Outcomes, Sequelae, and Ventilatory Strategies in Long COVID Patients with Severe ARDS: A Retrospective Cohort Study

Background and Aims: Severe acute respiratory distress syndrome (ARDS) in patients with long COVID remains associated with extremely high mortality and significant long-term sequelae. Non-invasive ventilatory strategies such as continuous positive airway pressure (CPAP) and high-flow nasal cannula (HFNC) are widely used before endotracheal intubation (ETI). Still, their comparative effectiveness in this population is not well established. Understanding survival outcomes and sequelae can help refine treatment strategies for this high-risk group. This study aimed to evaluate outcomes, sequelae, and treatment strategies in long COVID patients with severe ARDS, focusing on non-invasive ventilatory support before ETI. Materials and Methods: A retrospective cohort analysis was performed using a study comparing severe ARDS patients with and without COVID-19. The inclusion criterion was a Horovitz quotient (PaO2/FiO2) < 50 mmHg. Results: The study included a total of 59 patients diagnosed with long COVID-19 ARDS, with a mortality rate of 85%. A significant proportion of the patient population was male, accounting for 75%. The highest survival rate was observed among patients who initially received CPAP support, with a survival rate of 23.08%, in contrast to those treated solely with HFNC or those who alternated between HFNC and CPAP. Among patients who required endotracheal intubation and subsequent mechanical ventilation, survival rates were 40% for those who had previously received CPAP, 10% for those treated with alternating HFNC and CPAP, and 0% for those managed exclusively with HFNC before ETI. Survivors often exhibited sequelae, such as impaired pulmonary function, persistent dyspnea, and diminished physical performance. Conclusions: Patients with long COVID who develop severe ARDS (PaO2/FiO2 < 50 mmHg) face exceptionally high ICU mortality, with outcomes determined mainly by age, comorbidities, and profound hypoxemia. Although CPAP showed a trend toward improved survival, the data do not establish superiority and should be regarded as hypothesis-generating. Rather, they highlight the complexity of managing this underrepresented subgroup and underscore the need for larger, multicenter studies with broader inclusion criteria to confirm or refute these preliminary observations.