group 1 (covid-19 early pneumonia) * concomitant chronic pulmonary disease * chronic heart failure new york heart association (nyha) 3-4 * bacterial pulmonary associated infection (diagnosed or suspected) * pulmonary embolism * acute cardiogenic pulmonary edema * signs of severity with cpap 10 cmh2o and fio2 0.5: spo2≤ 93% associated to either: * dyspnea * two or more signs of increased respiratory effort (respiratory rate ≥25 bpm, use of accessory inspiratory muscles , tirage, intercostal space depression, nasal flaring, expiratory abdominal efforts, paco2 \< 35) * at least one sign of respiratory fatigue/decompensation (ph\<7.30 with paco2 \>45, respiratory rate \<15 bpm, paradoxal abdominal breathing, mental status alteration) group 2 (covid-19 severe pneumonia) * concomitant chronic pulmonary disease * chronic heart failure nyha 3-4 * bacterial pulmonary associated infection (diagnosed or suspected) * pulmonary embolism * acute cardiogenic pulmonary edema * at least one sign of respiratory fatigue/decompensation (ph\<7.30 with paco2 \>45, respiratory rate \<15 bpm, paradoxal abdominal breathing, mental status alteration) group 3 (non covid-19 pneumonia) * concomitant chronic pulmonary disease * chronic heart failure nyha 3-4 * bacterial pulmonary associated infection (diagnosed or suspected) * pulmonary embolism * acute cardiogenic pulmonary edema * at least one sign of respiratory fatigue/decompensation (ph\<7.30 with paco2 \>45, respiratory rate \<15 bpm, paradoxal abdominal breathing, mental status alteration)

group 1 (covid-19 early pneumonia) * concomitant chronic pulmonary disease * chronic heart failure new york heart association (nyha) 3-4 * bacterial pulmonary associated infection (diagnosed or suspected) * pulmonary embolism * acute cardiogenic pulmonary edema * signs of severity with cpap 10 cmh2o and fio2 0.5: spo2≤ 93% associated to either: * dyspnea * two or more signs of increased respiratory effort (respiratory rate ≥25 bpm, use of accessory inspiratory muscles , tirage, intercostal space depression, nasal flaring, expiratory abdominal efforts, paco2 \< 35) * at least one sign of respiratory fatigue/decompensation (ph\<7.30 with paco2 \>45, respiratory rate \<15 bpm, paradoxal abdominal breathing, mental status alteration) group 2 (covid-19 severe pneumonia) * concomitant chronic pulmonary disease * chronic heart failure nyha 3-4 * bacterial pulmonary associated infection (diagnosed or suspected) * pulmonary embolism * acute cardiogenic pulmonary edema * at least one sign of respiratory fatigue/decompensation (ph\<7.30 with paco2 \>45, respiratory rate \<15 bpm, paradoxal abdominal breathing, mental status alteration) group 3 (non covid-19 pneumonia) * concomitant chronic pulmonary disease * chronic heart failure nyha 3-4 * bacterial pulmonary associated infection (diagnosed or suspected) * pulmonary embolism * acute cardiogenic pulmonary edema * at least one sign of respiratory fatigue/decompensation (ph\<7.30 with paco2 \>45, respiratory rate \<15 bpm, paradoxal abdominal breathing, mental status alteration)

group 1 (covid-19 early pneumonia) - concomitant chronic pulmonary disease - chronic heart failure new york heart association (nyha) 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - signs of severity with cpap 10 cmh2o and fio2 0.5: spo2≤ 93% associated to either: - dyspnea - two or more signs of increased respiratory effort (respiratory rate ≥25 bpm, use of accessory inspiratory muscles , tirage, intercostal space depression, nasal flaring, expiratory abdominal efforts, paco2 < 35) - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration) group 2 (covid-19 severe pneumonia) - concomitant chronic pulmonary disease - chronic heart failure nyha 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration) group 3 (non covid-19 pneumonia) - concomitant chronic pulmonary disease - chronic heart failure nyha 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration)

group 1 (covid-19 early pneumonia) - concomitant chronic pulmonary disease - chronic heart failure new york heart association (nyha) 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - signs of severity with cpap 10 cmh2o and fio2 0.5: spo2≤ 93% associated to either: - dyspnea - two or more signs of increased respiratory effort (respiratory rate ≥25 bpm, use of accessory inspiratory muscles , tirage, intercostal space depression, nasal flaring, expiratory abdominal efforts, paco2 < 35) - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration) group 2 (covid-19 severe pneumonia) - concomitant chronic pulmonary disease - chronic heart failure nyha 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration) group 3 (non covid-19 pneumonia) - concomitant chronic pulmonary disease - chronic heart failure nyha 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration)

group 1 (covid-19 early pneumonia) - concomitant chronic pulmonary disease - chronic heart failure nyha 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - signs of severity with cpap 10 cmh2o and fio2 0.5: spo2≤ 93% associated to either: - dyspnea - two or more signs of increased respiratory effort (respiratory rate ≥25 bpm, use of accessory inspiratory muscles , tirage, intercostal space depression, nasal flaring, expiratory abdominal efforts, paco2 < 35) - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration) group 2 (covid-19 severe pneumonia) - concomitant chronic pulmonary disease - chronic heart failure nyha 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration) group 3 (non covid-19 pneumonia) - concomitant chronic pulmonary disease - chronic heart failure nyha 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration)

group 1 (covid-19 early pneumonia) - concomitant chronic pulmonary disease - chronic heart failure nyha 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - signs of severity with cpap 10 cmh2o and fio2 0.5: spo2≤ 93% associated to either: - dyspnea - two or more signs of increased respiratory effort (respiratory rate ≥25 bpm, use of accessory inspiratory muscles , tirage, intercostal space depression, nasal flaring, expiratory abdominal efforts, paco2 < 35) - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration) group 2 (covid-19 severe pneumonia) - concomitant chronic pulmonary disease - chronic heart failure nyha 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration) group 3 (non covid-19 pneumonia) - concomitant chronic pulmonary disease - chronic heart failure nyha 3-4 - bacterial pulmonary associated infection (diagnosed or suspected) - pulmonary embolism - acute cardiogenic pulmonary edema - at least one sign of respiratory fatigue/decompensation (ph<7.30 with paco2 >45, respiratory rate <15 bpm, paradoxal abdominal breathing, mental status alteration)