Efficacy and safety of lower versus higher CO₂ extraction devices to allow ultraprotective ventilation: secondary analysis of the SUPERNOVA study.

Abstract

Retrospective analysis of the SUPERNOVA trial exploring the hypothesis that efficacy and safety of extracorporeal carbon dioxide removal (ECCO₂R) 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 <i>lower</i> (area of membrane length 0.59 m²; blood flow 300-500 mL/min) and <i>higher</i> (membrane area 1.30 m²; blood flow between 800 and 1000 mL/min) CO₂ extraction capacity. Ninety-five patients with moderate ARDS were included (33 patients treated with <i>lower</i> and 62 patients treated with <i>higher</i> CO₂ 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 ECCO₂R-related haemolysis and bleeding was higher with <i>lower</i> than with <i>higher</i> 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 <i>higher</i> CO₂ extraction capacity.