This is a prospective, randomized, single-center, open-label controlled trial, designed to compare the efficacy of two ventilation strategies (Low Tidal Volume and positive end-expiratory pressure (PEEP) based on the Acute Respiratory Distress Syndrome (ARDS) Network low PEEP-fraction of inspired oxygen inspired oxygen fraction (FIO2) Table versus Low Driving Pressure and PEEP guided by Electrical Impedance Tomography (EIT) in reducing daily lung injury score in patients with acute respiratory distress syndrome caused by COVID-19. The two strategies incorporate different prioritizations of clinical variables. The PEEP-FIO2 table strategy aims to reduce lung overdistension, even if it requires tolerating worse gas exchange. EIT-guided strategy prioritizes mechanical stress protection, avoiding alveolar overdistension and collapse.
Mechanical ventilatory strategy of the ARDS Network low PEEP-FiO2 table will be followed in
the control arm. This strategy consists of at least 12 hours of controlled mechanical
ventilation following prespecified PEEP and FiO2 combinations chosen dynamically targeting
oxygenation. Tidal volume is set at 4-6 mL/Kg of predicted body weight (PBW) and plateau
pressure is kept below 30 centimeters of water (cmH2O). Respiratory rate can be as high as 35
breaths per minute titrated to a potential of hydrogen (pH) 7.30-7.45. As oxygenation
improves, patients are transitioned to assisted ventilation and then to pressure support
ventilation until they are ready to be liberated from the ventilator. During this phase, no
attempt is made to control plateau pressures or tidal volumes. In the intervention arm,
minimizing tidal lung strain by keeping driving pressure below 16 cmH2O throughout the
mechanical ventilation period will be targeted. The controlled phase will last at least 48
hours. PEEP will be selected according to a PEEP titration maneuver with EIT at the start of
the intervention. This PEEP level will be kept until extubation. Respiratory rate can be as
high as 50 breaths per minute targeting a pH of 7.15-7.45.
Other: EIT-Group
A mechanical ventilation strategy with the main goal to maintain DP < 16 cmH2O
Other: ARDSNet
Low PEEP-FiO2 table ARDS Network ventilation protocol
Inclusion Criteria:
Patients under mechanical ventilation with ARDS (Berlin definition) caused by SARS-COV2
infection:
- ARDS diagnosis in less than 24 hours
- Respiratory System Compliance of 0.6 mL/cmH2O/Kg of PBW
Exclusion Criteria:
- Age < 18 years
- Active bronchopleural fistula
- History of chronic and disabling respirator disease, requiring home oxygen treatment
- Chronic pulmonary arterial hypertension (pulmonary artery systolic pressure > 40 mmHg)
- Huge intrathoracic tumoral mass
- Electrical impedance tomography monitoring contraindications (as thoracic wounds or
burns, electronic implantable devices)
- Hemodynamic instability (systolic pressure < 80 mmHg or mean arterial pressure < 60
mmHg, despite vasopressor drugs; and/or heart rate < 55bpm) - this patient may be
included after recovered from hemodynamic instability
- Not drained pneumothorax or subcutaneous emphysema or bronchopleural fistula
- Patients at risk of intracranial hypertension development or post Cardiopulmonary
resuscitation (first 72 hours)
- Pregnancy
- Impossibility of monitoring with EIT
- Not committed to full support or life expectation < 24 hours
- Legal responsible or clinical team refusal to participate in the study.
USP Instituto do Coração
São Paulo, Brazil
Investigator: Eduardo LV Costa
Contact: +551130667361
eduardoleitecosta@gmail.com
Eduardo LV Costa, PhD
+551130617361
eduardoleitecosta@gmail.com
Maria AM Nakamura, PhD
+551130617151
mamiyukinakamura@gmail.com
Eduardo LV Costa, PhD, Principal Investigator
Hospital das Clinicas from University of São Paulo