XXXX administration using constant-flow ventilation.

@entity137 @entity7459 @entity26 @entity6836 @entity842
@entity842 (NO) gas is known as both a vasodilator and a toxin. It can react with @entity26 to form compounds more @entity137 than itself, such as @entity7459 ( @entity6836 ). The reactions are time dependent; thus, infusing NO into breathing circuits as close to ventilated subjects as possible may help minimize @entity137 byproduct exposure. Unfortunately, flow rates commonly used with mechanical ventilation favor laminar gas flow (streaming) within the breathing circuits. Streaming could delay mixing of NO with other inhaled gases. This mixing delay may interfere with accurate monitoring and/or delivery of NO. We tested the hypothesis that streaming of NO infused by constant flow into the inspiratory limb of a constant-flow mechanical ventilation system can lead to NO concentration delivery estimate errors. We then compared the @entity6836 concentrations at the ventilator Y-piece with three different NO mixing methods: blending the gases before they reach the breathing circuit inspiratory limb, infusing NO directly into the breathing circuit inspiratory limb far enough from the Y-piece to ensure thorough mixing, and infusing NO directly into the breathing circuit inspiratory limb immediately before the gases reach an in-line mixing device placed close to the Y-piece. Our results indicate that streaming can lead to NO concentration delivery estimate errors and that these errors can be characterized by measuring NO concentration variations across the inspiratory tubing's luminal diameter. @entity6836 concentration measured at the ventilator Y-piece were dependent on NO concentrations (p < 0.0001), NO delivery methods (p < 0.0001), and interactions between NO concentrations and NO delivery methods (p < 0.0001). We conclude that gas streaming and @entity137 byproduct exposure should be considered together when choosing an NO delivery method.
