ultraprotective ventilation without extracorporeal circulation during covid 19 pneumonia

Conditions: Acute Respiratory Distress Syndrome; COVID19; Sars-CoV2; Pneumonia

Summary: 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.


Eligibility criteria:
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)

Keywords: covid19 ards mechanical ventilation ultraprotective ventilation