A narrative review of airway changes after prolonged use of supraglottic airway devices: Molecular mechanisms, pathophysiology, and preventive strategies

There has been an exponential increase in the use of supraglottic airway devices (SGAs) to provide a secure airway without tracheal intubation. They are widely used for many elective surgeries, rescue ventilation after failed intubation, and have been widely recommended for prehospital care. However, its use for extended periods when endotracheal intubation is not feasible may lead to tongue engorgement, mucosal injury, nerve palsy, and subsequent difficult intubation. This narrative review aims to synthesize current evidence on difficult airways and airway-related complications following prolonged use of SGA placement. Here we describe plausible mechanisms, including inflammatory and ischemic pathways, and discuss the severity patterns, risk factors, and preventive/management strategies of a possible difficult airway after prolonged use of SGA in perioperative and intensive care unit settings. Preventive strategies across concentric petals, highlighting correct SGA device and its size selection, minimal cuff inflation in devices that have a cuff, continuous monitoring of cuff pressure, early replacement with an endotracheal tube, appropriate head positioning, device replacement, humidification, and sedation. Implementing these measures can minimize the complications as well as the risk of a difficult airway after prolonged SGA use. Literature on this topic is difficult to find, and definitive recommendations need research, which should prioritize standardization and robust study designs, which may help guide practice. Mechanistic and translational research work should explore pressure-ischemia and inflammatory pathways to facilitate device design improvements and evidence-based protocols for monitoring, timing of exchange to a definitive airway, and safe removal strategies.