Background: Noninvasive ventilation has emerged as a preferred alternative to invasive mechanical ventilation, offering benefits such as reduced intensive care unit, respiratory center unit stay, lower complication rates, and improved patient outcomes. However, NIV failure, remains a critical concern.

Aim of Work: Identification of the predictors of noninvasive ventilation failure among patients in RCU in Benha University hospital.

Methods: This prospective observational study was conducted to 100 Patients presented with (ARF) and was admitted to (RCU), Chest Department in Benha University Hospitals from June 2022 to June 2023. Patients were divided into two groups: successful NIV (n=63) and failed NIV (n=37).

Results: Significant predictors of NIV failure included higher heart rate, systolic blood pressure, and respiratory rate, along with lower diastolic blood pressure (P < 0.001). Conditions such as chronic obstructive pulmonary disease and pneumonia were more common in the failed NIV group (P < 0.001), while pulmonary edema was more prevalent in the successful NIV group (P < 0.05). Cardiac and renal comorbidities were significantly associated with successful NIV. PaCO2 levels, acute physiology and chronic health evaluation scores were higher in the failed NIV group. Multivariate regression identified weight, body mass index, cardiac and renal comorbidity, acute admissions, APACHE score, and bilevel positive airway pressure use as independent predictors of NIV failure (P < 0.05), while sex was not a significant predictor.

Conclusion: Weight, BMI, cardiac, renal comorbidity, acute admission, APACHE and BiPAP were independent predictors of NIV failure in RCU patients.