Experience with high frequency oscillation ventilation during the 2009 H1N1 influenza pandemic in Australia and New Zealand

Abstract

During the 2009 H1N1 pandemic, large numbers of patients had severe respiratory failure. High frequency oscillation ventilation was used as a salvage technique for profound hypoxaemia. Our aim was to compare this experience with high frequency oscillation ventilation during the 2009 H1N1 pandemic with the same period in 2008 by performing a three-month period prevalence study in Australian and New Zealand intensive care units. The main study end-points were clinical demographics, care delivery and survival. Nine intensive care units contributed data. During 2009 there were 22 H1N1 patients (17 adults, five children) and 10 non-H1N1 patients (five adults, five children), while in 2008, 18 patients (two adults, 16 children) received high frequency oscillation ventilation. The principal non-H1N1 high frequency oscillation ventilation indication was bacterial or viral pneumonia (56%). For H1N1 patients, the median duration of high frequency oscillation ventilation was 3.7 days (interquartile range 1.8 to 5) with concomitant therapies including recruitment manoeuvres (22%), prone ventilation (41%), inhaled prostacyclins (18%) and inhaled nitric oxide (36%). Seven patients received extracorporeal membrane oxygenation, six having H1N1. Three patients had extracorporeal membrane oxygenation concurrently, two as salvage therapy following the commencement of high frequency oscillation ventilation. In 2008, no high frequency oscillation ventilation patient received extracorporeal membrane oxygenation. Overall hospital survival was 77% in H1N1 patients, while survival in patients having adjunctive extracorporeal membrane oxygenation was similar to those receiving high frequency oscillation ventilation alone (65% compared to 71%, P = 1.00). Survival rates were comparable to published extracorporeal membrane oxygenation outcomes. High frequency oscillation ventilation was used successfully as a rescue therapy for severe respiratory failure. High frequency oscillation ventilation was only available in a limited number of intensive care units during the H1N1 pandemic.