Patients in end-stage cardiac failure and/or respiratory failure may be started on a rescue therapy known as Extracorporeal Membrane Oxygenation (ECMO). One of the major clinical questions is how to manage the ventilator when patients are on ECMO therapy. Ventilator Induced Lung Injury (VILI) can result from aggressive ventilation of the lung during critical illness. VILI and lung injury such as Acute Respiratory Distress Syndrome (ARDS) can further increase the total body inflammation and stress, this is known as biotrauma. Biotrauma is one of the mechanisms that causes multi-organ failure in critically ill patients. One advantage of ECMO is the ability to greatly reduce the use of the ventilator and thus VILI by taking control of the patient's oxygenation and acid-base status. By minimizing VILI during ECMO we can reduce biotrauma and thus multi-organ failure. Since the optimal ventilator settings for ECMO patients are not known, we plan to study the impact of different ventilator settings during ECMO on patient's physiology and biomarkers of inflammation and injury.

Inclusion Criteria

• Patient currently on ECMO (Veno-Venous or Venous-Arterial or Venous-Arterial-Venous)
• Patient that is a potential ECMO candidate.

Exclusion Criteria

• History of Lung or Cardiac Transplantation
• Patient is not committed to full support
• Treating clinician refusal, or unwillingness to commit to controlled ventilation for at least 4-6 hours (if patient is mechanically ventilated)
• Inability to get informed consent from the patient or surrogate.

Reasonable requests for IPD will be considered by the investigators.