Critical Care and Shock

High frequency oscillatory ventilation may not rescue ARDS patients: an observational study

HFOV is a rescue mode of ventilation. Our objective was to assess usage and mortality predictors of HFOV. Observational study of ARDS patients, with data extracted from an ICU database. Analysis was carried out using SPSS version 20.0. Of 136 ARDS patients, 29.4% (40) were placed on HFOV. Use of HFOV correlated with age (38.7±14.8 vs 49.7±19.4 years, p=0.002, 95% CI 4.2, 17.8) and pulmonary insults (Chi2 value 44.3, p<0.001). Earlier placement was associated with levels of support on conventional ventilation (PIP – 0.343, p=0.029, PEEP – 0.322, p=0.043, FiO2 – 0.404, p=0.010, tidal volumes – 0.4, p=0.009). ICU mortality was 58.8% (80) with 53% in patients on conventional ventilation and 72.5% (29) in patients on HFOV. Multivariate regression identified APACHE IV (score≤70 OR 0.97, 95% CI 0.96, 0.98, p<0.001) and use of HFOV (OR 2.4, 95% CI 1.05, 5.5, p=0.038) as independent predictors of mortality. Baseline PaO2/FiO2 ratio (p=0.006), concurrent iNO (p=0.001), tidal volumes on conventional ventilation (p=0.016) and improved oxygenation (p=0.001) correlated significantly with survival. HFOV is associated with increased ICU mortality in patients with ARDS.