Severe COVID-19 Patients Recover Faster from High-Flow Oxygen Therapy

Gustavo A Ospina-Tascon, MD, PhD

A new study evaluated the effect of high-flow oxygen therapy compared with conventional oxygen therapy on invasive mechanical ventilation and clinical recovery in patients with severe COVID-19.

Gustavo A Ospina-Tascon, MD, PhD, Department of Intensive Care, Fundacion Valle del Lili, led a team of investigators that examined how effective high-flow oxygen therapy through a nasal cannula was when compared with conventional oxygen therapy on need for endotracheal intubation and clinical recovery in severe COVID-19 patients.

The use of high-flow oxygen through a nasal cannula had a significant effect on decreasing the need for mechanical ventilation support and time to clinical recovery in patients with severe COVID-19. This method was found to be more effective than conventional low-flow oxygen therapy.

Finding a Better Way

Investigators wanted to help establish the types of oxygen therapy in the setting of severe COVID-19, especially because when the number of severe cases that require hospitalization increases, it puts strain on health care system capacities.

The leading feature that presents in severe COVID-19 cases is arterial hypoxemia. To manage this, oxygen supplementation is utilized in hopes of improving oxygenation and to assist respiratory effort.

Observational studies conducted from the early part of the pandemic showed high mortality in patients subjected to invasive mechanical ventilation. However, patient self-inflicted lung injury can occur in nonintubated patients with acute respiratory failure during spontaneous breathing.

Noninvasive respiratory support techniques have the potential to limit self-inflicted lung injury while preventing adverse events associated with intubation and mechanical ventilation.

“High-flow oxygen therapy through a nasal cannula is a technique whereby a mixture of heated and humidified oxygen and air are delivered to the nose at high flow rates,” investigators wrote.

International guidelines have recommended this therapy based on early observational studies but the evidence to support this is limited. Existing data suggest high-flow oxygen therapy might decrease necessitating endotracheal intubation and risk of escalation of therapy.

However, the data do not indicate an effect on mortality rates.

Promising Outcomes

The analysis included 199 of the 220 randomized patients (median age, 60 years; 32.7% women). Need for intubation and time to clinical recovery were the co-primary outcomes.

For patients randomized to high-flow oxygen therapy, intubation occurred in 34.3% (34) of patients. Those randomized to conventional oxygen therapy had a higher rate of intubation at 51% (51).

As for time to clinical recovery within 28 days, 11 days was the median time for patients receiving high-flow oxygen therapy compared with 14 days for those receiving conventional oxygen therapy.

The presence of suspected bacterial pneumonia occurred in 13.1% (13) of patients in high-flow oxygen therapy and 17% (17) of patients in conventional oxygen therapy. Bacteremia was also detected in patients, 7.1% (7) in the high-flow oxygen group and 11% (11) in the control group.

Evaluating the Oxygen Flow

After random assignment, 109 patients received high-flow oxygen through a nasal cannula and 111 patients received conventional oxygen therapy for treatment of severe COVID-19.

The randomized, open-label clinical trial was conducted in emergency and intensive care units and consisted of 220 adults with respiratory distress and a ratio of partial pressure of arterial oxygen to fraction of inspired oxygen of less than 200 due to COVID-19.

This research took place in 3 hospitals in Colombia from August 2020-January 2021, with the last follow-up taking place in February 2021. A Cox proportional hazards model adjusted for hypoxemia severity, age, and comorbidities, was used to calculate the effects of the treatments.

Clinical recovery was achieved by 77.8% (77) of patients on high-flow oxygen therapy compared with 71% (71) of patients on conventional oxygen therapy.

These findings were significant and supported the motivation that high-flow oxygen therapy decreases the need for mechanical ventilation support and the time to clinical recovery.

The study was titled "Effect of High-Flow Oxygen Therapy vs Conventional Oxygen Therapy on Invasive Mechanical Ventilation and Clinical Recovery in Patients With Severe COVID-19".