A Brief Report: The Use of High-Frequency Oscillatory Ventilation for Severe Pulmonary Contusion Duane J. Funk, MD, FRCP(C), Eugenio Lujan, MD, Eugene W. Moretti, MD, MHSc, John Davies, MA, RRT, Christopher C. Young, MD, FCCM, Mayur B. Patel, MD, and Steven N. Vaslef, MD, PhD Background: Severe pulmonary con- tusions are a common cause of acute re- spiratory distress syndrome (ARDS) and are associated with significant morbidity. High frequency oscillatory ventilation (HFOV) is a ventilatory mode that em- ploys a lung protective strategy consistent with the ARDSNet low tidal volume ven- tilation strategy and may result in reduced morbidity. The objective of this report is to examine the impact of HFOV on blunt trauma patients with severe pulmonary contusions who failed or were at a high risk of failing conventional mechanical ventilation. Methods: We undertook a retrospec- tive chart review of all patients at our institution who received HFOV for severe pulmonary contusions. Patients were placed on HFOV when their mean airway pres- sure (mP aw ) surpassed 30 cm H 2 O and their FIO 2 was greater than 0.6. Baseline demographic data including injury sever- ity score (ISS), length of time requiring HFOV, total ventilator days, and inhospi- tal mortality were collected. Serial deter- minations of oxygenation index (OI) and the PAO 2 /FIO 2 ratio (P/F) were made up to 72 hours after initiation of HFOV. A lin- ear mixed model was used to analyze the slope () of the regression line of P/F ver- sus time and that of OI versus time. Results: Seventeen patients were identified who underwent HFOV for ARDS due primarily to pulmonary contu- sions. Mean ISS was 36.6, mean APACHE II score was 21.7, and the mean time be- fore initiation of HFOV was 2.0 days. P/F increased significantly after HFOV was initiated (  12.1; 95% confidence inter- val 7.9 to 16.4, p < 0.001). OI significantly decreased after HFOV implementation ( 1.8; 95% confidence interval 2.3 to 1.3, p < 0.001). Mortality rate was 17.6%. Conclusions: The early use of HFOV appears to be safe and efficacious in blunt trauma patients sustaining pulmonary con- tusions, and results in a rapid improvement in OI and the P/F ratio. Key Words: High frequency oscilla- tory ventilation, Acute respiratory distress syndrome, Pulmonary contusion, Linear mixed model. J Trauma. 2008;65:390 –395. P ulmonary contusions are common in patients experi- encing blunt thoracic trauma, occurring in up to 16% of patients. 1 They are a result of high velocity injuries, and the transfer of kinetic energy that results in their occurrence frequently causes other injuries such as rib fractures, flail chest, pneumothorax, and hemothorax. Patients who develop pulmonary contusions are more likely to develop acute respi- ratory distress syndrome (ARDS) but do not seem to have a higher mortality rate. 2–5 They also suffer from other morbid- ity issues such as increased ventilator days, increased length of ICU stay and increased incidence of pneumonia. 5,6 The etiology for the development of ARDS in these patients is multifactorial, including disruption of the alveolar capillary membrane with subsequent alveolar flooding, and the migration and activation of neutrophils causing pulmo- nary damage. 7 The ventilatory management of patients devel- oping ARDS from pulmonary contusions is complex. Static compliance is greatly reduced, and the heterogeneity of the injury places patients at risk for ventilator induced lung injury from overdistension of healthy lung units and cyclic alveolar opening and collapse. High frequency oscillatory ventilation (HFOV) is a ven- tilatory method that theoretically achieves all of the goals of the lung protective strategy used in the ARDSNet trial. 8 HFOV uses a constant mean airway pressure (mP aw ) over which small tidal volumes are superimposed at a high respi- ratory frequency. 9 Application of this constant mP aw allows maintenance of alveolar recruitment with lower peak airway pressures (limiting barotrauma) and avoiding low end expi- ratory pressures (avoiding alveolar collapse). 9 HFOV is used commonly in premature neonates and in this population has been shown to improve gas exchange, reduce histopathologic evidence of ventilator-induced lung injury and reduce levels of inflammatory mediators when compared with conventional ventilation. 10 –13 Several adult studies have also confirmed its clinical utility, but usually in association with other salvage therapies for refractory ARDS such as prone positioning and the administration of nitric oxide. 14,15 Submitted for publication May 23, 2007. Accepted for publication May 8, 2008. Copyright © 2008 by Lippincott Williams & Wilkins From the Division of Critical Care Medicine (D.J.F., E.W.M., C.C.Y.), Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina; Division of Critical Care Medicine (E.L.), Department of Anesthesiology, Naval Medical Center, San Diego, California; Adult Critical Care (J.D.), Division of Pulmonary Medicine, Duke University Medical Center, Durham, North Carolina; Section of Trauma and Critical Care (M.B.P., S.N.V.), Division of General Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina. Presented as a poster at the 20th Annual Meeting of the Eastern Association for the Surgery of Trauma, January 16 –20, 2007, Fort Meyers, Florida. Address for reprints: Steven N. Vaslef, MD, PhD, Box 102345, Duke University Medical Center, Durham, NC 27710; email: vasle001@mc.duke.edu. DOI: 10.1097/TA.0b013e31817f283f The Journal of TRAUMA  Injury, Infection, and Critical Care 390 August 2008