Effect of High-Flow Nasal Oxygen vs Standard Oxygen on 28-Day Mortality in Immunocompromised Patients With Acute Respiratory Failure

Importance

High-flow nasal oxygen therapy is increasingly used for acute hypoxemic respiratory failure (AHRF).

Objective

To determine whether high-flow oxygen therapy decreases mortality among immunocompromised patients with AHRF compared with standard oxygen therapy.

Design, Setting, and Participants

The HIGH randomized clinical trial enrolled 776 adult immunocompromised patients with AHRF (Pao₂<60 mm Hg or Spo₂<90% on room air, or tachypnea >30/min or labored breathing or respiratory distress, and need for oxygen ≥6 L/min) at 32 intensive care units (ICUs) in France between May 19, 2016, and December 31, 2017.

Interventions

Patients were randomized 1:1 to continuous high-flow oxygen therapy (n = 388) or to standard oxygen therapy (n = 388).

Main Outcomes and Measures

The primary outcome was day-28 mortality. Secondary outcomes included intubation and mechanical ventilation by day 28, Pao₂:Fio₂ratio over the 3 days after intubation, respiratory rate, ICU and hospital lengths of stay, ICU-acquired infections, and patient comfort and dyspnea.

Results

Of 778 randomized patients (median age, 64 [IQR, 54-71] years; 259 [33.3%] women), 776 (99.7%) completed the trial. At randomization, median respiratory rate was 33/min (IQR, 28-39) vs 32 (IQR, 27-38) and Pao₂:Fio₂was 136 (IQR, 96-187) vs 128 (IQR, 92-164) in the intervention and control groups, respectively. Median SOFA score was 6 (IQR, 4-8) in both groups. Mortality on day 28 was not significantly different between groups (35.6% vs 36.1%; difference, −0.5% [95% CI, −7.3% to +6.3%]; hazard ratio, 0.98 [95% CI, 0.77 to 1.24];P = .94). Intubation rate was not significantly different between groups (38.7% vs 43.8%; difference, −5.1% [95% CI, −12.3% to +2.0%]). Compared with controls, patients randomized to high-flow oxygen therapy had a higher Pao₂:Fio₂(150 vs 119; difference, 19.5 [95% CI, 4.4 to 34.6]) and lower respiratory rate after 6 hours (25/min vs 26/min; difference, −1.8/min [95% CI, −3.2 to −0.2]). No significant difference was observed in ICU length of stay (8 vs 6 days; difference, 0.6 [95% CI, −1.0 to +2.2]), ICU-acquired infections (10.0% vs 10.6%; difference, −0.6% [95% CI, −4.6 to +4.1]), hospital length of stay (24 vs 27 days; difference, −2 days [95% CI, −7.3 to +3.3]), or patient comfort and dyspnea scores.

Conclusions and Relevance

Among critically ill immunocompromised patients with acute respiratory failure, high-flow oxygen therapy did not significantly decrease day-28 mortality compared with standard oxygen therapy.

Trial Registration

clinicaltrials.gov Identifier:NCT02739451.