Pulmonary And Renal Support During Acute Respiratory Distress Syndrome (PARSA)

• Gas transfer measurement [ Time Frame: 20 min, H1, H6, H12, H24, H36, H48 and H72. ] [ Designated as safety issue: No ]
  Measurement of PO2 and PCO2 before and after the membrane oxygenation
• Arterial blood gases [ Time Frame: 20 min, H1, H6, H12, H24, H36, H48 and H72. ] [ Designated as safety issue: No ]
  Measurement of arterial blood gases
• carbon dioxide elimination (VCO2) [ Time Frame: 20 min, H1, H6, H12, H24, H36, H48 and H72. ] [ Designated as safety issue: No ]
  Measurement of carbon dioxide elimination rate at the ventilator and at the membrane oxygenator
• Respiratory mechanics and hemodynamic parameters [ Time Frame: 20 min, H1, H6, H12, H24, H36, H48 and H72. ] [ Designated as safety issue: No ]
  Measurement of respiratory mechanics and hemodynamic parameters
• Safety monitoring [ Time Frame: 20 min, H1, H6, H12, H24, H36, H48 and H72. ] [ Designated as safety issue: Yes ]

  Continuous measurement of the differential pressure across the oxygenator membrane and across the hemofilter.

  Assessment of catheter dysfunction, clotting or disruption of the extra-corporeal circuit, clotting of the oxygenator membrane or of the hemofilter.

  Assessment of patient's haemorragic or thrombotic complications.

In patients presenting with the acute respiratory distress syndrome (ARDS), mechanical ventilation with low tidal volume (6 ml/kg predicted body weight) is the current gold standard for supportive care. However, despite a relative low tidal volume, approximatively one third of patients will experienced tidal hyperinflation, a phenomenon known to induce pulmonary and systemic inflammatory response. A further reduction of the tidal volume to 4 ml/kg (PBW) will prevent pulmonary area from tidal hyperinflation. As a result, hypercarbia and respiratory acidosis are commonly observed with such very low tidal ventilation. Extra corporeal CO2 removal is one of a mean to normalize arterial CO2 tension.

Patients with ARDS also frequently develop acute renal failure which may required Renal Replacement Therapy. Some data suggests that starting early the RRT may favor outcome.

The investigators hypothesized that a strategy combining ECCOR and RRT early in the course of patients presenting ARDS and acute renal failure will allow the tidal volume to be further reduced, providing lung protection, while avoiding the arterial CO2 tension to be increased.

For this purpose, the investigators sought to investigate the safety and the efficacy of adding a neonatal oxygenator membrane within an hemofiltration circuit.

• Acute Respiratory Distress Syndrome
• Acute Renal Failure

• Terragni PP, Del Sorbo L, Mascia L, Urbino R, Martin EL, Birocco A, Faggiano C, Quintel M, Gattinoni L, Ranieri VM. Tidal volume lower than 6 ml/kg enhances lung protection: role of extracorporeal carbon dioxide removal. Anesthesiology. 2009 Oct;111(4):826-35.
• Terragni PP, Rosboch G, Tealdi A, Corno E, Menaldo E, Davini O, Gandini G, Herrmann P, Mascia L, Quintel M, Slutsky AS, Gattinoni L, Ranieri VM. Tidal hyperinflation during low tidal volume ventilation in acute respiratory distress syndrome. Am J Respir Crit Care Med. 2007 Jan 15;175(2):160-6. Epub 2006 Oct 12.

Inclusion Criteria:

• Acute Respiratory Distress Syndrome according to the AECC definition
• Acute Renal Failure according to the RIFLE definition

Exclusion Criteria:

• Age < 18 years
• PaO2/FiO2 < 100 with FIO2 = 1 and PEEP > 18 cmH2O
• DNR order or death expected within the next 3 days
• Intracranial haemorrhage or hypertension
• Heparin allergy