Efficacy and safety of lower versus higher CO 2 extraction devices to allow ultraprotective ventilation: Secondary analysis of the SUPERNOVA study

Retrospective analysis of the SUPERNOVA trial exploring the hypothesis that efficacy and safety of extracorporeal carbon dioxide removal (ECCO 2 R) to facilitate reduction of tidal volume (V T) to 4 mL/kg in patients with acute respiratory distress syndrome (ARDS) may differ between systems with lower (area of membrane length 0.59 m 2; blood flow 300-500 mL/min) and higher (membrane area 1.30 m 2; blood flow between 800 and 1000 mL/min) CO 2 extraction capacity. Ninety-five patients with moderate ARDS were included (33 patients treated with lower and 62 patients treated with higher CO 2 extraction devices). We found that (1) V T of 4 mL/kg was reached by 55% and 64% of patients with the lower extraction versus 90% and 92% of patients with higher extraction devices at 8 and 24 hours from baseline, respectively (p<0.001), and (2) percentage of patients experiencing episodes of ECCO 2 R-related haemolysis and bleeding was higher with lower than with higher extraction devices (21% vs 6%, p=0.045% and 27% vs 6%, p=0.010, respectively). Although V T of 4 mL/kg could have been obtained with all devices, this was achieved frequently and with a lower rate of adverse events by devices with higher CO 2 extraction capacity.