The objective of this study is to assess the efficacy and safety of this new Prismalung+ membrane in its intended clinical setting by demonstrating a reduction in ventilatory parameters and pulmonary energy load or the successful maintenance of spontaneous breathing, respectively, the absence of the need to initiate vv-ECMO therapy, and initial survival.

Our hypotheses are that decarboxylation therapy by means of the novel Prismalung+ membrane in patients with hypercapnic respiratory failure (I) allows the reduction of tidal volume, peak airway pressure, dP and pulmonary energy load (as measured by AUC over 72 hours) as compared to baseline in mechanically ventilated patients OR is associated with successful continuation of spontaneous breathing despite respiratory exhaustion (no decision to intubate), and that these patients (II) warrant no decision to initiate vv-ECMO therapy and (III) do not experience early mortality.

The primary Objectives of the study are to test our hypotheses I to III by applying the novel Prismalung+ ECCO2R device in mechanically ventilated patients and spontaneously breathing patients experiencing hypercapnic respiratory failure in a multi-central prospective trial in three experienced intensive care units in Switzerland.

Inclusion Criteria:

• Mechanically ventilated patient: (I) Progressive respiratory failure (pH≤7.25 and/ or PaCO2 ≥9 kPa) during mechanical ventilation (II) with an inability to maintain lung protective ventilation (VT<4 mL/kg, Ppeak <30 mbar, Driving Pressure ≤12 mbar)
• OR awake spontaneously breathing patient: Respiratory exhaustion (pH≤7.25 and/or PaCO2 ≥9 kPa)
• AND Informed Consent as documented by signature

Exclusion Criteria:

• Mechanical Ventilation group: Need for v-v ECMO
• Awake spontaneously breathing group: Need for mechanical ventilation due to inability to remain un-sedated
• Thrombocytopenia (<100G/l)
• Contraindications for Heparin therapy (history of heparin antibodies, previous history of intracranial bleeding)
• Patients under 18 years of age
• Women who are pregnant or breast feeding
• Previous enrolment into the current study
• Enrolment of the investigator, his/her family members, employees and other dependent persons

Adult, mechanically ventilated critically ill patients with respiratory failure and incapacity to sustain lung protective ventilation or respiratory exhausting awake, spontaneously breathing critically ill patients