Day R W, Lynch J M, White K S, Ward R M
Department of Pediatrics, Primary Children's Medical Center, Salt Lake City, UT, USA.
Pediatrics. 1996 Oct;98(4 Pt 1):698-705.
Systemic oxygenation is improved by inhaled nitric oxide therapy in some newborns with respiratory failure and pulmonary hypertension. Our results with inhaled nitric oxide were reviewed to determine factors associated with an acute improvement in systemic oxygenation.
Newborns with oxygenation indices of 25 to 40 were prospectively randomized to receive conventional therapy with or without 20 ppm inhaled nitric oxide. All newborns with oxygenation indices greater than 40 were treated with inhaled nitric oxide. Hemodynamic, blood gas, and Doppler ultrasound measurements were performed before and after 30 to 60 minutes of observation or therapy. The severity of lung disease was classified by the chest radiograph as: (1) normal or focal disease; (2) moderate diffuse disease-diffuse lung disease with well-defined heart borders; or (3) severe diffuse disease-diffuse lung opacification with indistinct heart borders.
Heart rate, blood pressure, and ductal diameters did not change. Blood gases and ductal shunting acutely improved only in patients treated with inhaled nitric oxide. Patients with normal lung fields or focal disease had the greatest degree of improvement in systemic oxygenation. Changes in oxygenation were not influenced by gestational age, baseline blood gases, the proportion of right-to-left ductal shunting, prior treatment with a surfactant, or the use of conventional or high-frequency jet ventilation. Collectively, blood gases and ductal shunting did not improve with inhaled nitric oxide in patients with lung hypoplasia or severe diffuse lung disease. Sustained improvement in oxygenation occurred in 87% of patients with oxygenation indices greater than 40 in whom oxygenation indices less than 40 acutely developed after exposure to nitric oxide, whereas 90% of patients in whom oxygenation indices less than 40 did not acutely develop were treated with extracorporeal membrane oxygenation or ultimately died.
Inhaled nitric oxide acutely improves systemic oxygenation in many newborns with respiratory failure and pulmonary hypertension. The diagnosis and chest radiograph are helpful in identifying patients who will have favorable acute responses to therapy. In patients with severe hypoxemia, the need for invasive support with extracorporeal membrane oxygenation may be determined by an acute trial of inhaled nitric oxide.
吸入一氧化氮疗法可改善一些患有呼吸衰竭和肺动脉高压的新生儿的全身氧合情况。我们回顾了吸入一氧化氮的治疗结果，以确定与全身氧合急性改善相关的因素。
将氧合指数为25至40的新生儿前瞻性随机分为两组，分别接受含或不含20 ppm吸入一氧化氮的常规治疗。所有氧合指数大于40的新生儿均接受吸入一氧化氮治疗。在观察或治疗30至60分钟前后进行血流动力学、血气和多普勒超声测量。根据胸部X光片将肺部疾病的严重程度分为：（1）正常或局灶性疾病；（2）中度弥漫性疾病——心脏边界清晰的弥漫性肺部疾病；或（3）重度弥漫性疾病——心脏边界不清的弥漫性肺实变。
心率、血压和导管直径未发生变化。仅吸入一氧化氮治疗的患者血气和导管分流情况急性改善。肺野正常或有局灶性疾病的患者全身氧合改善程度最大。氧合变化不受胎龄、基线血气、右向左导管分流比例、先前使用表面活性剂治疗或使用常规或高频喷射通气的影响。总体而言，肺发育不全或重度弥漫性肺部疾病患者吸入一氧化氮后血气和导管分流情况未改善。氧合指数大于40且在接触一氧化氮后急性出现氧合指数小于40的患者中，87%的患者氧合持续改善，而氧合指数小于40未急性出现的患者中，90%接受了体外膜肺氧合治疗或最终死亡。
吸入一氧化氮可急性改善许多患有呼吸衰竭和肺动脉高压的新生儿的全身氧合情况。诊断和胸部X光片有助于识别对治疗有良好急性反应的患者。对于严重低氧血症患者，吸入一氧化氮的急性试验可能有助于确定是否需要体外膜肺氧合的有创支持。
