Lower oxygenation target linked to more days without life support in COVID-19

Key takeaways:

• The lower vs. higher oxygenation target group had a higher median number of days alive without life support.
• Mortality did not significantly differ between the groups.

A 60 mm Hg vs. 90 mm Hg oxygenation target helped adult ICU patients with COVID-19 and severe hypoxemia spend more days alive without life support, according to results published in JAMA.

“More days alive without life support with the lower oxygenation target were similarly observed in the subgroup analysis of patients with COVID-19 in the HOT-ICU trial during the first wave of the pandemic in the spring of 2020, and the current trial supports these findings,” Frederik M. Nielsen, MD, of the department of anesthesia and intensive care at Aalborg University Hospital in Denmark, and colleagues wrote.

In a multicenter randomized clinical trial (HOT-COVID), Nielsen and colleagues analyzed 726 ICU patients (median age, 66 years; 68% men) with COVID-19 and severe hypoxemia between August 2020 and March 2023 to determine if a higher (90 mm Hg) or lower (60 mm Hg) partial pressure of oxygen (PaO₂) target leads to more days alive without life support — mechanical ventilation, circulatory support or kidney replacement therapy — at day 90.

Included patients either received a minimum of 10 L/minute of oxygen or mechanical ventilation, according to researchers.

Within the total cohort, 697 patients had data on days alive without life support, including 351 patients with a lower oxygenation target and 346 patients with a higher oxygenation target.

A similar number of patients from the lower oxygenation group and the higher oxygenation group did not receive invasive mechanical ventilation at baseline (272 patients vs. 276 patients), but a higher proportion of patients with a higher vs. lower oxygenation target received this type of ventilation during the study period (48.2% vs. 40.4%).

By day 90, researchers found a significantly higher number of days alive without life support among those with a lower vs. higher oxygenation target (median, 80 days vs. 72 days; P = .009), and this remained true after adjusting for baseline risk factors.

Researchers also looked at this outcome by subgroups based on the presence of COPD, hematological malignancy, shock, invasive mechanical ventilation use and PaO₂/FiO2 ratio. The only significant result was observed among those with shock. Similar to the above finding, those with a lower vs. higher oxygenation target had more days alive without life support (median, 75 days vs. 0 days).

Fewer patients with a lower oxygenation target died at 90 days when compared with patients who had a higher oxygenation target (30.2% vs. 34.7%), but this was not significant.

Further, both groups had comparable proportions of patients with a serious adverse event and a similar number of days alive and out of the hospital by the end of the study period.

“Importantly, although COVID-19 therapy and, possibly, virus subgroup virulence changed throughout the pandemic, in the post hoc interaction analysis we found no effect modification of date of inclusion on the primary outcome,” Nielsen and colleagues wrote.