Ventilating the blast lung: Exploring ventilation strategies in primary blast lung injury

Abstract

Introduction Primary blast lung injury (PBLI) is the most common and fatal of all primary blast injuries. The majority of those with PBLI will require early intubation and mechanical ventilation, and thus, ventilation strategy forms a crucial part of any management plan. Methods: A comprehensive, but not systematic, PubMed and Google Scholar database search identified articles that contribute to our current understanding of ventilation strategies in PBLI for a narrative educational review. Results A PBLI ventilation strategy must strive to minimise all four of ventilator-associated lung injury (VALI), volutrauma, barotrauma and biotrauma. The three main ventilation strategies available are conventional low tidal volume (LTV) ventilation, airway pressure release ventilation (APRV) and high frequency oscillatory ventilation (HFOV). Conventional LTV ventilation together with a variable positive end-expiratory pressure (PEEP) and permissive hypercapnia has demonstrated reduced inflammation and mortality with a greater number of ventilator-free days. APRV has the potential to reduce dynamic strain, PaO2/FiO2 ratios, levels of applied mechanical power and extravascular lung water while encouraging spontaneous breathing. HFOV is able to effectively avoid VALI while curbing inflammation and histological lung injury, though not necessarily mortality. Conclusions: Presently, PBLI should largely be managed with conventional LTV ventilation alongside a variable PEEP and permissive hypercapnia with APRV and HFOV reserved as rescue strategies for where conventional LTV ventilation fails. Clinicians should additionally consider supplementing their strategy with adjunctive therapies such as prone positioning, inhaled nitric oxide and extracorporeal membrane oxygenation that may further reduce mortality and combat severe respiratory and/or cardiac failure.