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Background: Nitric oxide (NO) is a strong vasodilator, selectively directed on pulmonary circulation through inhaled administration. In adult intensive care units (ICU), it is mainly used for refractory hypoxemia in mechanically ventilated patients. Several medical delivery devices have been developed to deliver inhaled nitric oxide (iNO). The main purpose of those devices is to guarantee an accurate inspiratory NO concentration, whatever the ventilator used, with NO2 concentrations lower than 0.3 ppm. We hypothesized that the performances of the different available iNO delivery systems could depend on their working principle and could be influenced by the ventilator settings. The objective of this study was to assess the accuracy of seven different iNO-devices combined with different ICU ventilators' flow-by to reach inspiratory NO concentration targets and to evaluate their potential risk of toxicity. Methods: We tested seven iNO-devices on a test-lung connected to distinct ICU ventilators offering four different levels of flow-by. We measured the flow in the inspiratory limb of the patient circuit and the airway pressure. The nitric oxide/nitrogen (NO/N2) flow was measured on the administration line of the iNO-devices. NO and NO2 concentrations were measured in the test-lung using an electrochemical analyzer. Results: We identified three iNO-device generations based on the way they deliver NO flow: "Continuous", "Sequential to inspiratory phase" (I-Sequential) and "Proportional to inspiratory and expiratory ventilator flow" (Proportional). Median accuracy of iNO concentration measured in the test lung was 2% (interquartile range, IQR -19; 36), -23% (IQR -29; -17) and 0% (IQR -2; 0) with Continuous, I-Sequential and Proportional devices, respectively. Increased ventilator flow-by resulted in decreased iNO concentration in the test-lung with Continuous and I-Sequential devices, but not with Proportional ones. NO2 formation measured to assess potential risks of toxicity never exceeded the predefined safety target of 0.5 ppm. However, NO2 concentrations higher than or equal to 0.3 ppm, a concentration that can cause bronchoconstriction, were observed in 19% of the different configurations. Conclusion: We identified three different generations of iNO-devices, based on their gas administration modalities, that were associated with highly variable iNO concentrations' accuracy. Ventilator's flow by significantly impacted iNO concentration. Only the Proportional devices permitted to accurately deliver iNO whatever the conditions and the ventilators tested. [ABSTRACT FROM AUTHOR]

Background: Terminal lung diseases such as chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH) in progression cause a large reduction in quality of life and may lead to bilateral lung transplantation (bLTx). An artificial portable lung could provide a bridge to lung transplantation, allowing patients to remain at home and mobile for longer. To advance the development of such an artificial lung, patient feedback is essential. The aim of this study is to analyze patient acceptance about an extracorporeal artificial lung and to implement these findings into the development.Methods: In collaboration with a medical device developer, we presented a portable dummy oxygenator to patients with advanced lung disease, as potential end users. Data collection in Germany and France was based on two different methods: an online questionnaire and face-to-face interviews (F2F).Results: A total of 604 participants answered the online questionnaire and 17 participants were included in the F2F interviews. The majority of participants (COPD n=140, PH n=17) were able to walk more than 1 km with a mean suffering pressure of 2.87 and 3, respectively. Six of the 17 F2F participants who could walk < 1 km were interested in an assistive device. The statistical value of Fisher's exact test for suffering pressure and desire for a portable oxygenator was 0.45.Conclusion: In patients with advanced lung disease, there is no statistically significant association between subjectively increased suffering pressure and desire for a portable oxygenator, so market introduction may be difficult. Potential end users should be implemented early in device development. Data collection via an online questionnaire combined with personal interviews has proven to be a successful approach here. [ABSTRACT FROM AUTHOR]