Moon J K, Evey L W, Moon Y S, Gest A L, Gomez M R, Wearden M E
Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.
Biomed Instrum Technol. 1997 Mar-Apr;31(2):164-8.
The authors designed a low-deadspace system to deliver inhaled nitric oxide from a high-concentration (10%) source. Nitric oxide, nitrogen dioxide, and O2 concentrations were compared under simulated inhaled nitric oxide therapy (in vitro) from low (0.08%, 800 ppm) and high (10%, 100,000 ppm) sources of nitric oxide in nitrogen. O2 concentrations remained above 99% and nitrogen dioxide below 3 ppm for nitric oxide delivered at dosages up to 180 ppm from the 10% source. An acute toxicity trial (in vivo) was also performed in nine rabbits mechanically ventilated with 100% O2 for four hours. Six rabbits received 80 ppm nitric oxide from a 10% source and three control rabbits received only O2. Nitric oxide, nitrogen dioxide, and O2 concentrations were monitored in the ventilator circuit. Methemoglobin, arterial blood gases, arterial blood pressure, and heart rate were sampled every hour. At the 80-ppm nitric oxide dose, an average of 1.1 +/- 0.2 ppm of nitrogen dioxide was produced within the ventilator circuit. Arterial methemoglobin in rabbits that received nitric oxide rose by 0.5% from baseline, compared with a 0.2% rise for controls (p = 0.001). The authors conclude that inhaled nitric oxide therapy can be provided from a high-concentration source. Because this system does not reduce inspired O2 fraction, it may be more appropriate than low-source-concentration nitric oxide delivery systems for testing the efficacy of inhaled nitric oxide as an adjunct to optimal conventional medical therapy.
作者设计了一种低死腔系统，用于从高浓度（10%）气源输送吸入一氧化氮。在模拟吸入一氧化氮治疗（体外）条件下，比较了来自氮气中低浓度（0.08%，800 ppm）和高浓度（10%，100,000 ppm）一氧化氮气源的一氧化氮、二氧化氮和氧气浓度。对于从10%气源输送剂量高达180 ppm的一氧化氮，氧气浓度保持在99%以上，二氧化氮浓度低于3 ppm。还对9只机械通气4小时的兔子进行了急性毒性试验（体内）。6只兔子接受来自10%气源的80 ppm一氧化氮，3只对照兔子仅接受氧气。监测通气回路中的一氧化氮、二氧化氮和氧气浓度。每小时采集高铁血红蛋白、动脉血气、动脉血压和心率样本。在80 ppm一氧化氮剂量下，通气回路中平均产生1.1±0.2 ppm的二氧化氮。接受一氧化氮的兔子动脉高铁血红蛋白较基线升高0.5%，而对照组升高0.2%（p = 0.001）。作者得出结论，吸入一氧化氮治疗可从高浓度气源提供。由于该系统不会降低吸入氧气分数，对于测试吸入一氧化氮作为最佳传统医学治疗辅助手段的疗效而言，它可能比低气源浓度一氧化氮输送系统更合适。
