Publication

Abstract :

Background

Noninvasive ventilation (NIV) is an established first-line treatment of acute respiratory failure both in emergency departments (ED) and intensive care unit (ICU) settings. It is however not always successful.

Materials and methods

Prospective, observational study was done among patients above 18 years presenting with acute respiratory failure initiated on NIV. Patients were placed in one of two groups covering successful NIV treatment and NIV failure. Two groups were compared on four variables: initial respiratory rate (RR), initial high-sensitivity C-reactive protein (hs-CRP), PaO₂/FiO₂ ratio (p/f ratio), and heart rate, acidosis, consciousness, oxygenation, and respiratory rate (HACOR) score at the end of 1 hour of initiation of NIV.

Results

A total of 104 patients fulfilling the inclusion criteria were included in the study, of which 55 (52.88%) were exclusively treated with NIV (NIV success group), and 49 (47.11%) required endotracheal intubation and mechanical ventilation (NIV failure group). Noninvasive ventilation failure group had a higher mean initial RR compared with NIV success group (40.65 ± 3.88 vs 31.98 ± 3.15, p <0.001). Mean initial PaO₂/FiO₂ ratio was also significantly lower in the NIV failure group (184.57 ± 50.33 vs 277.29 ± 34.70, p <0.001). Odds ratio for successful NIV treatment with a high initial RR was 0.503 (95% confidence interval (CI), 0.390–0.649) and with a higher initial PaO₂/FiO₂ ratio was 1.053 (95% CI: 1.032–1.071 and with a HACOR score of >5 at the end of 1 hour of initiation of NIV was highly associated with NIV failure (p <0.001). A high initial level of hs-CRP was 0.949 (95% CI: 0.927–0.970).

Conclusion

Noninvasive ventilation failure could be predicted with information available at presentation in ED, and unnecessary delay in endotracheal intubation could possibly be prevented.