Longitudinal Recovery Trajectories After an Acute Respiratory Distress Syndrome, a New Understanding

The coronavirus disease 2019 (COVID-19) resulted in the largest cohort of critical illness survivors in history, heightened awareness of the importance of the multi-dimensional sequelae after an acute distress respiratory syndrome (ADRS). With the advancement of acute-phase ARDS management, it is unknown whether there are differences in longitudinal recovery trajectories in terms of lung function, symptoms, quality of life, neurocognitive disorders, exercise capacity, chest imaging, and even at molecular basis between patients with post-ARDS due to COVID-19 and due to other causes. This project will continue to generate information about non-COVID-19 post-ARDS based on the experience in our post-COVID consultation that began in May 2020.

The main objective of the study is to identify risk factors of pulmonary sequela in terms of DLCO at long-term follow-up in survivors of ARDS. The investigators are also interested in describing the long-term longitudinal recovery trajectories at a multidimensional level (symptoms, quality of life, neurocognitive, other lung function parameters, exercise capacity, chest imaging and molecular profiles) of ARDS survivors. Furthermore, risk factors as well as recovery trajectories will be compared between ARDS caused by COVID-19 and non-COVID-19. The ultimate goal is to understand the pathobiological mechanisms associated with a severe lung injury at the long term (one year after hospital discharge), in order to provide novel therapeutic targets to develop future intervention studies.

For doing so, adult ARDS survivors of any origin (different than COVID-19) (n=246) referred to the post-CRITICAL consultation at the University Hospitals of Arnau de Vilanova and Santa Maria (Lleida), University Hospital Joan XXIII (Tarragona) and Verge de la Cinta (Tortosa) will be included in this multicentric, prospective, longitudinal and observational study. Previous standardized protocol will be followed at 3, 6 and 12 months after hospital discharge with a complete evaluation of symptoms, neurocognitive, memory problems and quality of life. Lung function, exercise test, chest CT and molecular analysis will be performed at each time point. The prognostic factors and the longitudinal recovery trajectories of ARDS survivors will be assessed using latent class mixed and machine learning artificial models.

The specific objectives to achieve the general objective are the following:

• Objective 1: To identify risk factors of lung function sequelae (spirometry, total lung volumes and lung diffusing capacity) in non-COVID-19 ARDS survivors.
• Objective 2: To identify risk factors of structural pulmonary sequelae (chest CT findings) in non-COVID-19 ARDS survivors.
• Objective 3: To identify risk factors of symptoms, neurocognitive disorders (BC-CCI, MOCA) and quality of life (SF-12) in non-COVID-19 ARDS survivors.
• Objective 4: To develop a clinical scoring tool to predict pulmonary sequelae at short- and long-term follow-up.
• Objective 5: To compare risk factors and recovery trajectories with COVID-19 ARDS survivors using data previously collected.
• Objective 6: To use artificial intelligence to identify multidimensional phenotypes associated with recovery trajectories.
• Objective 7: To design a cost-effective follow-up plan after hospital discharge in ARDS patients based on hospital risk factors.
• Objective 8: To identify molecular profiles according to recovery trajectories in non-COVID-19 ARDS.

Inclusion criteria

• Male and female patients aged ≥18 years
• Admission to the ICU
• Diagnosis of severe pneumonia and/or diagnosis of acute respiratory distress syndrome (ARDS) based on the 2023 definition due to any origin (infectious and non-infectious)

Exclusion criteria

• Life expectancy less than a year
• Transfer to another hospital during hospitalization or follow-up
• Stay in palliative care
• Severe mental disability that makes it impossible to carry out pulmonary function tests during follow-up