Patients with severe lung conditions occasionally require support with a special ventilator
(breathing machine) called the High Frequency Oscillator (HFO). Effective ventilation
requires that the pressure generated by the ventilator be as high as possible but not too
high as this can damage the lungs. In patients on HFO, there is not a well defined way to
measure this pressure. We will insert a small probe into the esophagus of patients on HFO to
see if this is an accurate way to measure lung pressures for these patients. A better
understanding of these pressures could lead to improved patient care.