Table 1.
Pre-ECMO characteristics according to ICU admission before or after July 1, 2020
| Characteristic | All (N = 159) | ICU admission | p | |
|---|---|---|---|---|
| Before July 1 (N = 88) | After July 1 (N = 71) | |||
| Age, years | 51 (43–58) | 49 (41–56) | 54 (49–60) | 0.002 |
| Male | 114 (72) | 64 (73) | 50 (70) | 0.784 |
| Body mass index, kg/cm2 | 30.8 (27.7–35.1) | 30.3 (27.7–34.0) | 31.0 (27.2–37.0) | 0.513 |
| SAPS II | 55 (39–64) | 46 (30–57) | 61 (53–68) | < 0.001 |
| RESP score | 4 (2–5) | 4 (2–5) | 3 (2–4) | 0.020 |
| Total SOFA score | 11 (9–13) | 11 (9–13) | 11 (8–13) | 0.599 |
| Renal component ≥ 3 | 24 (15) | 15 (17) | 9 (13) | 0.795 |
| Cardiovascular component ≥ 3 | 79 (50) | 44 (50) | 35 (49) | 0.752 |
| Hematological component ≥ 3 | 4 (3) | 2 (2) | 2 (3) | 0.556 |
| Comorbidities | ||||
| Hypertension | 64 (40) | 34 (39) | 30 (42) | 0.644 |
| Diabetes | 54 (34) | 38 (43) | 26 (37) | 0.525 |
| Chronic respiratory diseasea | 24 (15) | 10 (11) | 14 (20) | 0.143 |
| Immunocompromisedb | 9 (6) | 3 (3) | 6 (8) | 0.189 |
| Time from | ||||
| First symptoms to ICU admission, days | 7 (5–10) | 7 (5–10) | 8 (5–11) | 0.452 |
| First symptoms to intubation, days | 10 (7–13) | 8 (6–11) | 11 (8–17) | < 0.001 |
| ICU admission to intubation, days | 1 (0–3) | 0 (0–1) | 3 (1–8) | < 0.001 |
| ICU admission to ECMO, days | 7 (3–9) | 6 (3–7) | 9 (4–12) | < 0.001 |
| Intubation to ECMO, days | 4 (1–7) | 4 (3–6) | 3 (1–7) | 0.115 |
| MERT retrieval on-ECMO from another hospital | 135 (85) | 66 (75) | 69 (97) | < 0.001 |
| High-flow oxygen before intubation | 75 (47) | 17 (19) | 58 (82) | < 0.001 |
| Duration, days | 4 (1–7) | 2 (0–4) | 5 (1–8) | 0.009 |
| Non-invasive ventilation before intubation | 32 (20) | 6 (7) | 26 (37) | < 0.001 |
| Duration, days | 3 (1–6) | 2 (3–4) | 3 (1–8) | 0.575 |
| Volume-assist control ventilation | 156 (98) | 88 (100) | 68 (96) | 0.094 |
| Ventilation parameters | ||||
| FiO2 | 100 (100–100) | 100 (100–100) | 100 (100–100) | 0.359 |
| PEEP, cmH2O | 12 (10–14) | 13 (12–14) | 12 (10–14) | 0.019 |
| Tidal volume, mL/kg PBW | 6.0 (5.6–6.4) | 6.0 (5.7–6.4) | 6.1 (5.5–6.3) | 0.661 |
| Respiratory rate, breaths/min | 30 (26–30) | 30 (28–30) | 30 (26–30) | 0.519 |
| Plateau pressure, cmH2O | 31 (29–32) | 31 (29–33) | 30 (30–32) | 0.717 |
| Driving pressure, cmH2O c | 19 (16–21) | 18 (16–20) | 19 (16–22) | 0.289 |
| Static compliance, mL/cmH2O | 21.5 (17.5–26.4) | 22.1 (18.1–26.5) | 20.8 (17.0–23.9) | 0.148 |
| Mechanical power, J/min d | 23.8 (20.2–27.1) | 24.9 (21.9–27.2) | 21.4 (19.2–26.4) | 0.055 |
| Ventilatory ratio | 2.7 (2.2–3.1) | 2.8 (2.3–3.3) | 2.5 (2.0–2.9) | 0.046 |
| Last blood-gas values pre-ECMO | ||||
| pH | 7.32 (7.25–7.39) | 7.32 (7.24–7.38) | 7.33 (7.26–7.41) | 0.143 |
| PaO2/FiO2 | 60 (54–69) | 60 (54–68) | 60 (54–74) | 0.601 |
| PaCO2, mmHg | 56 (49–65) | 57 (50–67) | 53 (48–63) | 0.156 |
| PaO2, mmHg | 63 (54–70) | 64 (54–71) | 63 (55–70) | 0.857 |
| Plasma bicarbonate, mmol/L | 27 (23–32) | 27 (24–32) | 27 (23–33) | 0.705 |
| Arterial lactate, mmol/L | 1.6 (1.3–2.1) | 1.6 (1.4–2.0) | 1.6 (1.3–2.4) | 0.858 |
| Laboratory values | ||||
| White-cell count, G/L | 13.0 (9.5–18.0) | 13.1 (10.0–17.1) | 12.9 (8.6–18.9) | 0.872 |
| Lymphocytes, G/L | 0.85 (0.50–1.33) | 0.96 (0.55–1.46) | 0.80 (0.50–1.14) | 0.328 |
| Dexamethasone (6 mg/day) started pre-ECMO | 74 (47) | 16 (18) | 58 (82) | < 0.001 |
| Rescue therapy pre-ECMO | ||||
| Any | 157 (99) | 86 (98) | 71 (100) | 0.503 |
| Neuromuscular blockade | 150 (94) | 83 (94) | 67 (94) | 1.000 |
| Prone positioning | 146 (92) | 82 (93) | 64 (90) | 0.487 |
| Inhaled nitric oxide or prostacyclin | 68 (43) | 31 (35) | 37 (52) | 0.032 |
| High-dose corticosteroids | 10 (6) | 6 (7) | 4 (6) | 1.000 |
| Almitrine | 1 (0.6) | 1 (1) | 0 (0) | 1.000 |
| Renal replacement therapy | 5 (3) | 4 (5) | 1 (1) | 0.381 |
| Cardiac arrest | 5 (3) | 3 (3) | 2 (3) | 1.000 |
Values are expressed as median (interquartile range) or number (%)
ECMO extracorporeal membrane oxygenation, ICU intensive care unit, MERT Mobile ECMO Retrieval Team, PaO2/FiO2 ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen, PEEP positive end-expiratory pressure, PBW predicted body weight, PaCO2 partial pressure of arterial carbon dioxide, RESP Respiratory Extracorporeal Membrane Oxygenation Survival Prediction, SaO2 arterial oxygen saturation, SAPS Simplified Acute Physiology Score, SOFA Sequential Organ-Function Assessment
aDefined as chronic obstructive pulmonary disease or asthma
bDefined as hematological malignancies, active solid tumor or having received specific anti-tumor treatment within 1 year, solid-organ transplant or human immunodeficiency virus-infected, long-term corticosteroids or immunosuppressants
cDefined as plateau pressure minus PEEP
dMechanical power (J/min) = 0·098 × tidal volume × respiratory rate × peak pressure – 1/2 × driving pressure. If not specified, peak pressure was considered equal to plateau pressure