- age <18 - uncooperative or likely to be unable to lie on abdomen for 16 hours - receiving comfort care only - multi-organ failure - rr>40 - contraindication to pp (e.g. vomiting, abdominal wound, unstable pelvic/spinal lesions, pregnancy >20/40 gestation, severe brain injury).

- age <18 - uncooperative or likely to be unable to lie on abdomen for 16 hours - receiving comfort care only - multi-organ failure - rr>40 - contraindication to pp (e.g. vomiting, abdominal wound, unstable pelvic/spinal lesions, pregnancy >20/40 gestation, severe brain injury).