1. immediate need for intubation as determined by the treating team. 2. decreased level of consciousness (glasgow coma scale score \<10), or significant cognitive impairment hat may interfere with compliance (delirium, dementia) 3. contraindication to proning including, but not limited to any of the following: open chest or abdomen, abdominal surgery (i.e. laparotomy) within the 4 days, unstable spine, facial, cervical, femur, or pelvic fractures. limited neck mobility or inability to lie prone comfortably skeletal deformities that interfere with proning. complete bowel obstruction. active upper gastrointestinal bleeding. patient is unlikely/unable to prone, or to be compliant as indicated by the treating team. 4. body mass index \> 40 kg/m2 5. pregnancy - third trimester. 6. patient/substitute decision maker or caring physician's refusal to enroll in the study. 7. patients with hemodynamic instability and moderate to high dose of vasopressors (norepinephrine dose ≥ 0.15 mcg/kg/min) 8. intubation is not within patient's goals of care 9. patient received awake proning session for \> 1 day prior to randomization 10. previous intubation within the same hospital admission

1. immediate need for intubation as determined by the treating team. 2. decreased level of consciousness (glasgow coma scale score \<10), or significant cognitive impairment hat may interfere with compliance (delirium, dementia) 3. contraindication to proning including, but not limited to any of the following: open chest or abdomen, abdominal surgery (i.e. laparotomy) within the 4 days, unstable spine, facial, cervical, femur, or pelvic fractures. limited neck mobility or inability to lie prone comfortably skeletal deformities that interfere with proning. complete bowel obstruction. active upper gastrointestinal bleeding. patient is unlikely/unable to prone, or to be compliant as indicated by the treating team. 4. body mass index \> 40 kg/m2 5. pregnancy - third trimester. 6. patient/substitute decision maker or caring physician's refusal to enroll in the study. 7. patients with hemodynamic instability and moderate to high dose of vasopressors (norepinephrine dose ≥ 0.15 mcg/kg/min) 8. intubation is not within patient's goals of care 9. patient received awake proning session for \> 1 day prior to randomization 10. previous intubation within the same hospital admission

immediate need for intubation as determined by the treating team. decreased level of consciousness (glasgow coma scale score <10), or significant cognitive impairment hat may interfere with compliance (delirium, dementia) contraindication to proning including, but not limited to any of the following: open chest or abdomen, abdominal surgery (i.e. laparotomy) within the 4 days, unstable spine, facial, cervical, femur, or pelvic fractures. limited neck mobility or inability to lie prone comfortably skeletal deformities that interfere with proning. complete bowel obstruction. active upper gastrointestinal bleeding. patient is unlikely/unable to prone, or to be compliant as indicated by the treating team. body mass index > 40 kg/m2 pregnancy - third trimester. patient/substitute decision maker or caring physician's refusal to enroll in the study. patients with hemodynamic instability and moderate to high dose of vasopressors (norepinephrine dose ≥ 0.15 mcg/kg/min) intubation is not within patient's goals of care patient received awake proning session for > 1 day prior to randomization previous intubation within the same hospital admission

immediate need for intubation as determined by the treating team. decreased level of consciousness (glasgow coma scale score <10), or significant cognitive impairment hat may interfere with compliance (delirium, dementia) contraindication to proning including, but not limited to any of the following: open chest or abdomen, abdominal surgery (i.e. laparotomy) within the 4 days, unstable spine, facial, cervical, femur, or pelvic fractures. limited neck mobility or inability to lie prone comfortably skeletal deformities that interfere with proning. complete bowel obstruction. active upper gastrointestinal bleeding. patient is unlikely/unable to prone, or to be compliant as indicated by the treating team. body mass index > 40 kg/m2 pregnancy - third trimester. patient/substitute decision maker or caring physician's refusal to enroll in the study. patients with hemodynamic instability and moderate to high dose of vasopressors (norepinephrine dose ≥ 0.15 mcg/kg/min) intubation is not within patient's goals of care patient received awake proning session for > 1 day prior to randomization previous intubation within the same hospital admission

1. immediate need for intubation as determined by the treating team. 2. decreased level of consciousness (glasgow coma scale score <10), or significant cognitive impairment hat may interfere with compliance (delirium, dementia) 3. contraindication to proning including, but not limited to any of the following: open chest or abdomen, abdominal surgery (i.e. laparotomy) within the 4 days, unstable spine, facial, cervical, femur, or pelvic fractures. limited neck mobility or inability to lie prone comfortably skeletal deformities that interfere with proning. complete bowel obstruction. active upper gastrointestinal bleeding. patient is unlikely/unable to prone, or to be compliant as indicated by the treating team. 4. body mass index > 40 kg/m2 5. pregnancy - third trimester. 6. patient/substitute decision maker or caring physician's refusal to enroll in the study. 7. patients with hemodynamic instability and moderate to high dose of vasopressors (norepinephrine dose ≥ 0.15 mcg/kg/min) 8. intubation is not within patient's goals of care 9. patient received awake proning session for > 1 day prior to randomization 10. previous intubation within the same hospital admission

1. immediate need for intubation as determined by the treating team. 2. decreased level of consciousness (glasgow coma scale score <10), or significant cognitive impairment hat may interfere with compliance (delirium, dementia) 3. contraindication to proning including, but not limited to any of the following: open chest or abdomen, abdominal surgery (i.e. laparotomy) within the 4 days, unstable spine, facial, cervical, femur, or pelvic fractures. limited neck mobility or inability to lie prone comfortably skeletal deformities that interfere with proning. complete bowel obstruction. active upper gastrointestinal bleeding. patient is unlikely/unable to prone, or to be compliant as indicated by the treating team. 4. body mass index > 40 kg/m2 5. pregnancy - third trimester. 6. patient/substitute decision maker or caring physician's refusal to enroll in the study. 7. patients with hemodynamic instability and moderate to high dose of vasopressors (norepinephrine dose ≥ 0.15 mcg/kg/min) 8. intubation is not within patient's goals of care 9. patient received awake proning session for > 1 day prior to randomization 10. previous intubation within the same hospital admission

immediate need for intubation as determined by the treating team. glasgow coma scale score <10 contraindication to proning including any of the following: open chest or abdomen, abdominal surgery (i.e. laparotomy) within the 4 days, or facial, pelvic or cervical spine fractures or instability. patient/substitute decision maker (sdm) or caring physician's refusal to enroll in the study. patients with hemodynamic instability and moderate to high dose of vasopressors (norepinephrine dose ≥ 0.15 mcg/kg/min) body mass index (bmi) > 40 kg/m2. skeletal deformities that interfere with proning such as severe kyphoscoliosis and severe limb contractures.

immediate need for intubation as determined by the treating team. glasgow coma scale score <10 contraindication to proning including any of the following: open chest or abdomen, abdominal surgery (i.e. laparotomy) within the 4 days, or facial, pelvic or cervical spine fractures or instability. patient/substitute decision maker (sdm) or caring physician's refusal to enroll in the study. patients with hemodynamic instability and moderate to high dose of vasopressors (norepinephrine dose ≥ 0.15 mcg/kg/min) body mass index (bmi) > 40 kg/m2. skeletal deformities that interfere with proning such as severe kyphoscoliosis and severe limb contractures.