[Comparison of efficacy between veno-venous extracorporeal membrane oxygenation (VV-ECMO) and VV-ECMO combined with prone position ventilation for the treatment of acute respiratory distress syndrome].

OBJECTIVE: To observe the effects of veno-venous extracorporeal membrane oxygenation (VV-ECMO) combined with prone position ventilation (PPV) on oxygenation index (PaO2 /FiO2 ), respiratory compliance (Crs) and vasoactive inotropic score (VIS) in severe acute respiratory distress syndrome (ARDS) patients.

METHODS: Eighteen patients with severe ARDS requiring VV-ECMO support in Liuzhou People's Hospital from June 2018 to April 2020 were selected for retrospective analysis, and 8 patients among of these cases received PPV after VV-ECMO. The differences in PaO2 /FiO2 , VIS and Crs before and 1, 2 or 3 days after treatment were compared between VV-ECMO group and VV-ECMO combined with PPV group, as well as the differences in these indices before PPV and 2 hours after PPV daily in VV-ECMO combined with PPV group. The incidence of adverse events in two groups were also observed.

RESULTS: Before treatment, there was no significant difference in PaO2 /FiO2 , Crs between two groups. Over time, PaO2 /FiO2 and Crs increased and VIS decreased in both groups. Compared with before treatment, there were statistically significant differences in PaO2 /FiO2 and VIS from 1 day after treatment [PaO2 /FiO2 (mmHg, 1 mmHg = 0.133 kPa): VV-ECMO group was 197.75±39.80 vs. 75.57±7.44, VV-ECMO combined with PPV group was 255.20±31.92 vs. 68.24±11.64; VIS: VV-ECMO group was 5.51±3.72 vs. 10.20±7.10, VV-ECMO combined with PPV group was 6.73±3.32 vs. 14.50±2.48, all P < 0.05], up to 3 days after treatment [PaO2 /FiO2 (mmHg): VV-ECMO group was 231.96±32.76 vs. 75.57±7.44, VV-ECMO combined with PPV group was 285.61±19.40 vs. 68.24±11.64; VIS: VV-ECMO group was 2.26±1.90 vs. 10.20±7.10, VV-ECMO combined with PPV group was 2.13±1.55 vs. 14.50±2.48, all P < 0.05], and the PaO2 /FiO2 1 day and 3 days after treatment in VV-ECMO combined with PPV group were significantly higher than those in VV-ECMO group (mmHg: after 1 day of treatment was 255.20±31.92 vs. 197.75±39.80, after 3 days of treatment was 285.61±19.40 vs. 231.96±32.76, both P < 0.05). Before treatment, Crs of VV-ECMO combined with PPV group was significantly lower than that of VV-ECMO group (mL/cmH2 O: 17.91±0.82 vs. 20.54±1.26, P < 0.05). From 1 day after treatment, the Crs in VV-ECMO combined with PPV group was significantly higher than that before treatment (mL/cmH2 O: 21.20±1.50 vs. 17.91±0.82), the peak value was (24.93±2.18) mL/cmH2 O on 3 days after treatment, however, there was no significant difference between the two groups (all P < 0.05). In VV-ECMO combined with PPV group, compared with before PPV treatment, the PaO2 /FiO2 and Crs of 2 hours after PPV treatment in 1, 2 and 3 days were significantly rose, and it reached the highest level in 3 days [PaO2 /FiO2 (mmHg): 285.61±19.40 vs. 189.91±28.34, Crs (mL/cmH2 O): 24.93±2.18 vs. 23.35±1.45, both P < 0.05]; the VIS was only increased in 2 hours after PPV treatment on the first day than before (6.73±3.32 vs. 6.38±3.22, P < 0.05). There were no related serious adverse events happened after PPV treatment.

CONCLUSIONS: The combination of PPV during VV-ECMO could further increase PaO2 /FiO2 , improve hypoxemia and implement further protective lung ventilation to reduce the potential hazards during mechanical ventilation. In addition, no serious adverse events were observed in this study, suggesting PPV is safe during VV-ECMO.