Association of Need for Tracheotomy With Decreasing Mechanical In-Exsufflation Flows in Amyotrophic Lateral Sclerosis
Although patients with lower motor neuron and myopathic disorders can prolong their lives by depending on continuous noninvasive ventilatory support, most patients with amyotrophic lateral sclerosis (ALS) cannot and must use tracheostomy mechanical ventilation to prolong survival. This case demonstrates that this occurs because amyotrophic lateral sclerosis patients' upper motor neuron reflex laryngeal closure and stridor cause upper airway collapse that renders mechanical insufflation-exsufflation (MIE) ineffective in expulsing airway secretions as well as for permitting continuous noninvasive ventilatory support. A decrease in MIE-exsufflation flows is a marker for a decrease in upper airway patency that renders MIE ineffective. As airway secretions accumulate and baseline oxyhemoglobin saturation decreases, tracheotomy becomes necessary for further survival. This case demonstrates an association between diminishing MIE-exsufflation flow and need to resort to tracheotomy.