Exhausted by persistent coughing and dyspnea, a 63-year-old man with chronic obstructive pulmonary disease was admitted to the emergency department. Initial treatment included oxygen and pharmacologic and noninvasive positive pressure ventilation (NPPV) therapy with minimal clinical improvement. In view of this situation, a gas mixture of helium-oxygen (heliox) 70%:30% was introduced into the nasal mask as an adjunct. Within 20 minutes of therapy, a marked improvement in arterial blood gases and a reduction in respiratory rate and accessory muscle use was noted. The patient expressed in a high-pitched voice that he was "breathing easier." He remained on NPPV-heliox adjunct for 80 minutes. At the end of this period, the patient was placed on a 50% Venturi oxygen mask. He was transferred to the intensive care unit, and 6 days later he was discharged from the hospital without incident.