Table 1.
Characteristics of survivors and nonsurvivors of severe ARDS patients with ECMO support
| Characteristic | All patients (n = 158) | Survivors (n = 71) | Nonsurvivors (n = 87) | p value |
|---|---|---|---|---|
| Age (years) | 50.3 ± 16.3 | 46.0 ± 16.5 | 53.8 ± 15.4 | 0.003 |
| Male (gender) | 108 (68.4%) | 48 (67.6%) | 60 (69%) | 0.855 |
| Body weight (kg) | 68.5 ± 16.7 | 70.1 ± 17.4 | 67.1 ± 16.1 | 0.268 |
| Body mass index (kg/m2) | 25.8 ± 5.2 | 26.0 ± 5.8 | 25.6 ± 4.7 | 0.656 |
| ARDS etiologies | ||||
| Bacterial pneumonia | 55 (34.8%) | 19 (26.8%) | 36 (41.4%) | 0.055 |
| Viral pneumonia | 24 (15.2%) | 13 (18.3%) | 11(12.6%) | 0.327 |
| Nonpulmonary sepsis | 21 (13.3%) | 4 (5.6%) | 17 (19.5%) | 0.017 |
| Pulmonary contusion | 19 (12%) | 13 (18.3%) | 6 (6.9%) | 0.028 |
| Aspiration pneumonia | 11 (7%) | 8 (11.3%) | 3 (3.4%) | 0.066 |
| Other causes | 28 (17.7%) | 14 (19.7%) | 14 (16.1%) | 1.0 |
| Comorbidities | ||||
| Diabetes mellitus | 40 (25.3%) | 23 (32.4%) | 17 (19.5%) | 0.065 |
| Cerebrovascular accident | 10 (6.3%) | 6 (8.5%) | 4 (4.6%) | 0.346 |
| Chronic heart diseasea | 55 (34.8%) | 23 (32.4%) | 32 (36.8%) | 0.565 |
| Chronic lung diseaseb | 16 (10.1%) | 4 (5.6%) | 12 (13.8%) | 0.115 |
| Chronic liver diseasec | 22 (13.9%) | 6 (8.5%) | 16 (18.4%) | 0.073 |
| Chronic kidney diseased | 18 (11.4%) | 8 (11.3%) | 10 (11.5%) | 0.964 |
| Immunocompromisede | 42 (26.6%) | 11 (15.5%) | 31 (35.6%) | 0.004 |
| APACHE II score | 23.4 ± 7.5 | 21.8 ± 8.0 | 24.7 ± 6.9 | 0.014 |
| SOFA score | 10.9 ± 3.2 | 10.3 ± 3.1 | 11.4 ± 3.2 | 0.042 |
| Lung injury score | 3.37 ± 0.44 | 3.44 ± 0.43 | 3.32 ± 0.45 | 0.085 |
| ARDS duration before ECMO (h) | 28.0 (7.0–129.0) | 9.8 (3.7–64.0) | 54.0 (16.0–200.0) | <0.001 |
| Pre-ECMO ventilator settings | ||||
| PaO2/FiO2 (mmHg) | 64 (52–87) | 64 (53–80) | 63 (52–107) | 0.198 |
| Tidal volume (ml/kg PBW) | 7.7 ± 2.4 | 7.7 ± 2.3 | 7.8 ± 2.4 | 0.753 |
| PEEP (cm H2O) | 12.0 ± 2.8 | 12.2 ± 2.5 | 11.8 ± 3.0 | 0.319 |
| Peak inspiratory pressure (cm H2O) | 33.9 ± 6.5 | 33.6 ± 6.0 | 34.1 ± 6.8 | 0.645 |
| Mean airway pressure (cm H2O) | 18.7 ± 4.4 | 18.4 ± 4.2 | 18.9 ± 4.6 | 0.539 |
| Dynamic driving pressure (cm H2O) | 21.9 ± 6.2 | 21.1 ± 5.8 | 22.6 ± 6.5 | 0.139 |
| Dynamic compliance (ml/cm H2O) | 22.5 ± 11.2 | 23.4 ± 11.6 | 21.7 ± 10.9 | 0.366 |
| Pre-ECMO blood gas | ||||
| pH | 7.28 ± 0.14 | 7.27 ± 0.12 | 7.28 ± 0.15 | 0.842 |
| PaCO2 (mmHg) | 52.2 ± 18.8 | 50.7 ± 19.6 | 53.5 ± 18.2 | 0.359 |
| PaO2 (mmHg) | 73.3 ± 39.3 | 71.6 ± 39.2 | 74.8 ± 39.6 | 0.617 |
| Saturation (%) | 84.4 ± 15.9 | 84.7 ± 12.7 | 84.1 ± 18.2 | 0.804 |
| Ventilator settings from day 1 to 3 on ECMO | ||||
| PaO2/FiO2 (mmHg) | 178 (131–240) | 200 (146–247) | 165 (124–212) | 0.588 |
| Tidal volume (ml/kg PBW) | 6.0 ± 2.2 | 6.1 ± 2.0 | 6.0 ± 2.4 | 0.914 |
| PEEP (cm H2O) | 12.0 ± 3.3 | 12.3 ± 3.2 | 11.7 ± 3.3 | 0.202 |
| Peak inspiratory pressure (cm H2O) | 31.7 ± 5.6 | 30.6 ± 5.1 | 32.8 ± 5.9 | 0.018 |
| Mean airway pressure (cm H2O) | 17.7 ± 4.0 | 17.4 ± 3.6 | 17.9 ± 4.3 | 0.406 |
| Dynamic driving pressure (cm H2O) | 19.8 ± 6.3 | 18.3 ± 6.0 | 21.1 ± 6.4 | 0.006 |
| Dynamic compliance (ml/cm H2O) | 19.2 ± 8.1 | 21.1 ± 7.7 | 17.4 ± 8.1 | 0.006 |
| Duration of ECMO (days) | 9.0 (4.8–14.6) | 8.7 (5.0–13.0) | 9.8 (4.7–16.1) | 0.696 |
| ECMO complications | 43 (27.2%) | 16 (22.5%) | 27 (31.0%) | 0.232 |
Data are presented as mean ± standard deviation, count or median (interquartile range)
APACHE Acute Physiology and Chronic Health Evaluation, ARDS acute respiratory distress syndrome, ECMO extracorporeal membrane oxygenation, FiO 2 fraction of inspired oxygen, PaCO 2 partial pressure of carbon dioxide in arterial blood, PaO 2 partial pressure of oxygen in arterial blood, PBW predicted body weight, PEEP positive end-expiratory pressure, SOFA Sequential Organ Failure Assessment. Dynamic driving pressure: (peak inspiratory pressure—PEEP)
aChronic heart disease included chronic heart failure, valvular heart disease, arrhythmia, hypertension and coronary artery disease
bChronic lung disease included chronic obstructive pulmonary disease, interstitial lung disease, tuberculosis and bronchiectasis
cChronic liver disease included chronic hepatitis and cirrhosis
dChronic kidney disease included chronic renal insufficiency with creatinine level above 1.5 mg/dl
eImmunocompromised included hematological malignancies, solid tumors, sold organ transplantation, long-term steroid or immunosuppressant use and human immunodeficiency virus infection