Study on the nitric oxide inhalation therapy to neonate

出生第1天或第2天获得重1.2 ~ 1.6 kg的新生仔猪。初步麻醉诱导吸入乙醚，然后气管切开。然后静脉给予戊巴比妥钠和溴化戊溴铵，并开始辅助通气。球囊导管经右颈外静脉进入肺动脉。导管通过脐动脉进入降主动脉。连续监测肺动脉压（PAP）和全身动脉压（SAP）。降低吸入氧浓度（FiO_2=0.05 ~ 0.1）可引起肺动脉高压。(1)吸入性一氧化氮降低了仔猪缺氧肺动脉高压模型的PAP，但对SAP没有影响。(2)吸入性一氧化氮浓度从1 ppm增加到5 ppm， PAP降低率升高，而当吸入性一氧化氮浓度从5 ppm增加到40 ppm时，PAP降低率保持不变。在新生儿机械通气支持期间，一氧化氮浓度受通气环境变化的影响。一氧化氮浓度随PIP浓度升高而升高。随着沉降通气流量的增加，一氧化氮浓度降低。一氧化氮浓度随通气率的升高而波动较大。并比较了高频振荡通气（HFOV）作为机械通气模式与间歇强制通气模式下通气回路中二氧化氮（NO2）的产出量。在高视场和窄给NO线的组合中，NO2浓度显著高。这是因为由振荡产生的气体的来回运动对NO管理线中的NO和氧气产生了影响。

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.