Predictors of Non-invasive Ventilation Failure and Associated Factors Among the COVID-19 Patients Admitted to Intensive Care Unit.

BACKGROUND: Non-invasive ventilation (NIV) is a method of oxygenation supply that eliminates the need for an endotracheal airway. Non-invasive ventilation failure is defined as the necessity for endotracheal intubation or death during the NIV trial.

OBJECTIVES: This study aimed to identify the predictors and associated factors of NIV failure in coronavirus disease 2019 (COVID-19) patients admitted to an intensive care unit (ICU).

METHODS: This retrospective, longitudinal cohort study utilized electronic medical records of COVID-19 patients admitted to the ICU. A total of 150 patients were included in the study. Patient demographics, medical history, laboratory tests, partial pressure of carbon dioxide (PCO2 ), oxygen saturation (SpO2 ), heart rate, acidosis, consciousness, oxygenation, and respiratory rate (HACOR score), and the ratio of oxygen saturation (ROX) index (the SpO2 /fraction of inspired oxygen [FIO2 ] to respiratory rate [SF] ratio) were recorded. Non-invasive ventilation failure was determined based on the need for endotracheal intubation or cardiac-respiratory arrest while on NIV.

RESULTS: Of 150 patients, 55.3% were male (mean age: 55.9 years), with an NIV failure rate of 67.3%, a mortality rate of 66.7%, and 3.3% of patients requiring tracheostomy after NIV failure. The ROX index consistently decreased over time, and an increase in the HACOR score and PCO2 after 6 hours of commencing NIV were the predictors of NIV failure. Additionally, higher levels of lactate dehydrogenase, lower SF ratios, and higher APACHE scores upon ICU admission were significantly associated with NIV failure. Notably, the erythrocyte sedimentation rate (ESR) as an inflammatory index, SF ratio upon ICU admission, HACOR score, ROX index, and PCO2 after 12 hours were significant predictors of in-hospital mortality in patients receiving NIV.

CONCLUSIONS: The ROX index, HACOR scale, and PCO2 are significant predictors of both NIV failure and in-hospital mortality.