Dynamic hyperinflation with gas trapping, a key element of the shared pathophysiology of acutely exacerbated asthma and chronic airflow obstruction (COPD), underpins the serious consequences of positive pressure ventilation-increased workload, impaired muscular efficiency, and hemodynamic compromise. Although the basic therapeutic approach to ventilatory assistance is similar for both conditions, noninvasive ventilation, high-flow nasal cannula, and positive end-expiratory pressure are predictably more effective in COPD than asthma. The expanding deployment of extracorporeal gas exchange (extracorporeal membrane oxygenation) now provides an attractive option in tertiary centers for the care of life-threatening and refractory ventilatory failure due to airflow obstruction.