February 28, 2013
High-Frequency Oscillation in Early Acute Respiratory Distress Syndrome.
What was the research question?
Does high frequency oscillation ventilation improve mortality in patients with moderate to severe ARDS compared to conventional low tidal volume mechanical ventilation?
How did they do it?
A multicenter, randomized, controlled trial in 39 ICUs in Canada, USA, Saudi Arabia, Chile, and India.
Planned to randomize 1200 patients but the trial was stopped after 548 due to futility.
Patients with ARDS and PO2/Fio2 ratio <200, were randomized to undergo high frequency oscillation ventilation or conventional low volume mechanical ventilation.
What did they find?
In-hospital mortality was higher in the HFOV group and conventional group (47% versus 35%, RR 1.33; 95% confidence interval, 1.09 to 1.64; P=0.005).
HFOV patients received more midazolam (199 mg per day vs. 141 mg per day, P<0.001), neuromuscular blockers (83% vs. 68%, P<0.001), vasoactive drugs (91% vs. 84%, P=0.01) and for a longer period than did patients in the control group (5 days vs. 3 days, P=0.01)
Refractory hypoxemia was higher conventional group compared to HFOV group (14% vs. 7%, P=0.007).
23% of screened patients were declined by their physician’s choice
12% of patients in the control group received HFOV for refractory hypoxemia.
Stopped early with lower number of patients than anticipated.
What does it mean?
HFOV may be associated with higher rate of in-hospital in moderate to severe ARDS compared to conventional low volume ventilation with high PEEP.
HFOV dropped out of practice based on this study and the OSCAR study. Patients with refractory hypoxemia should be considered for ECMO.