Srisuparp Pimol, Heitschmidt Mary, Schreiber Michael D
Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
J Med Assoc Thai. 2002 Aug;85 Suppl 2:S469-78.
Inhaled nitric oxide (iNO) therapy has been demonstrated to acutely improve oxygenation in preterm infants with severe pulmonary disease. Administration of iNO to the premature infants with less severe pulmonary illness has not yet been studied extensively. Therefore, the authors performed a pilot study enrolling thirty-four premature infants with respiratory distress syndrome (RDS) within 72 hours of age, birth weight between 500-2,000 g, whose oxygenation indexes exceeded our birthweight-specific criteria. Infants were randomly assigned to either treatment with (iNO group; n = 16) or without (control group; n = 18) iNO. Inhaled NO was started at 20 ppm and weaned to 5 ppm over 24-48 hours. Routine cranial ultrasonography was performed and the occurrence of intraventricular hemorrhage (IVH) was interpreted by an attending pediatric radiologist unaware of the treatment group assignment. The study showed that the two groups were of similar birth weight (mean+/-SEM): control 901+/-73 g vs iNO 874+/-70 g; and gestational age: control 27.2+/-0.5 wk vs iNO 26.8+/-0.5 wk. Other baseline parameters between the two groups were also similar. The mean ages of the infants at the time of entry were 11.7+/-2.2 and 8.3+/-0.9 hours in the controls and iNO group. The entry oxygenation index (OI) did not differ between the two groups: control 11.9+/-2.2 vs iNO 10.8+/-1.50. After 30 minutes of iNO therapy, there was a 50 per cent increase in partial pressure of oxygen tension (PaO2) and 15 per cent reduction in OI, (p = 0.02 and p = 0.04 vs baseline, respectively). No statistical difference in the incidence of significant IVH (Grade III and IV) was detected: control 27.8 per cent; iNO 25.0 per cent. The incidence of other acute complications as well as early neonatal death, were comparable between the groups. The mean methemoglobin concentration was 1.2+/-0.5 per cent. In conclusion, these preliminary data suggest that iNO, as used in this protocol, acutely improves oxygenation without increasing significant IVH in premature infants with mild to moderate RDS. These important findings serve to justify further study of the efficacy of iNO on long term pulmonary outcome and mortality in this group of infants.
吸入一氧化氮（iNO）疗法已被证明可迅速改善患有严重肺部疾病的早产儿的氧合情况。对于患有不太严重肺部疾病的早产儿使用iNO疗法尚未进行广泛研究。因此，作者开展了一项试点研究，纳入了34例出生后72小时内、出生体重在500 - 2000克、氧合指数超过根据其出生体重制定的特定标准的呼吸窘迫综合征（RDS）早产儿。婴儿被随机分为接受iNO治疗组（iNO组；n = 16）或不接受iNO治疗组（对照组；n = 18）。吸入NO起始浓度为20 ppm，并在24 - 48小时内逐渐降至5 ppm。进行常规头颅超声检查，由一名不了解治疗组分配情况的儿科放射科主治医生解读脑室内出血（IVH）的发生情况。研究表明，两组婴儿的出生体重相似（均值±标准误）：对照组901±73克，iNO组874±70克；胎龄也相似：对照组27.2±0.5周，iNO组26.8±0.5周。两组之间的其他基线参数也相似。对照组和iNO组婴儿进入研究时的平均年龄分别为11.7±2.2小时和8.3±0.9小时。两组的初始氧合指数（OI）无差异：对照组11.9±2.2，iNO组10.8±1.50。iNO治疗30分钟后，氧分压（PaO2）增加50%，OI降低15%（分别与基线相比，p = 0.02和p = 0.04）。在显著IVH（III级和IV级）的发生率方面未检测到统计学差异：对照组为27.8%，iNO组为25.0%。两组之间其他急性并发症的发生率以及早期新生儿死亡率相当。平均高铁血红蛋白浓度为1.2±0.5%。总之，这些初步数据表明，按照本方案使用的iNO可迅速改善氧合情况，且不会增加轻度至中度RDS早产儿的显著IVH发生率。这些重要发现有助于证明进一步研究iNO对该组婴儿长期肺部结局和死亡率的疗效的合理性。
