Kuhlen R, Busch T, Max M, Reyle-Hahn M, Falke KJ, Rossaint R
Department of Anaesthesiology, University Hospital, Medical School, RWTH Aachen, Germany.
Crit Care. 1999;3(1):1-6. doi: 10.1186/cc298.
Nitric oxide (NO) is a very reactive agent with potentially toxic oxidation products such as nitrogen dioxide (NO2). Therefore, during NO inhalation a constant inspired concentration and accurate measurement of NO and NO2 concentrations are essential. The objective of this study was to test the NO concentrations at various positions along the inspiratory limb of the breathing circuit using a recently developed system to administer NO in phase with inspiratory flow during mechanical ventilation (Servo 300 NO-A, Siemens, Sweden). Furthermore, we tested whether an active heating system would interfere with inspired NO concentrations. RESULTS: A sharp decline in the NO concentration was found between the respirator's inspiratory outlet and more distal points along the inspiratory limb of the circuit. This finding was most evident when an active heating system was mounted between those points. CONCLUSIONS: The concentrations of NO and NO2 should be measured as near to the patient as possible, as significant fluctuations of these concentrations might be found along the inspiratory limb of the respiratory circuit especially when an active heating system is used.
一氧化氮（NO）是一种活性很强的物质，会产生具有潜在毒性的氧化产物，如二氧化氮（NO₂）。因此，在吸入一氧化氮期间，保持恒定的吸入浓度并准确测量一氧化氮和二氧化氮的浓度至关重要。本研究的目的是使用一种最近开发的系统，在机械通气期间与吸气气流同步给予一氧化氮，来测试呼吸回路吸气支不同位置的一氧化氮浓度（Servo 300 NO-A，西门子，瑞典）。此外，我们还测试了主动加热系统是否会干扰吸入的一氧化氮浓度。结果：在呼吸机吸气出口与回路吸气支更远端的点之间，发现一氧化氮浓度急剧下降。当在这些点之间安装主动加热系统时，这一发现最为明显。结论：一氧化氮和二氧化氮的浓度应尽可能在靠近患者处测量，因为在呼吸回路吸气支可能会发现这些浓度有显著波动，尤其是在使用主动加热系统时。
