The evolution of anesthesia management of patients with anterior mediastinal mass.

Anesthesia management of patients with mediastinal mass compressing the central airway is considered challenging. It is widely believed that general anesthesia induction in patients with mediastinal mass is associated with airway collapse, difficulty in ventilation and hemodynamic compromise. Additionally, several case reports and case series described patients demise after induction of general anesthesia. This has led to the strong recommendations to use inhalation induction, avoid the use of muscle relaxant and maintenance of spontaneous ventilation. Recent studies shed new light on our understanding of airway changes associated with mediastinal mass by directly visualizing and measuring the actual changes of the airway caliber and the variation in the peak inspiratory flow (PIF) and peak expiratory flow (PEF) in patients with mediastinal mass. These studies describe the changes in airway mechanics in different states e.g., awake and anesthetized, spontaneous and positive pressure ventilated with or without muscle relaxation. Interesting new findings in these recent publications show that general anesthesia with and without muscle relaxation does not worsen a pre-existing narrowing of the airway compressed by mediastinal mass. Moreover, it was discovered that the addition of positive pressure ventilation, positive end-expiratory pressure (PEEP) and muscle relaxation in an anesthetized patient were associated with improvement in the airway caliber and airflow in these patient's population. This new understanding of the mechanics of airway obstruction and the effects of anesthesia and mechanical ventilation on patients with mediastinal mass challenges our current anesthesia practices and leads us to consider a new approach to anesthetize and ventilate these patients. This article will review the past literature that led to the widely practiced current anesthesia techniques and how it is challenged with the new research. The author will also provide a new perspective and anesthesia technique that align with the new research findings for safe induction and maintenance of general anesthesia in patients with mediastinal mass.