Background: Inhaled nitric oxide (NO) is a selective pulmonary vasodilator used\nprimarily in the critical care setting for patients concurrently supported by invasive or\nnoninvasive positive pressure ventilation. NO delivery devices interface with ventilator\nbreathing circuits to inject NO in proportion with the flow of air/oxygen through the\ncircuit, in order to maintain a constant, target concentration of inhaled NO.\nMethods: In the present article, a NO injection and mixing element is presented. The\ndevice borrows from the design of static elements to promote rapid mixing of injected\nNO-containing gas with breathing circuit gases. Bench experiments are reported to\ndemonstrate the improved mixing afforded by the injection and mixing element, as\ncompared with conventional breathing circuit adapters, for NO injection into breathing\ncircuits. Computational fluid dynamics simulations are also presented to illustrate mixing\npatterns and nitrogen dioxide production within the element.\nResults: Over the range of air flow rates and target NO concentrations investigated,\nmixing length, defined as the downstream distance required for NO concentration\nto reach within �±5 % of the target concentration, was as high as 47 cm for the conventional\nbreathing circuit adapters, but did not exceed 7.8 cm for the injection and\nmixing element.\nConclusion: The injection and mixing element has potential to improve ease of use,\ncompatibility and safety of inhaled NO administration with mechanical ventilators and\ngas delivery devices.
Loading....