Acute Respiratory Distress Syndrome Exacerbated by Inappropriate Use of Mechanical Insufflation-Exsufflation Following Infection in a Patient With Amyotrophic Lateral Sclerosis: A Case Report

Abstract

Mechanical insufflation-exsufflation (MI-E) is widely used to assist airway secretion clearance in patients with neuromuscular disorders such as amyotrophic lateral sclerosis (ALS). While MI-E is generally considered safe when used intermittently for cough augmentation, its prolonged and unsupervised use as a substitute for invasive ventilation is discouraged by current clinical guidelines, including those issued by the American College of Chest Physicians and the American Academy of Neurology. We report the case of a 53-year-old man with advanced ALS, diagnosed approximately 10 years earlier, who developed acute respiratory distress syndrome (ARDS) exacerbated by inappropriate use of MI-E following a recent respiratory infection. The patient had previously relied on tracheostomy invasive ventilation (TIV) but chose to suspend its use, instead employing MI-E continuously for 62 hours (28,234 cycles), based on prior positive experiences and personal preference. Upon hospital admission, the patient was diagnosed with mild ARDS, bacterial pneumonia, and influenza B infection. Although the respiratory infection was likely the primary cause of deterioration, MI-E-related pressure changes may have exacerbated pulmonary injury, particularly in the context of acute infection. Rapid improvement in gas exchange and imaging findings within 48 hours of MI-E discontinuation further supports this hypothesis. We discuss possible mechanisms linking excessive MI-E usage to lung injury, including barotrauma and negative pressure pulmonary edema. We also emphasize the importance of clearly defined device indications, structured caregiver education, and regular clinical supervision in home respiratory care. To our knowledge, this may be the first reported case of ARDS potentially resulting from the combined effects of infection and inappropriate MI-E application, highlighting the need for multidisciplinary coordination and proper device supervision in managing advanced neuromuscular respiratory failure at home.

Keywords: acute hypoxemic respiratory failure; acute respiratory distress syndrome [ards]; acute respiratory failure with hypoxia; amyotrophic lateral sclerosis – frontotemporal spectrum disorder; community aquired pneumonia; home respiratory rehabilitation; mechanical insufflation-exsufflation; multidisciplinary care approach; tracheostomy ventilation and amyotrophic lateral sclerosis; ventilator associated pneumonia.

Figure 1. Axial chest CT images on day 0 and day 21.

(A) Axial chest CT image obtained on day 0, showing bilateral pulmonary infiltrates predominantly in the posterior regions (arrows). (B) Another axial image from day 0, revealing more extensive bilateral involvement (arrows). (C) Axial chest CT image obtained on day 21, demonstrating marked resolution of infiltrates (arrows). (D) Additional axial CT image from day 21, showing further clearing of pulmonary infiltrates (arrows).

Figure 2. Coronal chest CT images on day 0 and day 21.

(A) Coronal CT image on day 0, showing extensive bilateral pulmonary infiltrates, especially in the posterior lower lung fields (arrows). (B) Coronal CT image on day 21, showing clear improvement in the extent and density of bilateral infiltrates (arrows).

Figure 3. Serial chest radiographs showing progressive resolution of ARDS.

(A) Chest radiograph on day 0, showing diffuse bilateral pulmonary opacities consistent with acute respiratory distress syndrome (ARDS) (arrows). (B) Chest radiograph on day 2, showing substantial improvement in pulmonary infiltrates following the discontinuation of continuous mechanical insufflation-exsufflation (MI-E) (arrows). (C) Chest radiograph on day 34, demonstrating near-complete resolution of infiltrates and normalization of lung fields.