Effects of 45° prone position ventilation in the treatment of acute respiratory distress syndrome: A protocol for a randomized controlled trial study.

Background: Acute respiratory distress syndrome (ARDS) is an increasingly common acute respiratory failure that seriously threaten people's health. ARDS has a case fatality rate of up to 40%. ARDS is a serious threat to the life safety of patients and the quality of life, causing a huge economic burden to individuals, families and society.