SHAKEN, NOT STIRRED: HIGH FREQUENCY PERCUSSIVE VENTILATION AS A SALVAGE THERAPY IN SEVERE ARDS DUE TO COVID-19

Abstract

TOPIC: Critical Care TYPE: Original Investigations PURPOSE: The Covid-19 pandemic has necessitated alternative strategies to treat severe Acute Respiratory Distress Syndrome (ARDS) and refractory hypoxemia. High frequency percussive ventilation (HFPV) is delivered via a hybrid ventilatory mode merging low-frequency, time cycled and pressure-limited normal volume convective ventilation with high-frequency low-volume pulsatile ventilation. This hybrid mode of ventilation creates a countercurrent flow of air which mobilizes secretions and improves gas exchange. HFPV theoretically achieves alveolar recruitment at lower peak airway pressures compared to conventional ventilation (CV), thus reducing barotrauma and ventilator-induced lung injury. Benefit from HFPV has mainly been shown in burn patients, but it has also been used in ARDS as a rescue therapy. Here, we describe our experience with HFPV in our patients with COVID-19-related ARDS in a Northern California county hospital. METHODS: From January 2020 through March 2021, 18 patients with Covid-19-related ARDS were placed on HFPV at a public tertiary care center. Data regarding demographics, complications during HFPV, ventilation settings, P/F ratios prior to and on HFPV, and hospital outcomes was collected for these patients. RESULTS: 12 men and 6 women ranging from 31-73 years of age (mean age 57 years) with Covid-19-related ARDS utilized HFPV. All patients during their ventilatory course received inhaled nitric oxide. 78% of the patients (n=14) had P/F ratios < 100 prior to being transitioned from CV. Approximately 33% of these patients (n=6) were found to have pneumothorax or pneumo-mediastinum while on HFPV. The mean age of survivors was 51 years old, whereas the mean age of non-survivors was 62 years old. Mean duration on HFPV ventilator among survivors was 15.9 days, versus 11.5 days in non-survivors. Survival rate was 44% in our cohort (n=8), and 7 of these 8 surviving patients underwent tracheostomy. Mean length of total mechanical ventilation (CV plus HFPV) until tracheostomy or extubation in all survivors was 32.3 days. CONCLUSIONS: Our small cohort showed a survival rate of 44% when placing patients with COVID-19-related ARDS on HFPV. Despite the limitations of our study, including small sample size, lack of randomization, and the presence confounding factors effecting outcomes, our study reflects a potential role for HFPV as a therapy for refractory hypoxemia in COVID-19-related ARDS. Future studies are needed to investigate a possible role of HFPV in this population. CLINICAL IMPLICATIONS: Clinical implications of this experience and potential future studies may lead to usage of HFPV as a rescue mode of ventilation for COVID-19-related ARDS. DISCLOSURES: No relevant relationships by Umang Barvalia, source=Web Response No relevant relationships by Weichia Chen, source=Web Response No relevant relationships by Heng Duong, source=Web Response No relevant relationships by Amit Gohil, source=Web Response No relevant relationships by Eric Hsiao, source=Web Response No relevant relationships by Craig Ivie, source=Web Response No relevant relationships by Neharika Khurana, source=Web Response No relevant relationships by Vibha Mohindra, source=Web Response No relevant relationships by Halley Tsai, source=Web Response No relevant relationships by John Wehner, source=Web Response