Résumé
Ultra-protective ventilation is the combination of low airway pressures and tidal volume (Vt) combined with extra corporeal carbon dioxide removal (ECCO2R). A recent large study showed no benefit of ultra-protective ventilation compared to standard ventilation in ARDS patients. However, the reduction in Vt failed to achieve the objective of less than or equal to 3 ml/kg predicted body weight (PBW). The main objective of our study was to assess the feasibility of the ultra-low volume ventilation (Vt ≤ 3 ml/kg PBW) facilitated by ECCO2R in acute respiratory failure patients. Methods: retrospective analysis of a prospective cohort of patients with either high or low blood flow veno-venous ECCO2R devices. Primary endpoint was the proportion of sessions during which a Vt less or equal to 3 ml/kg PBW at 24 hours after the start of ECCO2R was successfully achieved for at least 12 hours. Secondary endpoints were blood flow rates at 24 hours, respiratory variables, rate of adverse events and outcomes. Results: forty-five ECCO2R sessions were recorded among 41 patients. ECCO2R was implemented with 4 different devices. Ultra-low volume ventilation (tidal volume ≤ 3 ml/kg PBW, success group) was successfully achieved at 24 hours in 40.0% sessions (18 out of 45 sessions, confidence interval 25.3–54.6%). High blood flow ECCO2R devices were used in 17 out of 18 sessions (94.4%) in the success group compared to 3 out of 27 sessions (11.1%) in the failure group (p<0,001). At 24 hours, tidal volume in the failure group was 4.1 [3.8-4.5] ml/kg PBW compared to 2.1 [1.9-2.5] in the success group (p<0,001). After multivariate analysis, blood flow rate was significantly associated with success of ultra-low volume ventilation (adjusted OR per 100 ml/min increase 1.51 (95%CI 1.21-1.90, p=0.0003). Conclusion: ultra-low volume ventilation was feasible with tidal volumes down to 2.1 [1.9-2.5] ml/kg PBW in 18 out of 45 sessions. Higher blood flow rates were associated with the success of ultra-low volume ventilation.