High-Frequency Oscillatory Ventilation (HFOV) as Primary Ventilator Strategy in the Management of Severe Acute Respiratory Distress Syndrome (ARDS) with Pneumothorax in the Setting of Trauma

Acute respiratory distress syndrome (ARDS) is estimated to affect more than 150,000 patients annually in the United States.1 Although significant advances in critical care and strategies of mechanical ventilation have led to a decrease in associated morbidity, mortality in patients with ARDS continues to be significant. Although previous studies have identified differences between the ARDS seen in trauma patients as opposed to nontrauma and medical patients, there is a paucity of data supporting different management strategies predicated on the type of patients affected by ARDS.2 ARDS observed in trauma patients may be secondary to either the initial insult (i.e., pulmonary contusion, and thoracic trauma) or secondary to delayed processes such as sepsis. During the past two decades, the ventilator treatment of ARDS has evolved to an evidence-based approach fostered by the hallmark study of the ARDS Network, centered on preventing ventilator-induced lung injury by limiting tidal volume, optimizing nutritional support, and judicious use of antimicrobial therapy and transfusion of blood products.3 Despite advances in technology and in the treatment modalities, ARDS continues to have significantly high rate of mortality with low tidal volume ventilation having been the only ventilatory strategy proven to decrease mortality. More recent advances in mechanical ventilation such as the use of airway pressure release ventilation have shown promise in reducing intensive care unit length of stay and duration of mechanical ventilation, but have failed to show consistent reductions in ARDS-related mortality. Rescue strategies for patients failing conventional and advanced modes of mechanical ventilation include the use of high-frequency oscillatory ventilation (HFOV), prone positioning, and extracorporeal membrane oxygenation all of which have been used with limited reports of success with respect to the endpoints of oxygenation and ventilation; however, they have not been shown to decrease ARDS-related mortality. HFOV does not rely on the conventional principles of gas physiology exchange; it relies on Taylor augmented dispersion of gases and other principles using tidal volume smaller than closing volume at a high frequency to oxygenate the patient. HFOV was previously thought to be an attractive strategy in the management of ARDS to minimize barotrauma and volutrauma, while maintaining high mean airway pressures to maximize alveolar recruitment. However, the largest studies to date investigating the use of HFOV in ARDS have demonstrated reductions in refractory hypoxemia but have failed to show a survival advantage over other modes of ventilation.4 Although pneumothoraces are well reported as a consequence of alveolar over-distention and barotrauma during the management of ARDS, little is reported regarding the challenges of managing the patient with ARDS in the setting of polytrauma resulting in significant pneumothorax with major air leaks compromising tidal breathing. Tidal volume loss resulting from pneumothorax with air leak presents a unique challenge during the ventilator support of chronic obstructive pulmonary disease patients, particularly when alveolar recruitment is desired in managing ARDS. Previous reports have suggested a potential role of HFOV to reduce massive air leaks after severe chest trauma in order to prevent the need for surgical intervention to control the air leaks.We report, herein, a unique case in which severe chest trauma with pneumothorax resulting in massive air leak precluded the use of conventional or advanced modes of mechanical ventilation (alveolar recruitment), and where early use of HFOV resulted in resolution of ARDS and a favorable outcome. Address correspondence and reprint requests to Corrado P. Marini, M.D., FACS, 222 Station Plaza North, Mineola, NY 10505. E-mail: cmarini@winthrop.org.