Accession Number:



Correction of Altitude-Induced Changes in Performance of the Volumetric Diffusive Respirator

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Technical Report,01 May 2014,31 Oct 2016

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University of Cincinnati Cincinnati United States

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Aeromedical transport of critically ill patients requires continued, accurate performance of equipment at altitude. Changes in barometric pressure with increasing altitude are associated with alterations in gas temperature, density, and humidity that can change the performance of mechanical ventilators at altitude. The volumetric diffusive respirator VDR-4, Percussionaire, Sandpoint, ID high-frequency ventilator is used by U.S. military medical transport teams for critically ill patients with acute respiratory failure. Measured parameter settings varied widely among subjects and among individual settings at ground level and after changes were made at altitude. All 10 subjects made adjustments to the set parameters at altitude. The use of the Monitron II did not result in greater accuracy when adjusting settings. The VDR-4 is used in some circumstances with patients who have hypoxic respiratory failure despite the inability to accurately measure tidal volumes. The addition of the Monitron II monitor may help the caregiver more accurately set and monitor timing and pressure settings due to the digital readout. A method to measure and monitor tidal volumes is paramount to patient safety.

Subject Categories:

  • Medical Facilities, Equipment and Supplies

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