Table 1.

List of recommended national clinical criteria for early patient centralization and for ECMO eligibility

Recommended criteria for early patient centralization

From primary and secondary hospitals to tertiary hospitals with ARDS treatment experience

Suspected H1N1 infection with one of the following:

1. Need for invasive mechanical ventilation with PEEP

2. FiO2 > 0.6

From any non-ECMO center to ECMOnet centers

Suspected H1N1 infection with one of the following:

1. HbO2 < 85%

2. OI > 25

3. PaO2/FiO2 < 100 with PEEP ≥ 10 cmH2O

4. Hypercapnia and respiratory acidosis with pH < 7.25

5. SvO2 or SvcO2 < 65% despite Ht > 30 and administration of vasoactive drugs

ECMO criteria

Inclusion criteria

All adult and pediatric patients with severe ARDS related to suspected influenza A(H1N1) presenting with at least one of the following criteria despite the use of available rescue therapies:

1. OI > 30

2. PaO2/FiO2 < 70 with PEEP ≥ 15 cmH2O (in patient already admitted to one of the ECMOnet centers)

3. PaO2/FiO2 < 100 with PEEP ≥ 10 cmH2O (in patients still to be transferred)

4. pH < 7.25 for at least 2 h

5. Hemodynamic instability

Exclusion criteria

Absolute

1. Intracranial bleeding or other major contraindication to anticoagulation

2. Previous severe disability

3. Poor prognosis because of the underlying disease (i.e., unresolved malignancy)

Relative

1. MV > 7 days

PEEP Positive end-expiratory pressure, FiO ₂ inspired oxygen fraction, HbO ₂ oxygenated hemoglobin, PaO ₂ /FiO ₂ arterial partial pressure of oxygen to FiO₂ ratio, OI oxygenation index (computed as FiO₂ × mean airway pressure × 100/PaO₂), MV mechanical ventilation