Table 2.
Comparison of patient’s characteristics according to their survival at day 90 in univariate analysis
| All (n = 76) | Survivors at D90 (n = 39) | Non-survivors at D90 (n = 37) | p value | |
|---|---|---|---|---|
| Demographic characteristics | ||||
| Age (years) | 61 (54–64.5) | 58 (49–62) | 63 (59–66) | < 0.001 |
| Male sex, n (%) | 59 (77.6) | 30 (77) | 29 (78) | 0.88 |
| BMI (kg/m2) | 28.1 (26.1–31.8) | 30.5 (27.2–35) | 27.2 (25.6–29.9) | 0.002 |
| Obesitya | 29 (39.7%) | 21 (53.8%) | 8 (23.5%) | 0.008 |
| ECMO Referral Center, n (%) | 42 (55) | 23 (59) | 19 (51) | 0.50 |
| Transfer from referring hospital by ECMO mobile team | 33 (43) | 19 (49) | 14 (38) | 0.34 |
| Characteristics of Sars-CoV 2 pneumonia and treatments | ||||
| First wave, n (%) | 23 (30) | 18 (46) | 5 (13.5) | 0.002 |
| Time from first symptoms to ICU admission, (days) | 7 (5.5–10) | 5 (4–7) | 6 (4–7) | 0.43 |
| Time from ICU admission to intubation, (days) | 3 (0–6) | 2 (0–5) | 4 (1–7) | 0.02 |
| Sars-CoV 2 treatment | ||||
| Dexamethasoneb n (%) | 54 (67) | 21 (54) | 33 (92) | < 0.001 |
| Hydroxychloroquine, n (%) | 24 (32) | 17 (44) | 7 (19) | 0.02 |
| Antiviral treatment, n (%) | ||||
| Lopinavir/ritonavir | 3 (4) | 3 (8) | 0 (0) | 0.08 |
| Immunomodulatory treatment, n (%) | ||||
| Anti-IL 6 treatment | 6 (8) | 4 (10) | 2 (5) | 0.43 |
| Anti- IL 1 treatment | 12 (16) | 8 (20.5) | 4 (11) | 0.25 |
| Janus kinase 1/2 inhibitor | 14 (18) | 8 (20.5) | 6 (16) | 0.63 |
| High-dose corticosteroid | 47 (62) | 22 (56) | 25 (68) | 0.32 |
| ICU admission scores | ||||
| Charlson score | 2 (1.5–3) | 2 (1–3) | 3 (2–3) | 0.003 |
| SAPS II | 30 (27–36) | 29 (23–36) | 31 (27–38.5) | 0.42 |
| SOFA | 3 (2–4) | 3 (2–4) | 3 (2–5) | 0.76 |
| ICU therapy before ECMO | ||||
| High-flow nasal O2, n (%) | 67 (88) | 32 (82) | 35 (95) | 0.09 |
| Duration (days) | 3 (1–6) | 2.5 (1–6) | 4 (1–7) | 0.14 |
| Non-invasive ventilation, n (%) | 37 (49) | 17 (44) | 20 (54) | 0.36 |
| Duration (days) | 1 (0–6) | 1 (0–6) | 1 (0–6) | 0.70 |
| Almitrine, n (%) | 12 (16) | 6 (16) | 6 (17) | 0.92 |
| Inhaled nitric oxide, n (%) | 53 (70) | 28 (72) | 25 (68) | 0.69 |
| Prone positioning, n (%) | 75 (99) | 38 (97) | 37 (100) | 0.33 |
| Number of sessions | 2 (1–4) | 2 (1–4) | 2 (1–4) | 0.85 |
| MV duration before ECMO | 6 (3–10) | 5 (3–9) | 7 (3–11) | 0.43 |
| Ventilation parameters before ECMO | ||||
| FiO2 | 100 (100–100) | 100 | 100 | 0.58 |
| Plateau pressure, (cmH2O) | 28 (25–30) | 28 (24–31) | 28 (26–30) | 0.71 |
| Positive end-expiratory pressure, (cmH2O) | 12 (9.5–14) | 12 (10–14) | 12 (9–14) | 0.38 |
| Tidal volume, (mL/kg predicted bodyweight) | 5.8 (5.1–6.2) | 5.7 (5–6.1) | 6.04 (5.3–6.3) | 0.15 |
| Respiratory rate, (breath per minute) | 27 (23–30) | 26 (23–30) | 28 (21–30) | 0.92 |
| Mechanical power, (L/min) | 19.7 (15.7–24) | 19.4 (15.8–22.4) | 19.99 (14.07–24.34) | 0.74 |
| Ventilatory ratio | 2.42 (1.71–2.84) | 2.32 (1.79–2.84) | 2.42 (1.55–2.88) | 0.90 |
| Static compliance, (mL/cmH2O) | 23 (16.7–28.6) | 23.3 (15.2–30.8) | 22.7 (20–27.3) | 0.63 |
| Last blood-gas values before ECMO | ||||
| PaO2/FiO2 ratio | 71.5 (62–81) | 72.5 (60–83) | 71.5 (65.5–80) | 0.97 |
| pH | 7.33 (7.25–7.38) | 7.31 (7.25–7.39) | 7.35 (7.25–7.37) | 0.73 |
| PaCO2, (mmHg) | 58 (51–66) | 58 (52–66) | 58 (49–66) | 0.85 |
| Predictive survival scores under ECMO | ||||
| RESP score | 1 (0–2) | 1 (1–4) | 1 (0–2) | 0.01 |
| ECMO net score | 5 (4–6) | 4.5 (4–6) | 5 (4–6.25) | 0.79 |
| PRESERVE score | 3 (2–4) | 2 (1–4) | 3 (3–5) | < 0.001 |
| Last SOFA before ECMO | 7 (4–9) | 7 (4–10) | 7 (4.5–9) | 0.94 |
| Respiratory component of SOFA | 4 (4–4) | 4 (4–4) | 4 (4–4) | 0.33 |
| Cardiovascular component of SOFA | 2 (0–4) | 3 (0–4) | 1 (0–4) | 0.62 |
| Hematological component of SOFA | 0 (0–0 | 0 (0–0) | 0 (0–0) | 0.55 |
| Renal component of SOFA | 0 (0–1) | 0 (0–0) | 0 (0–0) | 0.09 |
| Time from ICU admission to ECMO, (days) | 10.5 (7–13) | 9 (4–11) | 11 (8–14) | 0.02 |
| ECMO assistance duration, (days) | 18 (11–31.5) | 14 (9–23) | 27 (15–39) | < 0.001 |
| Prone positioning during ECMO, n (%) | 61 (80) | 33 (85) | 28 (76) | 0.33 |
| Number of sessions | 2 (1–4) | 2 (1–4) | 3 (0.5–5) | 0.51 |
| Outcomes | ||||
| ECMO weaning, n (%) | 45 (59) | 38 (97) | 7 (19) | < 0.001 |
| MV duration (days) | 41 (27.5–54.5) | 41 (29–57) | 41 (25–53) | 0.23 |
| Complications occurred during the ECMO period, n (%) | ||||
| Intravascular hemolysis | 34 (45) | 14 (37) | 20 (54) | 0.13 |
| Severe bleeding | 42 (57) | 11 (29) | 31 (86) | < 0.001 |
| Clogged circuit | 11 (15) | 6 (16) | 5 (14) | 0.82 |
| Infection | ||||
| Ventilatory-acquired pneumonia | 45 (61) | 19 (50) | 26 (72) | 0.05 |
| Bacteremia | 33 (44) | 16 (42) | 17 (46) | 0.74 |
| Septic shock | 45 (61) | 16 (36) | 29 (64) | 0.001 |
| CMV reactivation | 32 (43) | 13 (34) | 19 (53) | 0.16 |
| CMV pneumonia | 22 (29) | 9 (23) | 13 (35) | 0.25 |
| HSV reactivation | 21 (28) | 9 (24) | 12 (33) | 0.44 |
| HSV pneumonia | 14 (18) | 6 (15) | 8(22) | 0.56 |
| Arterial or venous thrombosis | 36 (47) | 27 (69) | 9 (24) | < 0.001 |
| Deep vein thrombosis or pulmonary thrombosis | 34 (45) | 26 (67) | 8 (22) | < 0.001 |
| Heparin-induced thrombocytopenia | 3 (4) | 3 (8) | 0 | 0.08 |
| Circuit change | 30 (39) | 13 (33) | 17 (46) | 0.26 |
| Number of circuit change | 0 (0–1) | 0 (0–1) | 0 (0–1) | 0.02 |
| Renal replacement therapy | 25 (33) | 8 (20) | 17 (68) | 0.02 |
Data are expressed as median (interquartiles) or number (percentage, %). Obesity was defined by a BMI superior or equal to 30 g/m2
Mechanical power (MP) was calculated as follows: MP = 0.098 × tidal volume × respiratory rate × (peak pressure − ½ × driving pressure). Driving pressure was defined as plateau pressure minus positive end-expiratory pressure. Static compliance was defined as tidal volume divided by driving pressure
BMI: body mass index; NSAID: non-steroidal anti-inflammatory drug; ACE: angiotensin converting enzyme; ARB: angiotensin II receptor blockers; SAPS II: Simplified Acute Physiology score; SOFA: Sequential Organ Function; ICU: intensive care unit; ECMO: extra-corporeal membrane oxygenation; MV: mechanical ventilation; O2: oxygen; PaO2: partial pressure of arterial oxygen; FiO2: fraction of Inspired oxygen; PaCO2: partial pressure of arterial carbon dioxide; PaO2/FiO2: ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen; RESP score [17]: Respiratory Extracorporeal Membrane Oxygenation Survival Prediction Score; ECMO net score [18]: score from the Italian ECMO network; PRESERVE score [19]: PRedicting dEath for SEvere ARDS on VV-ECMO score
a3 patients had missing data for BMI
bPatients receiving dexamethasone 6 mg per day or equivalent dose of corticosteroids