Effect of Helmet Noninvasive Ventilation vs High-Flow Nasal Oxygen on Days Free of Respiratory Support in Patients With COVID-19 and Moderate to Severe Hypoxemic Respiratory Failure

Abstract

for the COVID-ICU Gemelli Study Group IMPORTANCE High-flow nasal oxygen is recommended as initial treatment for acute hypoxemic respiratory failure and is widely applied in patients with COVID-19.OBJECTIVE To assess whether helmet noninvasive ventilation can increase the days free of respiratory support in patients with COVID-19 compared with high-flow nasal oxygen alone. DESIGN, SETTING, AND PARTICIPANTSMulticenter randomized clinical trial in 4 intensive care units (ICUs) in Italy between October and December 2020, end of follow-up February 11, 2021, including 109 patients with COVID-19 and moderate to severe hypoxemic respiratory failure (ratio of partial pressure of arterial oxygen to fraction of inspired oxygen Յ200).INTERVENTIONS Participants were randomly assigned to receive continuous treatment with helmet noninvasive ventilation (positive end-expiratory pressure, 10-12 cm H 2 O; pressure support, 10-12 cm H 2 O) for at least 48 hours eventually followed by high-flow nasal oxygen (n = 54) or high-flow oxygen alone (60 L/min) (n = 55). MAIN OUTCOMES AND MEASURESThe primary outcome was the number of days free of respiratory support within 28 days after enrollment. Secondary outcomes included the proportion of patients who required endotracheal intubation within 28 days from study enrollment, the number of days free of invasive mechanical ventilation at day 28, the number of days free of invasive mechanical ventilation at day 60, in-ICU mortality, in-hospital mortality, 28-day mortality, 60-day mortality, ICU length of stay, and hospital length of stay. RESULTS Among 110 patients who were randomized, 109 (99%) completed the trial (median age, 65 years [interquartile range {IQR}, 55-70]; 21 women [19%]). The median days free of respiratory support within 28 days after randomization were 20 (IQR, 0-25) in the helmet group and 18 (IQR, 0-22) in the high-flow nasal oxygen group, a difference that was not statistically significant (mean difference, 2 days [95% CI, −2 to 6]; P = .26). Of 9 prespecified secondary outcomes reported, 7 showed no significant difference. The rate of endotracheal intubation was significantly lower in the helmet group than in the high-flow nasal oxygen group (30% vs 51%; difference, −21% [95% CI, −38% to −3%]; P = .03). The median number of days free of invasive mechanical ventilation within 28 days was significantly higher in the helmet group than in the high-flow nasal oxygen group (28 [IQR,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] vs 25 ; mean difference, 3 days [95% CI, 0-7]; P = .04). The rate of in-hospital mortality was 24% in the helmet group and 25% in the high-flow nasal oxygen group (absolute difference, −1% [95% CI, −17% to 15%]; P > .99).CONCLUSIONS AND RELEVANCE Among patients with COVID-19 and moderate to severe hypoxemia, treatment with helmet noninvasive ventilation, compared with high-flow nasal oxygen, resulted in no significant difference in the number of days free of respiratory support within 28 days. Further research is warranted to determine...

Effects of non-invasive respiratory support on gas exchange and outcomes in COVID-19 outside the ICU

“…WHO COVID-19 guidelines recommend CPAP in ‘selected patients’, however selection criteria are not defined [ 8 ]. RCT data suggest that non-invasive PEEP may reduce risk of IMV [ 9 ]. Though unlikely to modify the disease course, this may allow time for recovery to occur and aid resource allocation.…”

Long-Term Survival of Mechanically Ventilated Patients with Severe COVID-19: An Observational Cohort Study

“…Unfortunately, monitoring of respiratory parameters during sessions was not performed due to the overwhelmed healthcare resources consumption during the pandemic. Helmet noninvasive ventilation has been evaluated as an alternative for the noninvasive respiratory support of patients with hypoxemia with promising results in severe patients with COVID-19, but not found signi cant difference in the number of days free of respiratory support (33). Hence, monitoring of patients receiving noninvasive respiratory support during AHRF remains of paramount importance not to delay endotracheal intubation.…”

What is the most adequate non-invasive oxygen support for acute hypoxaemic respiratory failure due to COVID-19?

“…However, patients having COVID-19-induced respiratory failure present with a remarkable disconnect in rest between profound hypoxaemia yet without proportional signs of respiratory distress, no sensation of dyspnoea or increased respiratory work, and rapid deterioration can occur. This can be illustrated by the comparison between patient population having acute hypoxaemic respiratory failure mainly caused by bacterial pneumonia ( 9 ) and with COVID-19 induced respiratory failure ( 10 ). Despite similar intubation rates, 38 and 34%, respectively in the two populations, PaO 2 /FiO 2 ratio at enrolment in non-COVID-19 patients was higher, 150-160 mm Hg, higher respiratory rate approximating 33 breaths/min, while patients with COVID-19 had a more severe oxygen impairment, PaO 2 /FiO 2 ratio of 102-105 mm Hg, with surprisingly less tachypnoea, and a respiratory rate of 28 breaths/min ( [9] , [10] ).…”

“…This can be illustrated by the comparison between patient population having acute hypoxaemic respiratory failure mainly caused by bacterial pneumonia ( 9 ) and with COVID-19 induced respiratory failure ( 10 ). Despite similar intubation rates, 38 and 34%, respectively in the two populations, PaO 2 /FiO 2 ratio at enrolment in non-COVID-19 patients was higher, 150-160 mm Hg, higher respiratory rate approximating 33 breaths/min, while patients with COVID-19 had a more severe oxygen impairment, PaO 2 /FiO 2 ratio of 102-105 mm Hg, with surprisingly less tachypnoea, and a respiratory rate of 28 breaths/min ( [9] , [10] ). This particular pattern of acute hypoxaemic respiratory failure caused by COVID-19 refers to the concept of “silent” or “happy” hypoxaemia ( [11] , [12] ).…”

“…This raises the questions of whether NIV could be delivered protectively to avoid VILI, and early to improve oxygenation in the management of COVID-19-induced respiratory failure. In patients with COVID-19-induced respiratory failure, helmet NIV delivered with high PEEP, around 12 cm of water has been shown to reduce intubation rates and increase 28-day invasive ventilation-free days as compared to HFNC ( 10 ). However, this trial did not show any difference in mortality rates between the two strategies; in fact, the mortality rate was higher in patients who failed helmet NIV as compared those who failed HFNC.…”