Outcomes
The primary outcome was oxygenation and functional capacity. The secondary was the impact on functional variables such as Functional Independence Measure (FIM), peripheral muscle strength, pulmonary complications, death, length of stay in the ICU and hospital. The primary oxygenation outcome was assessed before, immediately after, and one day after NIV application, functional capacity was assessed preoperatively and on the day of hospital discharge. Secondary outcomes were assessed preoperatively and on the day of hospital discharge.