Prognostic Value of the Veno-Arterial Carbon Dioxide Difference in COVID-19-Associated Acute Hypoxemic Respiratory Failure: A Retrospective Cohort Study

Background/Objectives: In acute hypoxemic respiratory failure, hyperventilation and alterations in oxygenation can influence CO2 kinetics via the Haldane effect, potentially modifying the venous-to-arterial carbon dioxide partial pressure gradient (PvaCO2) irrespective of tissue perfusion, thereby complicating its prognostic significance. This study assessed the predictive importance of PvaCO2 in critically ill patients experiencing acute respiratory failure linked to COVID-19.