Study design
We performed a single-center retrospective chart review in the pediatric emergency department of the Dokuz Eylul University Faculty of Medicine, a tertiary hospital with approximately 120000 pediatric emergency department admissions per annum. The study was approved by the Institutional Review Board of the Dokuz Eylul University Faculty of Medicine (approval number: 2020/01-11).
Children aged between 0 and 18 years who were referred to the pediatric emergency department due to drowning-related pulmonary edema and underwent NIV treatment between May 2014 and October 2020 were included. The International Classification of Diseases (ICD) codes for drowning, near drowning, immersion, and submersion injuries were used to identify patients. We obtained information from a computer database, electronic medical records, medical charts, and nursing records of the cases. Patients were excluded if they had chronic pulmonary, cardiac, or neuromuscular diseases; if they were transferred from another hospital; and if there were insufficient data.
The following data were recorded: demographic data; initial body temperature and Glasgow Coma Scale (GCS) score; heart rate; respiratory rate (RR); peripheral oxygen saturation (SpO₂); blood pressure; fraction of inspired oxygen (FiO₂); SpO₂/FiO₂ (S/F) ratio at 0, 1, 2, 4, 8, and 12 hours; clinical findings; and results of the laboratory and radiologic investigations and applied treatments. Using findings at arrival to the pediatric emergency department, patients were divided into 6 groups using the Szpilman classification system as follows: grade 1, normal pulmonary auscultation with coughing; grade 2, abnormal pulmonary auscultation with rales in some pulmonary fields; grade 3, pulmonary auscultation of acute pulmonary edema without arterial hypotension; grade 4, pulmonary auscultation of acute pulmonary edema with arterial hypotension; grade 5, isolated respiratory arrest; and grade 6, cardiopulmonary arrest ¹³.
Non-invasive ventilation strategies were divided into two groups as continuous (CPAP) or bi-level (BiPAP) positive airway pressure [spontaneous, spontaneous/timed (ST), or timed mode for NIV ventilators (Philips Respironics V60 ventilator, USA); A/C pressure or PSV mode for conventional ventilators with NIV option (Maquet Servo I, Germany)].
The time between arrival to the pediatric emergency department and starting NIV application, total duration time and observed side effects during NIV treatment, need for IMV, need for pediatric intensive care unit (PICU) admission, and total length of stay in the PICU and in the hospital were recorded for each patient.