Ultraprotective Ventilation Without Extracorporeal Circulation During COVID 19 Pneumonia

Open Label Randomized Controlled Trial of Ultraprotective Ventilation Without Extracorporeal Circulation in Patients With COVID 19 Pneumonia and Moderate to Severe ARDS

Mortality of COVID-19 pneumonia with acute respiratory distress syndrome (ARDS) is extremely high in preliminary reports amounting to 50-60%. Duration of mechanical ventilation in these patients appears to exceed standard duration of mechanical ventilation in non-COVID-19 ARDS patients, suggesting that COVID-19 patients may be particularly at risk for ventilator-induced lung injury. Treatment of COVID-19 ARDS patients is to date mainly supportive with protective mechanical ventilation (ventilation with low tidal volume (VT) i.e. 6 ml/kg of predicted body weight (PBW) and plateau pressure control below 30 cm H2O).

Mechanical ventilation with VT reduction below 6 ml/kg PBW in ARDS may reduce alveolar strain, driving pressure and hence ventilator-induced lung injury. Investigators recently performed a multicenter pilot study on 34 moderately severe to severe ARDS patients. This study demonstrated that ultraprotective ventilation with ultra-low VT (≤4.2 ml/kg PBW) without extracorporeal circulation may be applied in approximately 2/3 of the patients, with a 4 cmH2O median reduction in driving pressure, at the price of transient episodes of severe acidosis in approximately 1/3 of the patients. Investigators hypothesized that ultraprotective ventilation without extracorporeal circulation may reduce the mortality at day-90 and increase the number of days free from mechanical ventilation (VFD) at day-60, as compared to protective ventilation.

Inclusion Criteria:

• Adults aged 18 years or older
• ARDS according to the Berlin definition
• COVID-19 pneumonia confirmed by RT-PCR
• Acute respiratory failure not fully explained by left ventricular failure or sodium overload
• Bilateral pulmonary radiological opacities not fully explained by pleural effusions or atelectasis or nodules
• Invasive mechanical ventilation with PaO2/FiO2 ≤ 150 mm Hg and PEEP ≥ 5 cm H2O with a tidal volume below or equal to 6 ml per kilogram of predicted body weight
• Continuous intravenous sedation as part of ARDS treatment

Exclusion Criteria:

• Exclusion criteria related to ARDS history

  • ARDS onset more than 48 hours before inclusion
  • previous inclusion in present study

• Exclusion criteria related to ARDS severity or complications

  • arterial pH < 7.21 despite respiratory rate set to 35/min at the time of inclusion
  • patient under any extracorporeal CO2 removal technique or ECMO
  • pneumothorax or bronchopleural fistula

• Exclusion criteria related to comorbidities

  • suspected intracranial hypertension
  • severe chronic obstructive pulmonary disease defined by a GOLD score ≥ 3
  • chronic respiratory failure under home oxygen or non-invasive ventilation
  • chronic respiratory failure requiring long term oxygen or non-invasive ventilation
  • obesity with body weight over height ratio greater than 1 kg/cm
  • sickle cell disease
  • bone marrow transplant < 6 months
  • burn injury with extension greater than 30% of body surface area
  • cirrhosis with Child-Pugh score C
  • advance directives to withhold or withdraw life sustaining treatment

• Exclusion criteria related to legislation

  • Patient under an exclusion period relative to participation to another clinical trial, or inclusion into a clinical trial interfering with the ventilatory strategies
  • pregnancy, lactating women
  • patient under a legal protective measure.
  • lack of affiliation to social security as required by French regulation
  • lack of written informed consent by patient or next of kin (unless if recourse to the emergency procedure in the absence of a loved one)