Study on the nitric oxide inhalation therapy to neonate

获得出生后第一天或第二天体重为1.2至1.6 kg的新生仔猪。初始麻醉诱导通过吸入乙醚进行，然后进行气管切开术。然后，静脉给予戊巴比妥钠和潘可溴铵，并开始辅助通气。通过右颈外静脉将球囊导管推入肺动脉。通过脐动脉将导管推进降主动脉。连续监测肺动脉压（PAP）和体循环动脉压（SAP）。通过降低吸入氧浓度（FiO_2=0.05 ~ 0.1）诱导肺动脉高压。(1)吸入一氧化氮可降低缺氧性肺动脉高压模型的肺动脉压，但对肺动脉压无明显影响。(2)当吸入NO浓度从1 ppm增加到5 ppm时，PAP的下降率升高，而当NO浓度从5 ppm增加到40 ppm时，PAP的下降率不变。NO浓度随着PIP水平的增加而增加。NO浓度随着沉降流量的增加而降低。同时比较了高频振荡通气（HFOV）作为机械通气模式与间歇性指令通气模式时呼吸回路中NO2的产生情况。HFOV与窄NO给药线联合应用时NO 2浓度显著升高。这是因为由振荡产生的气体的来回运动对NO给药管线中的NO和氧气产生影响。

Newborn piglets weighting 1.2 to 1.6 kg on the first or second day of life were obtained. Initial anesthetic induction was performed by inhaled ethyl ether followed by tracheotomy. Then, the pentobarbital sodium and pancronium bromide were intravenously given and assisted ventilation was started. A balloon catheter was advanced into pulmonary artery through the right external jugular vein. A catheter was advanced into descending aorta through the umbilical artery. Pulmonary arterial pressure (PAP) and systemic arterial pressure (SAP) were continuously monitored. Pulmonary hypertension was induced by reducing the inspired oxygen concentration (FiO_2=0.05 to 0.1).(1) Inhaled nitric oxide decreased PAP in piglets model of hypoxic pulmonary hypertension while they did not alter SAP.(2) The decrease rates of PAP were elevated as the concentrations of inhaled NO were increased from 1 to 5 ppm, however its were constant when the NO concentrations were increased from 5 to 40 ppm.The delivered NO concentration is affected by a change in the ventilatory setting during neonatal mechanical ventilatory support. The NO concentration was increased as the settled PIP level was increased. A decrease was seen in the NO concentration as the settled ventilatory flow was increased. The NO concentration fluctuated greatly in association with the settled ventilatory rate.And, we compared the production of nitrogen dioxide (NO2) in ventilatory circuit when high frequency oscillatory ventilation (HFOV) is used as the mode of mechanical ventilation versus intermittent mandatory ventilation. The NO2 concentrations in the combination of the HFOV and the narrow NO administration line were significant high level. This occurs because the back and forth movements of the gas generated by the oscillation had an influence on the NO and oxygen gases in the NO administration line.