VENTILATION. Strategies to reduce complications and mortality during mechanical ventilation in COVID-19 in ICHC complex ICUs

The infection caused by SARS-CoV2 (COVID-19) has spread around the world and is now considered a pandemic. The most common manifestation of COVID-19 is viral pneumonia with varying degrees of respiratory impairment. Up to 40% of hospitalized patients can develop Acute Respiratory Distress Syndrome (ARDS), with an estimated mortality of 50-60%. The use of high levels of positive end-expiratory pressure (PEEP) has shown controversial clinical outcomes in patients with acute respiratory distress syndrome. One possible reason for these findings is that higher PEEP would be beneficial for patients with greater potential for recruitability, ie, patients in whom the application of higher pressures would result in reduced pulmonary collapse. Currently, PEEP is chosen in most parts of the world using the PEEP vs inspired fraction of oxygen (FIO2) table, ignoring that in some patients a higher PEEP may not help or even worsen oxygenation. This study proposes the use of electrical impedance tomography (EIT) - a non-invasive, radiation-free monitoring method that can be used at the bedside - to assess lung recruitability and select PEEP. The choice of PEEP based on TIE seeks the best compromise between the collapse that occurs at low PEEPs and the hyperdistension that occurs at high PEEPs. OBJECTIVES: The primary objective is to assess the impact of individualized PEEP selection on the severity of ARDS. METHODS: This is a prospective, randomized, open, controlled in 100 patients with early onset (less than 24 hours before randomization) of moderate or severe ARDS due to COVID-19. Eligible patients will be randomly allocated to ventilation guided by TIE (intervention group) or ventilation guided by the PEEP-FIO2 table according to the ARDSNet strategy (control group). All other conduct will be in accordance with institutional protocols. The primary outcome will be the daily modified lung injury scale (Murray score). This scale takes into account chest radiography, compliance, oxygenation and PEEP. It ranges from 0 to 4, with 4 being the maximum score in all domains. The modification automatically assigns a score of 4 to patients who die. Secondary outcomes will be days free from mechanical ventilation, hemodynamic instability, shock, barotrauma. All patients will be monitored with TIE and will undergo a potential recruitability test, with increasing expiratory pressures from 5 to 30 cmH2O, followed by decremental PEEP titration. Then, patients will be randomized in a 1:1 ratio to one of two groups. The randomization list will be generated in blocks of unknown size in order to preserve allocation concealment. Randomization will be performed by an online center, available 24 hours a day. The winning group will be released only after all information about the patient's registration has been registered in the online system.