Lower tidal volume ventilation by ECCO2R does not reduce mortality in respiratory failure: JAMA

UK: The use of extracorporeal carbon dioxide removal to facilitate lower tidal volume ventilation versus standard care ventilation does not significantly reduce 90-day mortality in patients with acute hypoxemic respiratory failure, a recent study has revealed. The study is published in the Journal of the American Medical Association (JAMA). 

Acute hypoxemic respiratory failure is associated with significant mortality and long-term morbidity for survivors and is a leading cause of admission to intensive care units (ICUs). Invasive mechanical ventilation following tracheal intubation is often used as a life-saving intervention for maintaining adequate gas exchanges but contributes to overall mortality and morbidity of this condition. 

Ventilation with a lung-protective strategy aiming for a tidal volume of 6 mL/kg predicted body weight and a plateau pressure less than or equal to 30 cm H2O in patients is one of the few interventions shown to reduce mortality in patients with acute hypoxemic respiratory failure and ARDS. However, lung hyperinflation and injury can still occur even when using lung-protective invasive mechanical ventilation. Further reduction in tidal volume may cause more adverse effects such as altered cardiac function and pulmonary hypertension. 

Extracorporeal gas exchange, including extracorporeal carbon dioxide removal (ECCO2R), can facilitate mechanical ventilation even with lower tidal volume as its supports carbon dioxide removal. 

Against the above background, James J. McNamee, Queen's University Belfast, Belfast, United Kingdom, and colleagues aimed to determine whether lower tidal volume ventilation facilitated by ECCO2R compared with standard care in patients with acute hypoxemic respiratory failure decreased mortality 90 days after randomization in REST -- a multicenter, randomized, allocation-concealed, open-label, pragmatic clinical trial. 

The trial enrolled 412 adult patients receiving mechanical ventilation for acute hypoxemic respiratory failure, of a planned sample size of 1120, between May 2016 and December 2019 from 51 intensive care units in the UK. Follow-up ended on March 11, 2020.

Participants were randomized to receive lower tidal volume ventilation facilitated by extracorporeal carbon dioxide removal for at least 48 hours (n = 202) or standard care with conventional low tidal volume ventilation (n = 210).

The trial was stopped early because of futility and feasibility following recommendations from the data monitoring and ethics committee.

"The use of extracorporeal carbon dioxide removal to facilitate lower tidal volume mechanical ventilation among patients with acute hypoxemic respiratory failure, compared with conventional low tidal volume mechanical ventilation, did not significantly reduce 90-day mortality," wrote the authors.

"They concluded, "due to early termination, the study may have been underpowered to detect a clinically important difference."

Reference:

The study titled, "Effect of Lower Tidal Volume Ventilation Facilitated by Extracorporeal Carbon Dioxide Removal vs Standard Care Ventilation on 90-Day Mortality in Patients With Acute Hypoxemic Respiratory Failure: The REST Randomized Clinical Trial," is published in JAMA.

DOI: https://jamanetwork.com/journals/jama/fullarticle/2783809