Helmet May Be Better Than Facemask in CPAP for COVID-19 Respiratory Failure

CPAP machine
CPAP machine
How does use of a helmet vs facemask for CPAP affect rates of survival and intubation in patients with acute hypoxemic respiratory failure due to COVID-19?

Continuous positive airway pressure (CPAP) delivered with a helmet interface, rather than a facemask, may prevent endotracheal intubation in patients with COVID-19 and moderate-to-severe respiratory failure, researchers reported in Chest.

The prospective, single-center, cohort study compared clinical outcomes in patients with acute hypoxemic respiratory failure due to COVID-19 who received CPAP via helmet vs facemask.

The study involved 112 patients with COVID-19 respiratory failure who were admitted to the respiratory intermediate care unit of a hospital in Buenos Aires, Argentina, from June 2020 to September 2021. CPAP was delivered via a ventilator with a low-pressure oxygen source, and patients were given the choice of receiving oxygen through a helmet or nonvented oronasal mask with a blue elbow. The oronasal mask involved use of a double-limb circuit with an expiratory valve; the helmet involved use of a single-limb circuit with a positive end expiratory pressure (PEEP) valve on the interface’s exhalation port.

Among those who used the helmet (n=55; median age, 57 years [range, 48-64]; 22% female), the median PaO2/FiO2 when receiving high-flow oxygen before CPAP initiation was 96 mm Hg, compared with101 mm Hg in patients who subsequently received facemask (n=57; median age, 57 years [range, 43-66]; 35% female) (P = .25).

The helmet group had a significantly lower rate of endotracheal intubation compared with the facemask group (29% vs 49%, respectively), with a hazard ratio adjusted for Sequential Organ Failure Assessment score and PaO2/FiO2 at inclusion of 0.47 (95% CI, 0.25-0.87; P =.017). The SpO2/FiO2 ratio during the treatment was higher and the respiratory rate was lower in patients who received helmet CPAP than in those who received facemask CPAP (analysis of variance for repeated measures: P <.05 for both). Notably, a significantly lower incidence of hypoxemia, a cause of endotracheal intubation, was found among patients in the helmet group vs those in the facemask group (5% vs 18%, respectively; P =.005).

The inhospital mortality rate was also lower in the helmet CPAP group compared with the facemask group (18% vs 35%, respectively; adjusted hazard ratio, 0.38; 95% CI, 0.18-0.83; P =.015).

Despite the non-randomized design of this investigation and the small sample analyzed, these findings suggest a possible clinical benefit of helmet over facemask CPAP in patients with COVID-19 respiratory failure,” said the investigators. “Further randomized studies systematically assessing the clinical effects of helmet CPAP in COVID-19 and other hypoxemic patients appear warranted to foster its use in other intensive care units.”

Disclosure: Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Colaianni-Alfonso N, Montiel GC, Vega ML, Mazzinari G, Alonso-Íñigo JM, Grieco DL. Helmet versus facemask CPAP in COVID-19 respiratory failure: a prospective cohort study. Chest. Published online August 29, 2022. doi:10.1016/j.chest.2022.08.2221