Retrospective Evaluation of Frequency and Factors Affecting Development of Tracheomalacia in Critically ill Patients with Prolonged Intubation

Abstract

There are two types of tracheomalacia (TM) as acquired and congenital. Acquired TM which is more common is the collapse of airway after expiration due to weakness of tracheal wall (1). Most common causes of acquired TM include prolonged intubation, tracheostomy, and smoking (2). Bronchoscopic visualization of dynamic airway collapse is considered by many experts the diagnostic gold standard. Historically, TM was diagnosed if there was >50 percent decrease in airway lumen size, but data from healthy volunteers has shown that this threshold was met in up to 78 percent (3). During the expiration phase, <70% constriction of initial airway diameter is normal, 70-80% constriction is "mild", 80-90% constriction is "moderate" and >90% constriction or anterior and posterior walls touch is "severe" (3). Possible risk factors include recurrent intubation, prolonged intubation, concurrent high-dose steroid therapy, and cuff pressures >25 cm H2O. The mechanism is uncertain but may include pressure necrosis, impaired blood flow, recurrent infections, mucosal friction, or mucosal inflammation (4). In patients with TM respiratory distress occur after extubation and usually these patients are re-intubated (5). A study reported TM prevalence as 12.7% (6).This study aims to identify development frequency of and factors affecting TM in critically ill patients with prolonged intubation.