Therapeutic application of helium-oxygen and mechanical ventilation in a child with acute myelogenous leukemia and airway obstruction.

Children with mediastinal masses can have a variety of disparate clinical presentations, including chest pain, superior vena cava syndrome, Horner syndrome, pericardial effusion, and cardiac tamponade. Nonetheless, respiratory symptoms are present in 80% of children at presentation and are the most common presenting symptom. Management of respiratory failure due to mediastinal masses is challenging because intubation-with the accompanying sedation and paralysis-is likely to worsen the respiratory failure. For this reason, any new treatments for this condition are welcome. We report the case of an intubated 2-year-old girl with respiratory failure from a mediastinal mass who was successfully weaned from mechanical ventilatory support through the use of a 70%:30% helium-oxygen admixture (heliox). We then review mediastinal masses and the biophysical rationale for use of heliox in airway narrowing.