Mechanical ventilation during pregnancy using a helium-oxygen mixture in a patient with respiratory failure due to status asthmaticus.

The authors present a 15-year-old with a second trimester intrauterine pregnancy who developed respiratory failure as the result of status asthmaticus and the development of the adult respiratory distress syndrome. Mechanical ventilation was provided with a combination of oxygen and helium to facilitate gas exchange and limit peak inflating pressures. The physiologic basis for helium's potential beneficial effects on gas exchange are reviewed. Previous reports concerning the use of helium during mechanical ventilation as well as the techniques of delivery are discussed.