ARDS Prognosis Not Affected by Mechanical Ventilation Settings During ECMO

In patients with severe acute respiratory distress syndrome (ARDS), mechanical ventilation settings during the first 2 days of extracorporeal membrane oxygenation (ECMO) did not affect prognosis, according to a study published in the American Journal of Respiratory and Critical Care Medicine.

Researchers of the Ventilation Management of Patients With Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome (LIFEGARDS) study examined current ventilator management of ECMO, adjunct therapies used, treatment complications, and the effect mechanical ventilation has on 6-month mortality of patients with severe ARDS. Patients included could receive either venoarterial or venovenous ECMO for acute respiratory failure. Baseline information collected before implantation included demographics, clinical evaluations, lung capacities, concomitant therapies, and ventilator settings. Case report forms collected daily clinical assessments and ECMO variables. Follow-up lasted for 6 months.

Of the 350 patients included in the study, the mean age was 47, 65% were men, and 325 were classified with severe ARDS. Before ECMO initiation, 62% of patients were using neuromuscular blocking agents and 26% were using prone positioning. During treatment, 41% of patients used neuromuscular blocking agents and 6% used prone positioning.

After ECMO initiation, tidal volume, plateau pressure, driving pressure, mechanical power, and respiratory rate were significantly reduced during treatment (P <.001, for all). Follow-up data indicated 74% of patients weaned off ECMO, 66% survived discharge, and 61% survived ≥6 months.

Using multivariable analysis, there was no association between ventilator settings during the first 2 days of ECMO and 6-month survival rates. Older age, higher fluid balance, higher lactate, and renal replacement therapy were associated with a higher hazard of death, and higher tidal volume and lower driving pressure during ECMO were associated with a better outcome.

Limitations of this study included reduced generalizability due to selection criteria, inability to assess ARDS incidences, and only collecting 1 daily data point while not considering changes throughout the day.

The researchers concluded that using “ventilation strategy targeting [driving pressure] ≤15 cmH2O, mechanical ventilation settings during ECMO did not impact patients’ prognosis.”

Reference

Schmidt M, Pham T, Arcadipane A, et al. Mechanical ventilation management during ECMO for ARDS: an international multicenter prospective cohort [published online May 30, 2019]. Am J Respir Crit Care Med. doi:10.1164/rccm.201806-1094OC