Table 3 Indications and Contraindications for ECMO use in COVID‐19 patients
Items | Explanation | |
|---|---|---|
Indications | (1) Refractory ARDS despite optimal ventilation strategies (curare use, prone positioning, inhaled nitric oxide, etc.) | ① Prone positioning is strongly recommended unless clear contraindications to prone positioning, as hemodynamic instability could justify ECMO employ without previous clinical trial in prone positioning ② Inhaled nitric oxide could be considered, but it is not mandatory before using ECMO |
(2) Prolonged mechanical ventilation < 7 d | Prolonged mechanical ventilation with ventilation settings (FiO2 > 0.9, plateau pressure > 30 cmH2O) could cause irreversible lungs injury and multiple organ damage | |
(3) The use of ECMO should be considered when the risk of death is more than 50%, and should be started when the risk of death reaches or exceeds 80% | ① Mortality risk greater than 50% is measured as PaO2/FiO2 < 150 and FiO2 > 90% and/or Murray score 2–3 [62, 63]; Mortality risk greater than 80% is measured as PaO2/FiO2 < 100 and FiO2 > 90% and/or Murray score 3–4 despite optimal care for 6 h or less ② Earlier use of ECMO after respiratory failure onset (1–2 days) is more likely to benefit patients with COVID-19 | |
(4) Severe air leak syndrome | ||
(5) Complicated with severe myocarditis or cardiogenic shock | Cardiogenic shock is defined as CI < 1.8 L/min/m2 or MAP < 60 mmHg with maximum dose of vasoactive drugs (norepinephrine > 1 mcg/kg/min) or Intra-Aortic Balloon Pump | |
Con-indications | (1) Age ≥ 65 years (relative contraindications) | |
(2) Significant underlying comorbidities that cannot be recovered | Comorbidities include: CKD ≥ III, cirrhosis, dementia, advanced lung disease, uncontrolled diabetes with chronic end-organ dysfunction, severe peripheral vascular disease, severe brain dysfunction, severe damage to the central nervous system, and advanced malignant tumors | |
(3) Severe immunosuppression | Absolute neutrophil count < 0.4 × 109 /L | |
(4) Contraindications to anticoagulation | Contraindications to anticoagulation include: liver failure caused by COVID-19 combined with severe coagulopathy, major bleeding, and recent or enlarged intracranial bleeding | |
(5) Severe multiple organ failure | ||
(6) Patients who are diagnosed with acute aortic dissection | ||
(7) Inability to accept blood products |