The effect of noninvasive ventilation with the helmet compared with facial mask in patients with acute respiratory failure: a randomized controlled study

Objective To explore the effect of noninvasive ventilation (NIV) with helmet or facial mask on clinical efficacy, tolerability, and prognosis in patients with acute respiratory failure. Methods Fifty patients with acute respiratory failure according to the inclusion criteria were recruited from January 2018 to July 2018 in Emergency Intensive Care Unit of the First Affiliated Hospital of Zhengzhou University. Included patients were randomly allocated into the helmet group or facial mask group. Based on conventional drug therapy, pressure support mode was performed with the interface of the helmet or facial mask. Oxygenation index, arterial carbon dioxide partial pressure, and respiratory rates were measured before and after the treatment, and the data were compared and analyzed by the repeated measures ANOVA. Tolerance score, complication rate, tracheal intubation rate, and mortality rate were recorded at each observation time point of the two groups. Results The oxygenation index before NIV, at 4 h and at the end of NIV treatment of the helmet group were significantly increased from (160.29±50.32) mmHg to (249.29±83.47) mmHg and (259.24±87.09) mmHg; the oxygenation index of the facial mask group were increased from (168.63±38.63) mmHg to (225.00±74.96) mmHg and (217.69±77.80) mmHg, and there was no significant difference within the two groups (P 0.05). Patients in the helmet was better tolerated than those in the facial mask group [ratio of good tolerance 96% (24/25) vs 56% (14/25) (P = 0.001) and fully tolerance 80% (20/25) vs 36% (9/25) (P =0.002)] and had less complications (1/25 vs 10/25, P = 0.002). 84% patients in the helmet group and 76% patients in the facial mask group were successfully weaned and discharged after NIV treatment (P =0.480). Conclusions Similar clinical efficacy in improving blood gas exchange and relieving dyspnea were observed in the helmet group and the facial mask group in patients with acute respiratory failure. However, the helmet is better tolerant, and had lower complication rate, which is especially suitable for patients with chest trauma combined with facial injuries. Key words: Helmet; Facial mask; Noninvasive ventilation; Acute respiratory failure; Chest trauma; Randomized controlled trial