Table 2.
Characteristics of the main studies that evaluated the use of venous extracorporeal membrane oxygenation in patients with acute respiratory distress syndrome
| Author | N | Design | Inclusion criteria | Exclusion criteria | Primary outcome | Main findings | Considerations |
|---|---|---|---|---|---|---|---|
| Combes et al.(1) | 249 | International multicenter, randomized, controlled clinical trial | 1. Patient intubated on MV < 7 days 2. PaO2/FiO2 < 50mmHg for > 3 hours OR PaO2/FiO2 < 80mmHg for > 6 hours OR Arterial pH < 7.25 with PaCO2 ≥ 60mmHg > 6 hours 3. Optimized MV* 4. Age >18 years |
1. Pregnant women 2. BMI > 45 3. Chronic respiratory failure 4. Indication for VA-ECMO 5. History of HIT 6. Advanced cancer 7. Dying patients 8. Coma after cardiac arrest 9. Nonreversible neurologic injury 10. Palliative patients |
60-day mortality of 35% (44/124 patients) in the ECMO group and 46% (57/125 patients) in the control group (RR: 0.76; 95%CI 0.55 -1.04; p = 0.09) | The ECMO group had a higher incidence of severe thrombocytopenia and bleeding requiring transfusion. The ECMO group had a lower incidence of IS, lower need for renal replacement therapy, and reduction of tidal volume, plateau pressure and drive pressure |
Early interruption of the study due to futility Slow recruitment rate High crossover rate (28%) from the control group to the ECMO group due to refractory hypoxemia Greater failure of treatment at 60 days in the control group |
| Peek et al.(2) | 180 | Multicenter, randomized, controlled clinical trial | 1. Age from 18 - 65 years 2. Severe but potentially reversible respiratory failure 3. Murray score ≥ 3.0 4. Uncompensated hypercapnia 5. Optimized MV |
1. PIP > 30cmH2O 2. FiO2 > 80% 3. Time of MV ≥ 7 days 4. Intracranial bleeding 5. Contraindication to heparinization 6. Limitation of support |
6-month mortality after randomization or before hospital discharge of 37% (33/90) in the ECMO group and 53% (46/87) in the control group (RR: 0.69; 95%CI 0.05-0.97, p = 0.03) | The transfer of patients with severe but potentially reversible respiratory failure to a reference center in ECMO proved to be cost-effective and reduce mortality | Control group does not have standardization of MV parameters Of the 90 patients randomized to receive ECMO, 22 patients did not use the device |
| Morris et al.(3) | 40 | Dual-center, randomized, controlled clinical trial | 1. PaO2 < 50mmHg for 2 hours with FiO2 = 100%, PEEP > 5 and PaCO2 of 30 - 45 or PaO2 < 50mmHg for 12 hours with FiO2 = 60%, PEEP ≥ 5cmH2O and PaCO2 of 30 - 45 2. Optimized MV |
1. Contraindication to anticoagulants 2. POAP > 25mmHg 3. Time of MV> 21 days 4. Severe, irreversible and without treatment prospective systemic disease. |
30-day survival of 33% (7/21) in the ECMO group and 42% (8/19) in the control group (p = 0.8) | Does not recommend the use of ECMO in patients with ARDS | Small sample size High mortality rate (62% of patients died) Technical limitations inherent to the clinical trial period Nonprotective MV in both groups |
| Zapol et al.(4) | 90 | Multicenter, randomized, controlled clinical trial | 1. PaO2 < 50 mm Hg, for more than 2 hours with FiO2 100% and PEEP ≥ 5cmH2O OR PaO2 < 50 mm Hg, for more than 12 hours with FiO2 = 60% and PEEP ≥ 5cmH2O | 1. Age from 12 to 65 years old 2. Pulmonary lesion time > 21 days 3. PWP > 25mmHg 4. Severe, irreversible and incurable systemic disease. |
30-day survival of 9.5% (4/42) in the ECMO group and 8.3% (4/48) in the control group (no significant difference) | ECMO was able to provide respiratory support, but did not increase the survival in patients with severe ARDS | Mortality in both groups greater than 90% Technical limitations inherent to the clinical trial period Nonprotective MV in both groups |
MV - mechanical ventilation; PaO2 - partial pressure of oxygen; FiO2 - fraction of inspired oxygen; PaCO2 - partial pressure of carbon dioxide; BMI - body mass index; VA-ECMO - venoarterial extracorporeal membrane oxygenation; HIT - heparin-induced thrombocytopenia; RR - relative risk; 95%CI - 95% confidence interval; IS - ischemic stroke; PIP - peak inspiratory pressure; PEEP - positive end-expiratory pressure; PWP - pulmonary wedge pressure; ARDS - acute respiratory distress an inspired fraction of oxygen ≥ 0.80 syndrome.
*
Defined by the presence of, positive end-expiratory pressure ≥ 10cmH2O and tidal volume of 6mL/kg of predicted weight.