- icu admission on arrival - respiratory distress requiring immediate intubation - respiratory rate(rr)>35/min, accessory respiratory muscle use (ex. speaking in short sentences), signs of respiratory muscle fatigue, altered mental status, or inability to protect airway - chest or facial trauma, pneumothorax or other contraindication to prone positioning (i.e., spinal instability, recent abdominal surgery, pregnancy, etc) - hemodynamically unstable - heart rate (hr)>120 bpm, systolic blood pressure (sbp)<90 mmhg, mean arterial pressure (map)<65 mmhg or requirement for vasopressor - nausea and vomiting - pregnancy - refusal or inability to tolerate initial prone positioning due to comfort

- icu admission on arrival - respiratory distress requiring immediate intubation - respiratory rate(rr)>35/min, accessory respiratory muscle use (ex. speaking in short sentences), signs of respiratory muscle fatigue, altered mental status, or inability to protect airway - chest or facial trauma, pneumothorax or other contraindication to prone positioning (i.e., spinal instability, recent abdominal surgery, pregnancy, etc) - hemodynamically unstable - heart rate (hr)>120 bpm, systolic blood pressure (sbp)<90 mmhg, mean arterial pressure (map)<65 mmhg or requirement for vasopressor - nausea and vomiting - pregnancy - refusal or inability to tolerate initial prone positioning due to comfort