchematic of patient selection strategy. Notes: ICU: Intensive care unit; VAP: ventilator-associated pneumoniaRelevant demographic and clinical data were obtained for all selected patients. Ventilation duration is the total number of hours that the patient received invasive ventilation during the same ICU admission. ICU stay and postoperative hospital stay were collected by days. To protect patient confidentiality, all records were deidentified before analysis. Quality control and data management were performed by Shandong Centers for Disease Control and Prevention.