Evaluation of Inhaled Nitric Oxide Generation Systems at Altitude.

Area of Science:

• Medical Devices
• Respiratory Therapy
• Aeromedical Transport

Background:

• Inhaled nitric oxide (INO) is a selective pulmonary vasodilator used for hypoxemia and pulmonary hypertension.
• Current INO delivery relies on compressed gas cylinders, limiting its use in military aeromedical transport.
• Novel systems generating INO from room air aim to overcome these limitations.

Purpose of the Study:

• To evaluate the performance of two portable INO generation systems (LungFit PH and Odic prototype) under simulated altitude conditions.
• To determine the feasibility of using cylinder-free INO delivery systems during aeromedical transport.

Main Methods:

• Two INO generation systems were tested at ground level, 8,000 ft, and 14,000 ft simulated altitudes.
• Devices were connected to ventilators and a test lung, with INO output measured using an INOmax DS IR analyzer.
• Testing involved 24 ventilator setting combinations across different altitudes.

Main Results:

• Both devices delivered accurate INO concentrations at ground level (LungFit: 19.8 ppm, Odic: 20.6 ppm).
• Altitude significantly affected LungFit's INO delivery (16.1 ppm at 8,000 ft, 11.6 ppm at 14,000 ft).
• The Odic device maintained consistent INO delivery across altitudes (21.3 ppm at 8,000 ft, 20.4 ppm at 14,000 ft), despite some ventilator setting variations.

Conclusions:

• Cylinder-free INO generation systems show promise for aeromedical transport.
• Altitude impacts INO delivery accuracy, with the Odic device demonstrating greater stability.
• Careful monitoring is essential for safe and effective use of these devices during transport.