Safe spontaneous breathing with helmet noninvasive ventilation in acute hypoxemic respiratory failure

Helmet noninvasive ventilation (NIV) has gained attention for the management of hypoxemic patients, owing to physiological and potential clinical benefits. We summarize the recent advances on the topic.

Compared to facemasks, helmets facilitate application of higher positive end-expiratory pressure (PEEP) for prolonged treatments: this improves oxygenation and may mitigate injurious inflation patterns related to lung heterogeneity. The large, highly compliant interface reduces ventilator triggering performance, causing pressure support to be partially out of phase with patient's inspiratory effort; however, it allows patients to breathe from the internal air reservoir, resulting in formally asynchronous breaths that may help attenuate surges in lung stress and tidal volume without causing flow starvation. Through physiological monitoring, ventilator settings can be individualized to modulate inspiratory effort while limiting increases in dynamic transpulmonary driving pressure and tidal volume.

Helmet NIV may offer a valuable strategy for noninvasive management of hypoxemic patients, particularly when applied early, for prolonged periods, and with settings aimed at minimizing injurious inflation in moderate-to-severe (PaO 2 /FiO 2 < 200 mmHg) cases. Interface peculiarities affecting patient-ventilator interaction may constitute key differences with facemask NIV for prevention of injurious inflation patterns. Ongoing trials will clarify whether these physiological advantages improve clinical outcomes.