低氧性呼吸衰竭新生儿呼出气一氧化氮的测定

Exhaled ntric xxide in nonates wth and wthout hypoxemic respiratory failure

目的对气管插管机械通气和自主呼吸新生儿进行呼出气一氧化氮（eNO）检测，探讨低氧性呼吸衰竭（HRF）患儿eNO的变化特点。方法HRF组为2009年12月至2010年1月，湖南省儿童医院NICU病房收治的HRF患儿，共22例，胎龄（34．8±4．2）周，出生体质量（2490±1039）g。纳入标准：出生24h内，出现与呼吸衰竭相关典型的临床生理、病理及放射影像学表现，需要气管插管机械通气治疗的患儿。对照组为2010年5～6月入住复旦大学附属儿科医院新生儿科，出生24h内，不吸氧下脉搏血氧饱和度在正常范围，无肺部弥漫性病变的新生儿，共26例；胎龄（35．6±3．6）周，出生体质量（2238±757）g。排除标准：所有病情不稳定的先天性疾病。用化学发光法测定HRF新生儿和对照组新生儿出生后1周内每日eNO，同时监测脉搏血氧饱和度（SpO2）、吸入氧分数（FiO2）等反映呼吸力学及气体交换效率的参数。两组eNO、SpO2／FiO2与eNO／（SpO2／FiO2×100）比较用Wileoxon Mann—WhitneyU检验，两变量间相关分析采用Pearson相关分析。结果出生后最初2d，HRF患儿的eNO高于对照组新生儿[第1天，（7．94-3．2）×10^-9vs．（5．8±1．8）×10^-9，P〈0．05；第2天，（8．8±3．2）×10^-9 vs．（6．0±2．4）×10^-9，P〈0．05]第3—7天，两组eNO则差异无统计学意义。SpO2／FiO2与PaO2／FiO2呈正相关（r=0．72，P〈0．01，回归方程SpO2／FiO2=160＋0．73×PaO2／FiO2）。eNO与SpO2／FiO2具有相关性（r=-0．228，P〈0．05），随着SpO2／FiO2升高，氧合功能改善，HRF新生儿的eNO下降，接近于同日龄对照组新生儿的eNO值，但是，经修正的eNO／（SpO2／FiO2×100）比值在第5—7天仍然有2倍差别。结论通过对气管插管机械通气新生儿和自主呼吸新生儿eNO检测技术应用，发现HRF患儿与非HRF新生儿的eNO水平有差异，且随着氧合改善而缩小，可以反映HRF病情进展特点。

Objective To establish a method for measuring exhaled nitric oxide （eNO） concentrations in neonates with and without hypoxemic respiratory failure （ HRF）, and to investigate the relationship between eNO and respiratory parameters in neonates with HRF. Methods Twenty- two newborn infants with HRF and 26 control neonates were included within the first 24 hours of postnatal life. Their eNO levels were detected with a rapid - response chemiluminescence analyzer daily during the first week of their postnatal life, and lung mechanics and gas exchange efficiency were monitored at the same time, such as pulse oxygen saturation （SpO2）, inspired fraction of oxygen （FiO2 ） and other parameters. Wilcoxon Mann -Whitney U tests were used to compare eNO, SpO2/FiO2 and eNO/ （SpO2/FiO2 ×100） in two groups. Pearson＇s correlation analyses were used to determine the relationships between eNO levels and indices of hypoxemic respiratory failure. Results During the first two days of postnatal life, eNO values of HRF neonates were higher than those of the control neonates [ day 1, （7.9 ±3.2 ）×10^-9 vs. （5.8 ±1.8） ×10^-9, P〈0.05; day2, （8.8±3.2）×10^-9vs. （6.0±2.4） ×10^-9, P〈0.051, butthere were no significant differences in the following days. With SpO2/FiO2 increasing, difference of eNO values between the HRF and non - HRF controls became narrowed, but there was still two fold difference of eNO/ （SpO2/FiO： ×100） on day 5 -7. Conclusions A method for measuring eNO was established and there was difference in neonates with and without HRF, which diminished with prolonged postnatal days, reflecting pathophysiological characteristics of HRF.