inclusion criteria: 1. laboratory confirmed severe acute respiratory infection (sari) pneumonitis such as coronavirus disease of 2019 (covid-19) or influenza, and 2. ≥5 days of mechanical ventilation, and 3. moderate to severe respiratory failure as shown by either the ratio of partial pressure of oxygen and the fracture of inspired oxygen (pao2:fio2 rati)o \<150 for \>6 hours or the potential of hydrogen (ph) \<7.30 with carbon dioxide (co2) \>50mmhg for 6 hours, and 4. are unable to pass a spontaneous breathing trial.

inclusion criteria: 1. laboratory confirmed severe acute respiratory infection (sari) pneumonitis such as coronavirus disease of 2019 (covid-19) or influenza, and 2. ≥5 days of mechanical ventilation, and 3. moderate to severe respiratory failure as shown by either the ratio of partial pressure of oxygen and the fracture of inspired oxygen (pao2:fio2 rati)o \<150 for \>6 hours or the potential of hydrogen (ph) \<7.30 with carbon dioxide (co2) \>50mmhg for 6 hours, and 4. are unable to pass a spontaneous breathing trial.

inclusion criteria: laboratory confirmed severe acute respiratory infection (sari) pneumonitis such as coronavirus disease of 2019 (covid-19) or influenza, and ≥5 days of mechanical ventilation, and moderate to severe respiratory failure as shown by either the ratio of partial pressure of oxygen and the fracture of inspired oxygen (pao2:fio2 rati)o <150 for >6 hours or the potential of hydrogen (ph) <7.30 with carbon dioxide (co2) >50mmhg for 6 hours, and are unable to pass a spontaneous breathing trial.

inclusion criteria: laboratory confirmed severe acute respiratory infection (sari) pneumonitis such as coronavirus disease of 2019 (covid-19) or influenza, and ≥5 days of mechanical ventilation, and moderate to severe respiratory failure as shown by either the ratio of partial pressure of oxygen and the fracture of inspired oxygen (pao2:fio2 rati)o <150 for >6 hours or the potential of hydrogen (ph) <7.30 with carbon dioxide (co2) >50mmhg for 6 hours, and are unable to pass a spontaneous breathing trial.

inclusion criteria: 1. laboratory confirmed severe acute respiratory infection (sari) pneumonitis such as coronavirus disease of 2019 (covid-19) or influenza, and 2. ≥5 days of mechanical ventilation, and 3. moderate to severe respiratory failure as shown by either the ratio of partial pressure of oxygen and the fracture of inspired oxygen (pao2:fio2 rati)o <150 for >6 hours or the potential of hydrogen (ph) <7.30 with carbon dioxide (co2) >50mmhg for 6 hours, and 4. are unable to pass a spontaneous breathing trial.

inclusion criteria: 1. laboratory confirmed severe acute respiratory infection (sari) pneumonitis such as coronavirus disease of 2019 (covid-19) or influenza, and 2. ≥5 days of mechanical ventilation, and 3. moderate to severe respiratory failure as shown by either the ratio of partial pressure of oxygen and the fracture of inspired oxygen (pao2:fio2 rati)o <150 for >6 hours or the potential of hydrogen (ph) <7.30 with carbon dioxide (co2) >50mmhg for 6 hours, and 4. are unable to pass a spontaneous breathing trial.