* at the time of randomization patients requiring icu admission or patients with severe respiratory insufficiency requiring mechanical ventilation or with rapid worsening of respiratory function leading to expectation for mechanical ventilation or icu admission. * evidence of rapid clinical deterioration or existence of any life-threatening co-morbidity or any other medical condition which, in the opinion of the investigator, makes the patient unsuitable for inclusion.

* at the time of randomization patients requiring icu admission or patients with severe respiratory insufficiency requiring mechanical ventilation or with rapid worsening of respiratory function leading to expectation for mechanical ventilation or icu admission. * evidence of rapid clinical deterioration or existence of any life-threatening co-morbidity or any other medical condition which, in the opinion of the investigator, makes the patient unsuitable for inclusion.

- at the time of randomization patients requiring icu admission or patients with severe respiratory insufficiency requiring mechanical ventilation or with rapid worsening of respiratory function leading to expectation for mechanical ventilation or icu admission. - evidence of rapid clinical deterioration or existence of any life-threatening co-morbidity or any other medical condition which, in the opinion of the investigator, makes the patient unsuitable for inclusion.

- at the time of randomization patients requiring icu admission or patients with severe respiratory insufficiency requiring mechanical ventilation or with rapid worsening of respiratory function leading to expectation for mechanical ventilation or icu admission. - evidence of rapid clinical deterioration or existence of any life-threatening co-morbidity or any other medical condition which, in the opinion of the investigator, makes the patient unsuitable for inclusion.