Experimental and clinical studies on inhalaed nitric oxide therapy in pediatric surgery

一氧化氮（NO）已成功用于治疗肺动脉高压。我们的研究目的是探讨一氧化氮吸入治疗急性肺损伤合并肺动脉高压的效果。[1：实验研究]动物接受四种治疗中的一种：静脉注射内毒素、静脉注射胰蛋白酶、气管内盐酸和100%氧气通气。(1)吸入NO （5 ~ 20ppm）可减轻内毒素或胰蛋白酶所致的肺动脉高压。这些剂量的一氧化氮对全身血压没有影响。(2)吸入NO后各模型的形态学变化。(3)吸入一氧化氮组支气管肺泡灌洗液中性粒细胞数量明显低于未吸入一氧化氮组，表明一氧化氮抑制了细胞的聚集和粘附。(4)各组高铁血红蛋白含量均不超过1.5%。[2：临床研究]研制新生儿及儿童NO吸入系统。9例新生儿持续性肺动脉高压（PPHN）患者接受NO吸入（20 ppm 4小时和6 ppm 20小时）。9例新生儿中有8例，NO改善氧合指数20%，有效率89%。在某些情况下，吸入NO有助于体外氧合肺的脱机。综上所述，这些实验和临床研究结果表明，一氧化氮吸入治疗急性肺损伤和肺动脉高压是有效的。

Nitric oxide (NO) has been successfully used for treatment of pulmonary hypertension. The aim of our studies was to investigate the effect of NO inhalation therapy on acute lung injury associated with pulmonary hypertension.[1 : Experimental Study]The animals received one of four treatment : intravenous endotoxin, intravenous trypsin, intratracheal HCl, and ventilation with 100% oxygen. (1) Pulmonary hypertension induced by endotoxin or trypsin was attenuated by NO (5-20 ppm) inhalation. NO at these doses had no effect on systemic blood pressure. (2) Inhaled NO attenuated morphological changes in any model. (3) The number of neutrophils in bronchoalveolar lavage fluid was lower in NO inhalation group than in NO non-treated group suggesting that NO inhibited aggregation and adhesion of the cells. (4) Methemoglobin levels did not exceed 1.5% in any rabbit.[2 : Clinical Study]NO inhalation system for neonates and children was prepared. Nine patients with persistent pulmonary hypertension of neonates (PPHN) received NO inhalation (20 ppm for 4 hr and 6 ppm for 20 hr) . In 8 of 9 neonates, NO improved oxygenation index by 20% : the efficacy was 89%. In some cases, NO inhalation facilitated weaning from ECMO.In conclusion, these results of the experimental and clinical studies suggest that NO inhalation therapy is useful for acute lung injury and pulmonary hypertension.