Table 1.
Demographic characteristics of patients before ECMO stratified for survival and non-survival
| Total (n = 108) | Survivors (n = 41) | Non-survivors (n = 67) | p value | ||||
|---|---|---|---|---|---|---|---|
| Age (years) | 48 | (37; 55) | 47 | (36; 55) | 48 | (38; 56) | 0.421 |
| Sex, male (%) | 69 | (64) | 27 | (66) | 42 | (63) | 0.739 |
| Weight (kg) | 85 | (70; 100) | 90 | (80; 103) | 82 | (70; 100) | 0.050 |
| Height (m) | 1.75 | (1.69; 1.8) | 1.75 | (1.7; 1.8) | 1.75 | (1.66; 1.8) | 0.393 |
| Body mass index (kg m–2) | 27.8 | (24.5; 32.0) | 29.3 | (26.3; 33.8) | 26.3 | (24.2; 30.9) | 0.028 |
| Immunocompromised (%)a | 41 | (38) | 11 | (26.8) | 30 | (44.8) | 0.062 |
| Cirrhosis (%) | 12 | (11.1) | 4 | (9.8) | 8 | (11.9) | |
| Solid cancer (%) | 10 | (9.3) | 2 | (4.9) | 8 | (11.9) | |
| Haematological malignancies (%) | 8 | (7.4) | 4 | (9.8) | 4 | (6.0) | |
| Long-term corticosteroids (%) | 5 | (4.6) | 0 | (0.0) | 5 | (7.5) | |
| Solid organ transplantation (%) | 3 | (2.8) | 1 | (2.4) | 2 | (3.0) | |
| AIDS (%) | 3 | (2.8) | 0 | (0.0) | 3 | (4.5) | |
| CNS dysfunction (%)b | 39 | (36.1) | 13 | (31.7) | 26 | (38.8) | 0.456 |
| Bicarbonate infusion (%) | 70 | (64.8) | 24 | (58.5) | 46 | (68.7) | 0.285 |
| Cardiac arrest (%) | 22 | (20.4) | 7 | (17.1) | 15 | (22.4) | 0.506 |
| SOFA score | 14 | (12; 16) | 13 | (11; 15) | 15 | (12; 17) | < 0.001 |
| SAPS II | 63 | (57; 73) | 60 | (56; 68) | 65 | (59; 75) | 0.009 |
| Prone positioning (%) | 53 | (49.1) | 19 | (46.3) | 34 | (50.7) | 0.657 |
| Neuromuscular blocker use (%) | 103 | (95.4) | 40 | (97.6) | 63 | (94) | 0.397 |
| Acute respiratory failure diagnostic groups | |||||||
| Bacterial pneumonia (%) | 45 | (41.7) | 20 | (48.8) | 25 | (37.3) | 0.241 |
| H1N1 pneumonia (%) | 19 | (17.6) | 7 | (17.1) | 12 | (17.9) | 0.912 |
| Pre-ECMO ventilator settings | |||||||
| PEEP (mbar) | 15 | (12; 18) | 15 | (12; 18) | 15 | (14; 18) | 0.420 |
| PIP = Pplat (mbar) | 34.5 | (30; 38) | 34 | (30.5; 35) | 35 | (30; 38) | 0.384 |
| PaO2/FiO2 (mmHg) | 72 | (58; 91) | 71 | (60; 94) | 73 | (55; 91) | 0.529 |
| FiO2 (%) | 100 | (92.5; 100) | 100 | (80; 100) | 100 | (100; 100) | 0.058 |
| Mean airway pressure (mbar) | 25 | (22; 27) | 25 | (22; 26.5) | 25 | (22; 28) | 0.231 |
| Minute ventilation (l min–1) | 9.2 | (2.6) | 9.3 | (2.6) | 9.2 | (2.6) | 0.829 |
| Respiratory rate (min–1) | 20 | (19; 24) | 20 | (19.5; 23.5) | 20 | (19; 24) | 0.860 |
| Interval MV-ECMO (h) | 37 | (17.3; 102) | 26 | (17; 84.5) | 40 | (19; 124) | 0.140 |
| Pre-ECMO blood gases | |||||||
| PaCO2 (mmHg) | 65 | (54; 84) | 66 | (46; 75) | 65 | (59; 88) | 0.201 |
| pHa | 7.20 | (0.12) | 7.24 | (0.13) | 7.17 | (0.11) | 0.005 |
| PaO2 (mmHg) | 68 | (57; 81) | 66 | (58; 80) | 69 | (55; 84) | 0.674 |
| SaO2 (%) | 91 | (85.1; 94) | 91 | (86.9; 93) | 90.6 | (85; 94.3) | 0.641 |
| Haemoglobin concentration (g dl–1) | 10.4 | (9.2; 12.0) | 10.7 | (9.6; 12.6) | 10.1 | (9.2; 11.2) | 0.115 |
| Lactate concentration (mmol l–1) | 2.8 | (1.5; 5.9) | 2.3 | (1.3; 3.4) | 4.1 | (1.6; 8.5) | 0.001 |
| Bilirubin concentration (mg dl–1) | 0.7 | (0.4; 1.4) | 0.6 | (0.4; 0.9) | 1.0 | (0.5; 1.7) | 0.035 |
| Creatinine concentration (mg dl–1) | 1.2 | (0.9; 2.2) | 1.2 | (0.9; 1.8) | 1.3 | (0.9; 2.5) | 0.168 |
| Haematocrit (%) | 33.9 | (31.3; 37) | 34 | (32; 37.7) | 32.8 | (31; 36.4) | 0.182 |
| CRP concentration (mg dl–1) | 22.9 | (15.0) | 22.4 | (16.8) | 23.1 | (13.8) | 0.811 |
| PCT concentration (ng ml–1) | 4.7 | (1.0; 24.9) | 5.4 | (0.5; 15.3) | 4.1 | (1.8; 32.7) | 0.155 |
| Platelet concentration (×1000 μl–1) | 162 | (90; 245) | 209 | (116; 286) | 139 | (69; 202) | 0.005 |
| Hemodynamic variables | |||||||
| Heart rate (min–1) | 115 | (100; 130) | 109 | (90; 120) | 120 | (103; 130) | 0.015 |
| Mean arterial pressure (mmHg) | 80 | (72; 92) | 87 | (80; 104) | 77 | (70; 87) | < 0.001 |
| Norepinephrine dosage (μg kg–1 min–1) | 0.62 | (0.22; 1.91) | 0.3 | (0.1; 0.67) | 0.95 | (0.44; 3.06) | < 0.001 |
| Pre-ECMO hospital stay (days) | 4 | (2; 9) | 3 | (1; 6) | 4 | (2; 12) | 0.060 |
| Lung injury score | 3.0 | (3.0; 3.3) | 3.0 | (2.8; 3.3) | 3.3 | (3.0; 3.5) | 0.106 |
Variables presented as mean (standard deviation) in the case of normally distributed data or as median (first quartile; third quartile) in the case of not normally distributed data
ECMO extracorporeal membrane oxygenation, CRP C-reactive protein, PCT procalcitonin, MV mechanical ventilation, SOFA Sequential Organ Failure Assessment, SAPS Simplified Acute Physiology Score, PEEP positive end-expiratory pressure, PIP peak inspiratory pressure, P plat plateau pressure, AIDS acquired immune deficiency syndrome, SaO 2 arterial oxygen saturation, CNS, central nervous system, PaO 2 partial pressure of arterial oxygen, FiO 2 fraction of inspired oxygen, PaCO 2 partial pressure of carbon dioxide
a“Immunocompromised” defined as presence of haematologic malignancies, solid tumour, solid organ transplantation, human immunodeficiency virus, long-term corticosteroid treatment, or liver cirrhosis
b“CNS dysfunction” diagnosis combined neurotrauma, stroke, encephalopathy, cerebral embolism, seizure, and epileptic syndrome