High-frequency oscillatory ventilation (HFOV) is a lung-protective method of mechanical ventilation that utilizes nonconventional gas exchange mechanisms to provide lung ventilation at very low tidal volumes and high frequencies [1]. It can maintain high end-expiratory lung volume without inducing overdistension, minimizing the risk of ventilator-induced lung injury (VILI) [7]. HFOV provides an alternative to conventional mechanical ventilation, which is associated with a higher risk of VILI occurrence [2,7]. It is often used as a rescue strategy when conventional mechanical ventilation has failed [2]. HFOV is a safe and effective ventilation strategy in the full spectrum of patient populations but has most frequently been used in the treatment of patients with acute respiratory distress syndrome (ARDS), those at risk for developing VILI, and neonates with respiratory failure [2,3].
High-frequency oscillatory ventilation has been associated with improved clinical outcomes when compared to conventional mechanical ventilation for patients with ARDS [3]. ARDS is characterized by acute lung inflammation, reducing the lungs’ ability to adequately oxygenate blood [3]. Patients typically require an artificial respirator in order to prevent death [3]. HFOV assists with the opening of collapsed lung tissue by providing constant positive pressure in the airway [3]. It can substantially reduce the mechanical stress and strain applied during each tidal breath, preventing further trauma to the lungs [1].
VILI results from two primary mechanisms: volutrauma and atelectotrauma [2]. It is characterized by an application of mechanical forces to the pulmonary epithelium lining the distal airways and alveoli, leading to the production of an inflammatory response within the lung that can spread through the blood to distal organs [1]. VILI can result in multisystem organ failure [1]. HFOV helps prevent VILI by reducing the risk of volutrauma [2]. By maintaining alveolar inflation at a constant airway pressure, HFOV prevents the lung “inflate-deflate” cycle while providing improved oxygenation to high-risk patients [2].
In the last two decades, high-frequency oscillatory ventilation has become an established method of treating neonates with respiratory failure [4]. Premature infants have structurally and functionally immature lungs that are predisposed to hypoxia [5]. Critically ill neonates often experience oxygen toxicity and barotrauma due to low lung volumes and ventilation-perfusion mismatch [5]. HFOV has become a widely used lung-protective strategy in neonatal respiratory failure since it is associated with improved respiratory status compared with conventional ventilation [5]. In a clinical trial that examined 500 neonates either on HFOV or a conventional ventilation strategy, infants in the HFOV treatment group were successfully extubated at an earlier age and were more likely to be alive and independently breathing by 36 weeks [5].
Lastly, here are some potential adverse effects that physicians should be aware of [2]. HFOV is not recommended in patients with intracranial hypertension and severe airflow limitation [1]. HFOV is less effective in disease processes with increased airway resistance, which can lead to air trapping and hyperinflation and result in barotrauma [2]. Cardiovascular function must be closely monitored as there is risk of decreased venous return, reduced cardiac output, intraventricular hemorrhage, and increased intrathoracic pressure [2]. Patients on HFOV should also be monitored for sepsis since intubation increases the likelihood of bacterial infection in the bloodstream [6].
References
- Sklar, M., Fan, E., & Goligher, E. (2017). High-Frequency Oscillatory Ventilation in Adults With ARDS. Chest, 152(6), 1306-1317. doi:10.1016/j.chest.2017.06.025
- Meyers, M., Rodrigues, N., & Ari, A. (2019). High-frequency oscillatory ventilation: A narrative review. Canadian Journal of Respiratory Therapy, 55, 40-46. doi:10.29390/cjrt-2019-004
- Sud, S., Sud, M., Friedrich, J. et al. (2016). High-frequency oscillatory ventilation versus conventional ventilation for acute respiratory distress syndrome. Cochrane Database of Systematic Reviews. doi:10.1002/14651858.cd004085.pub4
- Keszler, M., & Durand, D. (2001). Neonatal High-Frequency Ventilation. Clinics in Perinatology, 28(3), 579-607. doi:10.1016/s0095-5108(05)70108-1
- Bouchut, J., Godard, J., Claris, O., & Weiskopf, R. (2004). High-frequency Oscillatory Ventilation. Anesthesiology, 100(4), 1007-1012. doi:10.1097/00000542-200404000-00035
- Briggs, S., Goettler, C., Schenarts, P. et al. (2009). High-Frequency Oscillatory Ventilation as a Rescue Therapy for Adult Trauma Patients. American Journal of Critical Care, 18(2), 144-148. doi:10.4037/ajcc2009303
- Imai, Y., & Slutsky, A. (2005). High-frequency oscillatory ventilation and ventilator-induced lung injury. Critical Care Medicine, 33, 129-134. doi:10.1097/01.ccm.0000156793.05936.81