Mechanical ventilation in COVID-19

COVID-19 can progress to a critical condition with acute respiratory distress syndrome, characterized by alveolar collapse, exudative infiltrate with an intense inflammatory response, which can progress to biotrauma and multiple organ failure. In cases of severe respiratory failure refractory to oxygen therapy or non-invasive support, invasive mechanical ventilation is indicated based on clinical and blood gas analysis criteria. This constitutes a life-support therapy aimed at maintaining gas exchange while pulmonary recovery occurs. During the pandemic, different COVID-19 phenotypes with respiratory compromise were described, ranging from relatively preserved compliance and predominantly impaired perfusion (phenotype L) to presentations like classic acute respiratory distress syndrome with high elastance, pulmonary edema, and greater recruitment potential (phenotype H). These phenotypes can evolve dynamically, which explains the clinical heterogeneity and the variable response to interventions such as prone positioning. Initial ventilation programming should be individualized, usually using volume-controlled modes, and continuous monitoring, including static and dynamic variables; this is essential for ventilatory optimization and reducing ventilator-induced lung injury. Furthermore, alveolar recruitment and prone positioning are key strategies in moderate to severe respiratory distress syndrome, with evidence of reduced mortality when implemented early and for an extended period.