Ultra-protective Pulmonary Ventilation Supported by Low Flow ECCO2R for Severe ARDS (U-Protect)

Ultra-protective Pulmonary Ventilation Supported by Low Flow Extracorporeal Carbon Dioxide Removal (ECCO2R) and Prone Positioning for ARDS; a Pilot Study.

This study evaluates the use of ultra-protective ventilation, where very low ventilation volumes are used, in patients with severe acute respiratory distress syndrome (ARDS) meeting criteria to nurse in the prone position. Half the patients will receive ultra-protective ventilation support by extracorporeal carbon dioxide removal, while the other half will receive conventional lung protective ventilation.

Current best practices for management of severe ARDS include lung protective ventilation and nursing in the prone position. However, the best lung protective strategy is not currently established and using smaller ventilation volumes than standard lung protective ventilation suggest lung recovery is improved. Application of smaller ventilation volumes requires extracorporeal carbon dioxide removal, using a device similar to a dialysis to remove carbon dioxide directly from the blood. One such device in the Prismalung, it removes blood through a catheter, much like a dialysis catheter, pumps it through a gas exchange cartridge which removes carbon dioxide. The gas exchange cartridge functions in a similar way to a dialysis filter, except it allow gases to pass through, unlike dialysis filters which allow passage of fluid and small molecules.

Lung protective ventilation (6ml/kg predicted body weight). All other interventions per intensive care unit standardised ARDS management protocol

Ultra-protective ventilation (</= 3ml/kg predicted body weight) targeting plateau pressure of </= 25 cmH2O, supported by Prismalung. All other intervention per intensive care unit standardised ARDS management protocol

Prism lung (Baxter Healthcare/Gambro Lund, Sweden) is an extracorporeal carbon dioxide removal device. It removes blood through a double lumen catheter and pumps it through a hollow fiber gas exchange cartridge which is impervious to fluid. Carbon dioxide diffuses out, down a concentration gradient which is maintained by sweep gas flowing through the centre of the hollow fibres. The decarboxylated blood is returned to the patient through the double lumen catheter.

Echocardiogram data will be collected before prone position, after prone positioning and following initiation of ultra-protective ventilation

Inclusion Criteria: Admitted to MICU with respiratory failure and intubated ARDS criteria per Berlin definition PaO2:FiO2 ratio ≤ 200 mmHg for > 6 hours with FiO2 ≥0.5 Expected to require mechanical ventilation for >48 hours Reversible disease Exclusion Criteria: Anticoagulation contraindicated Proven HIT Unable to obtain central venous access Refractory hypoxia (PaO2:FiO2 ≤80 after recruitment and proning) or other indication for ECMO Home oxygen use Severe COPD Interstitial lung disease > 7 days of mechanical ventilation Immunocompromised patient (bone marrow, untreated HIV, PJP) Advanced malignancy with life expectancy ≤ 6months

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. doi: 10.1097/ALN.0b013e3181b764d2.

Bein T, Weber-Carstens S, Goldmann A, Muller T, Staudinger T, Brederlau J, Muellenbach R, Dembinski R, Graf BM, Wewalka M, Philipp A, Wernecke KD, Lubnow M, Slutsky AS. Lower tidal volume strategy ( approximately 3 ml/kg) combined with extracorporeal CO2 removal versus 'conventional' protective ventilation (6 ml/kg) in severe ARDS: the prospective randomized Xtravent-study. Intensive Care Med. 2013 May;39(5):847-56. doi: 10.1007/s00134-012-2787-6. Epub 2013 Jan 10.