Soon after the use of first prone positioning (PP) or proning session in critically ill COVID-19 patients, a marked improvement in oxygen levels was observed, declared a study in Annals of Intensive Care. This further leads to a decreased duration of mechanical ventilation and mortality in these patients.

Proning has been used to improve oxygenation in COVID-19 infected patients. In this cohort study, Gaetano Scaramuzzo and researchers examined if the oxygenation variation following the initial session of proning could be linked to intensive care unit (ICU) ventilator free days (VFD), mortality, and chances of liberation from mechanical ventilation as compared to the before proning stage.

The data from 191 COVID-19 infected patients with ARDS undergoing proning were evaluated. PaO₂/FiO₂ (Arterial oxygen partial pressure (mmHg)/fractional inspired oxygen) percentage change between pre-proning and 1-3 hours following resupination in the first proning session was used to categorize the patients as:

• Responders (more than equal to median PaO₂/FiO₂ variation)
• Non-responders (less than median PaO2/FiO₂ variation)

Assessment of complication rates, physiological variables, and outcomes was done. Following the initial proning session, the median PaO₂/FiO₂ variation was 49 [19–100%] and no differences were witnessed in comorbidities,  ventilatory therapy, demographics, and PaO₂/FiO₂ prior to the use of proning PP between the two groups.

In spite of no differences in ICU duration of stay, the non-responders had a higher rate of tracheostomy and mortality than responders:

At 28 days, the oxygenation response following the first proning was independently linked to ventilator liberation. Thus, sustained oxygenation improvement after the initial PP session is independently linked with improved survival and minimized duration of mechanical ventilation in critically ill patients infected with the coronavirus.