Figure 1. 90-day survival according to the time between mechanical ventilation and ECMO implantation. ECMO: extracorporeal membrane oxygenation; MV: mechanical ventilation.

Figure 2. 90-day survival according to the time between non-invasive ventilation + mechanical ventilation and ECMO implantation. ECMO: extracorporeal membrane oxygenation; NIV: non-invasive ventilation; MV: mechanical ventilation.

Figure 3. 90-day survival according ECMO patients managed or not managed by an experienced and dedicated team. ECMO: extracorporeal membrane oxygenation.

Table 1. Overall demographic, clinical, biological, hemodynamic, and mechanical ventilation characteristics before and on ECMO according to 90-day survival status and depending on the wave vs. other waves).

Table 1. Overall demographic, clinical, biological, hemodynamic, and mechanical ventilation characteristics before and on ECMO according to 90-day survival status and depending on the wave vs. other waves).

Clinical CharacteristicsAll (n = 41)Survivors (24)Non-Survivors (17)pFirst Wave (17)Other Waves (24)pAt ICU admission  Gender (female/male)14/2710/144/130.017/107/17NS Age (years)57 (52–63)57 (47–61)58 (53–66)NS57 (54–64)57 (47–61)NS-BMI (kg/m2)28 (26–32)28.5 (26–31.75)28 (25–34.5)NS26.2 (24.9–29.4)29.4 (26.6–32.5)NS-SAPS II57 (47–67)56 (38–63)59 (52–67)NS59 (53–68)56 (38–63)0.0317Comorbidities  Hypertension n (%)13 (34)9 (38)4 (24)NS6 (35)7 (29)NS Diabetes n (%)14 (37)8 (33)6 (35)NS5 (29)9 (38)NS Obesity n (%)15 (37)10 (42)5 (29)NS3 (18)12 (50)0.0182 Immunosuppression n (%)4 (11)2 (8)2 (12)NS4 (24)0 (0)0.0124 Asthma/COPD n (%)2 (5)1 (4)1 (6)NS2 (12)0 (0)NS None n (%)10 (26)5 (21)5 (29)NS2 (12)8 (33)NS Time from symptoms to hospital admission (days)5 (3–7)5 (3–7)6 (3.5–7.5)NS4 (3–7)6 (5–9)0.0279 Time from hospital to IMC (Days)0 (0–1)0 (0–1)0 (0–1)NS0 (0–0.5)0 (0–1)NS Time from IMC to ICU (Days)2 (0–4.5)2 (0–3)3 (1–7)NS1 (0–5)3 (1–5)NSLaboratory  Hb (g/L)126 (98–139)129 (109–139)102 (94–132)NS96 (87–105)131 (125–146)<0.0001 WCC (G/L)9.5 (6.1–11.7)8.5 (5.5–10)10.6 (9.2–12.9)NS9.6 (5.3–12.7)9.4 (6.9–10.5)NS Lymphocytes (G/L)0.59 (0.28–0.81)0.5 (0.3–0.7)0.7 (0.6–0.9)NS0.56 (0.2–0.85)0.62 (0.28–0.75)NS N/L ratio17 (9–25)19 (9–28)17 (10–21)NS17 (9–41)17 (10–23)NS Thrombocytes (G/L)275 (192–347)265 (188–324)276 (234–374)NS275 (183–354)278 (194–348)NS Ddimers (ng/mL)2421 (972–8090)1039 (726–1924)4302 (1925–9681)0.013411 (1775–8769)1039 (723–4625)NS CRP (mg/L)95 (38–208)93 (42–173)168 (25–250)NS171 (65–306)64 (23–130)0.003 Procalcitonin (µg/L)0.22 (0.15–0.72)0.2 (0.14–0.78)0.25 (0.17–0.63)NS0.29 (0.21–1.08)0.18 (0.08–0.44)0.0055 Us-troponin (ng/L)23 (7–49)23 (6–42)25 (15–107)NS28 (17–57)13 (5.8–41)NS Creatinine (µmol/L)63 (55–76)64 (57–77)61 (54–77)NS62 (54–79)63 (57–74)NS Urea (mmol/L)7.9 (5.6–9.2)7.1 (5.2–8.3)8 (7.2–10.5)NS8.1 (6.5–10.5)7.4 (5.2–8.1)NS Lactate (mmol/L)1.4 (1.2–2)2 (0–3)3 (1–7)NS1.5 (1.2–2.1)1.4 (1.1–1.8)NSAt ECMO implantation  HR (BPM)89 (79–100)87 (78–99)94 (79–101)NS81 (78–99)91 (80–102)NS MAP (mmHg)75 (72–77)75 (72–77)74 (68–78)NS75 (70–18)75 (72–77)NS Norepinephrine (µg/kg/min)0.08 (0.04–0.12)0.08 (0.03–0.12)0.09 (0.03–0.12)NS0.08 (0.01–0.11)0.1 (0.04–0.12)NS Temperature (°C)36.9 (36.6–37.1)36.9 (36.6–37)36.9 (36.5–37.5)NS37 (36.6–27.8)36.8 (36.5–37)NS Lung lesions on CT-Scan (%)70 (60–75)75 (53–75)75 (75–75)NS75 (68–75)75 (53–75)NS Ventilatory mode, nb (%)ACV 41 (100)ACV 24 (100)ACV 17 (100)NSACV 17 (100)ACV 24 (100)NS P/F ratio before ECMO (kPa)9.5 (7.7–11.1)10 (8–12)8.3 (7.2–10.1)NS10 (8–11.5)9 (7.3–11.1)NS Vt (mL)380 (343–465)405 (346–478)370 (335–423)NS370 (340–388)450 (352–480)0.0132 Vt/PBW (mL/kg)6.2 (5.7–6.7)6.4 (5.7–7.1)6.2 (4.9–6.6)NS5.8 (4.7–6.5)6.4 (6.2–7.1)0.031 Plateau pressure (cmH2O)29 (27–31)28 (24–30)30 (28–32)0.0129 (28–31)28 (24–31)0.045 PEEP (cmH2O)12 (10–12)11 (10–12)12 (10–13)NS12 (10–12)11 (10–13.5)NS Respiratory rate (Breath/min)23 (20–28)23 (20–27)24 (20–28)NS25 (20–29)22 (20–26)NS Compliance (mL/cmH2O)24 (20–27)25 (21–32)22 (17–25)0.0321 (17–24)25 (22–33)0.001 Prone positioning/patient1 (1-2.5)1 (0-1)3 (1-4)0.00458 (47)13 (54)NS iNO (nb)23 (56)11 (46)12 (72)NS12 (71)11 (46)NS Neuromuscular blockers (nb)40 (98)23 (96)17 (100)NS17 (100)23 (96)NS Mechanical ventilation ≤3 days, nb (%)19 (46.3)15 (62.5)4 (23.5)0.0252 (11.8)17 (70.8)<0.0001 Mechanical ventilation >3 days, nb (%)22 (53.6)9 (37.5)13 (76.5)0.02515 (88.2)7 (29.2)<0.0001 Total ventilation time before ECMO (days)7 (4–11)5.5 (1.3–9)9 (6.5–13.5)0.00269 (6–13.5)6 (2–9)0.0249 Duration of mechanical ventilation before ECMO (days)4 (1–7)1.6 (0.4–5.5)5.8 (5–8)<0.00017 (5–8.5)1.5 (0–4.8)<0.0001On ECMO  Ventilatory mode, nb (%)ACV 41 (100)ACV 24 (100)ACV 17 (100)NSACV 17 (100)ACV 24 (100)NS Vt (mL)320 (210–345)320 (225–355)300 (210–340)NS320 (265–360)320 (200–345)NS Vt/PBW (mL/kg)4.3 (3.8–5.6)4.7 (3.9–5.7)4.3 (3.6–4.8)NS4.7 (4.2–5.7)4.3 (3.5–5.3)NS Plateau pressure (cmH2O)24 (22–26)24 (20.3–25.8)24 (22.5–26.5)NS25 (23.5–29.5)24 (20–24)0.0126 PEEP (cmH2O)10 (10–12)10 (10–12)10 (10–13)NS10 (10–11.5)10 (8.5–12)NS Respiratory rate (Breath/min)11 (10–19)11 (10–17)10 (10–20)NS18 (11–24)10 (10–12)0.002 Compliance (mL/cmH2O)23 (17–30)23 (18–31)22 (15–29)NS22 (15–29)25 (18–31)NS Prone positioning, nb (%)21 (51)1 (0–1)3 (1–4)0.00218 (47)13 (54)NS ECMO team in charge, nb (%)23 (66)18 (75)5 (21)0.00125 (29)19 (79)0.0009 Mobile ECMO, nb (%)12 (29)7 (29)5 (29)NS5 (29)7 (29)NS Reinjection cannula (French)19 (19–21)20 (19–21)19 (19–21)NS19 (19–19)21 (19–21)0.0068 Drainage cannula (French)28 (25–29)27.5 (25–29)26.5 (25–29)NS25 (25–28)29 (25–29)0.0041 AVALON cannula, nb (%)9 (22)6 (25)3 (18)NS1 (6)8 (33)0.0364 VA-ECMO, nb (%)2 (5)2 (5)0 (0)NS0 (0)2 (5)NS VV-ECMO, nb (%)39 (95)22 (95)17 (100)NS17 (100)22 (95)NS ECMO blood flow (L/min)5.0 (4.5–5.9)5 (4.1–5.6)5.5 (4.8–6)NS5 (4.8–5.6)5.1 (4–6)NS Sweep gas flow (mL/min)8 (7–10)8 (7–10)9 (8–14)0.0418 (7.5–10)8 (7–10)NS ScvO2 at ECMO full flow (%)69 (64–75)67.5 (62–72)73 (66–76.5)NS73 (69–76)66 (61–72)0.0358 AntiXa (UI/mL)0.31 (0.29–0.33)0.32 (0.29–0.33)0.31 (0.29–0.32)NS0.30 (0.29–.033)0.31 (0.29–0.32)NS Time on ECMO (Days)20 (10–37)14 (9–37)30 (20–37)NS24 (10–33)17 (10–56)NS Membrane changes/patient, nb (%)2 (1–4)1 (0–3)2 (1–4)NS2 (1–3)1 (0–4)NS Tracheotomy, nb (%)22 (54)11 (46)11 (65)NS12 (71)11 (46)NS CVVHDF3 (8)2 (8)1 (6)NS0 (0)3 (13)NSCOVID-19 adjunctive treatment  Hydroxychloroquine, nb (%)10 (26)5 (21)5 (29)NS10 (59)0 (0)<0.0001 Lopinavir + Ritonavir, nb (%)9 (22)4 (17)5 (29)NS9 (53)0 (0)<0.0001 Remdesivir, nb (%)8 (20)5 (21)3 (18)NS3 (18)5 (21)NS Dexamethasone, nb (%)28 (68)17 (71)11 (65)NS5 (29)23 (96)<0.0001 Tociluzimab, nb (%)22 (54)15 (63)7 (41)NS2 (12)20 (83)<0.0001 Meduri, nb (%)27 (66)13 (54)14 (82)NS14 (82)13 (54)NSCOVID-19 related complications  Pneumothorax, nb (%)14 (34)5 (21)9 (53)0.03273 (18)11 (48)NS Pneumomediastinium, nb (%)8 (20)6 (25)2 (12)NS1 (6)7 (30)NS Pulmonary embolism, nb (%)10 (26)6 (25)4 (24)NS0 (0)10 (43)0.0022 Ventilator-associated pneumonia, nb (%)38 (93)22 (92)16 (94)NS14 (82)24 (100)0.0325 Aspergillosis, nb (%)14 (34)9 (38)5 (29)NS3 (18)11 (48)NSICU length of stay (days)36 (21–45)29 (17–45)37 (31–44)NS33 (21–41)37 (21–67)NSHospital length of stay (days)45 (33–69)45 (30–70)42 (33–60)NS42 (32–56)45 (38–74)NSMajor adverse event, nb (%)2 (5)0 (0)2 (12)NS2 (12)0 (0)NS90-day survival, nb (%)24 (59)24 (100)0 (0)<0.00016 (35)17 (74)0.024

Table 2. Association between days under mechanical ventilation and total days of ventilation before ECMO and 90-day mortality.

Table 2. Association between days under mechanical ventilation and total days of ventilation before ECMO and 90-day mortality.

90-Day Mortality in Patients under ECMO OR (95% CI)pTime under MV before ECMO ≤3 daysRef. 0.03>3 days4.9 (1.1–20.9) Time under NIV and MV before ECMO ≤7 daysRef. >7 days4 (1.1–15.7)0.049SAPSII1.03 (0.9–1.1)0.3Plateau pressure <28 cmH2ORef. ≥28 cmH2O1.1 (0.2–6)0.9

Table 3. Association between having an ECMO team in charge of the patient and 90-day mortality.

Table 3. Association between having an ECMO team in charge of the patient and 90-day mortality.

90-Day Mortality OR (95% CI)pECMO team in charge0.2 (0.001–0.2)<0.01SAPSII1 (0.9–1.1)0.9Duration of MV before implantation of ECMO > 72 h 1.3 (0.2–9.2)0.8