Amyotrophic Lateral Sclerosis Identified by Failure to Wean From Mechanical Ventilation

In most cases of amyotrophic lateral sclerosis (ALS), respiratory muscle involvement is a late complication. Only 2.7% of ALS patients presenting with their first clinical symptoms in the extremities also experience respiratory symptoms. We report a case of an 81-year-old man with ALS, diagnosed by an unexplained failure to wean from mechanical ventilation. The patient was presented with acute respiratory failure, tachypnea and respiratory acidosis. Computed tomography of the chest showed large amounts of sputum in the trachea. An endotracheal tube was inserted, and the patient was placed on volume-controlled ventilation. However, in the course of recovery, he could not be weaned from mechanical ventilation, despite the absence of cardiopulmonary impairment. Having considered other causes of respiratory failure, wediagnosed ALS after a physical and neurologic examination and electrodiagnostic testing.