Letter (493) In ARDS patients under ECMO, mechanical ventilation (MV) can result rapidly in diaphragmatic weakness and injury and increase MV duration. We observed a delayed reduction of respiratory-system compliance (CRS) in patients under ECMO and controlled MV [1]. APRV is a pressure-controlled mode that has been proposed in ARDS patients to promote SB and to improve lung aeration [3]. This study evaluated the feasibility and safety of a protocol based on APRV, to resume precociously moderate SB under ECMO. We reported eight cases of ARDS under ECMO (Table 1 OSM). We used APRV (V500, PC-APRV mode, Dräger, Lübeck, Germany) to allow additional unassisted SB in complement of strict pressure control MV [1]. APRV was set as follows: airway Pressure ≤28 cmH2O, respiratory frequency 12/min, PEEP ≥10 cmH2O and 1 s inspiratory time. SB was favored by adapting sedation (nurse protocol in OSM) and gas flow to pH, while keeping SB minute ventilation between 30 and 50% of total-minute ventilation (See Figure 1 OSM) [2]. After ECMO removal, pressure support ventilation (PSV) and daily spontaneous breathing trials were used for weaning. Results are expressed as median [range]. Patients spent 78% [44–85] of their time with SB under ECMO, (Table 1 OSM). This time was highly variable and inversely correlated with PSV duration after ECMO removal, R2 0.61, p = 0.02 (Figure 2, OSM). At SB initiation SAS was 1 [1–2], (Table 3, OSM), Driving pressure (DP) of mandatory cycle was 14 [7–16] cmH2O while CRS was 15 [9–29] ml cmH20−1 (Table 1). As results, Mandatory and SB VT were 3.2 [1.7–6.6] vs 1.5 [1.1–6] ml kg−1 PBW, respectively (p = 0.008). The % of SB was 39 [31–50] %. Duration of PSV initiated immediately after ECMO removal was 3 [1–8] days. ...Read less <