Using helium-oxygen mixtures in the emergency management of acute upper airway obstruction.

Helium (80%)-oxygen (20%) mixtures (He-O2) are less dense and less viscous than room air. Respiratory work to overcome upper airway obstruction from a number of pathologic conditions may be reduced by inhaling He-O2 instead of room air. We present the case of a 23-year-old woman with a history of asthma and tracheal angioedema refractory to conventional antiasthma and even immunosuppressive therapy. She had previously required frequent intubation and mechanical ventilatory support. During the most recent episode of respiratory distress, prior to intubation as access for mechanical ventilatory support, the patient was placed on He-O2 by a nonrebreathing face mask. She improved clinically within minutes, and continuous pulse oximetry showed a rise in oxygen saturation from 91% to 98%. The patient's condition stabilized and intubation was not required during the subsequent hospitalization. He-O2 may be beneficial in certain patients with acute upper airway obstruction as a noninvasive, temporizing therapy with minimal adverse effects. We recommend close monitoring of the clinical response and the use of continuous pulse oximetry, substantiated by arterial blood gases when feasible.