Liu Guo-Sheng, Wu Hui, Wu Ben-Qing, Huang Run-Zhong, Zhao Li-Hua, Wen Yan
Department of Pediatrics, First Affiliated Hospital, Jinan University, Guangzhou, China.
World J Pediatr. 2008 Feb;4(1):31-5. doi: 10.1007/s12519-008-0006-x.
Phototherapy may have an adverse effect on the hemodynamics of preterm infants, and endothelin (ET) and nitric oxide (NO) are both the powerful vasoactive substances. This study was designed to observe the effect of phototherapy on blood levels of ET and NO in preterm infants.
Sixty-four preterm infants with hyperbilirubinemia requiring phototherapy were studied. Among them, 31 patients were born at 32-36 weeks' gestational age (GA), and 33 patients were < or =32 weeks GA. Control group included 26 full-term infants with hyperbilirubinemia requiring phototherapy. All patients were treated with continuous phototherapy for 24 hours. Blood samples were collected before and after phototherapy. The amount of ET in the blood samples was determined by radioimmunoassay, and NO levels were determined using nitrate reductase. Heart rate, respiratory rate, apnea, and mean arterial blood pressure (MABP) were monitored regularly (defined interval: hourly, 4 hours, etc) during phototherapy.
Blood ET levels measured after 24 hours of phototherapy were higher than the pretreatment values, as were blood NO levels measured after 12 hours and 24 hours of phototherapy. Both increases were statistically significant (P<0.05) in the GA< or =32 weeks group. In the GA>32 weeks group, blood NO levels measured after 24 hours of phototherapy were higher than the pretreatment values; these changes were also statistically significant (P<0.05). In the GA<32 weeks group, heart rate increased and the MABP decreased during phototherapy. The changes after 24 hours of phototherapy compared to the pretreatment values were statistically significant. A few episodes of apnea occurred during phototherapy in the GA< or =32 weeks group. This was significantly higher than that in the other two groups.
Under phototherapy, blood levels of ET and NO were significantly higher in preterm infants, especially in preterm infants of < or =32 weeks GA.
光疗可能对早产儿的血流动力学产生不利影响，而内皮素（ET）和一氧化氮（NO）均为强大的血管活性物质。本研究旨在观察光疗对早产儿血液中ET和NO水平的影响。
对64例需要光疗的高胆红素血症早产儿进行研究。其中，31例患者胎龄为32 - 36周，33例患者胎龄≤32周。对照组包括26例需要光疗的高胆红素血症足月儿。所有患者均接受连续24小时光疗。在光疗前后采集血样。采用放射免疫分析法测定血样中ET的含量，用硝酸还原酶法测定NO水平。在光疗期间定期（规定间隔：每小时、4小时等）监测心率、呼吸频率、呼吸暂停及平均动脉血压（MABP）。
光疗24小时后测得的血ET水平高于治疗前值，光疗12小时和24小时后测得的血NO水平也高于治疗前值。在胎龄≤32周组，这两种升高均具有统计学意义（P<0.05）。在胎龄>32周组，光疗24小时后测得的血NO水平高于治疗前值；这些变化也具有统计学意义（P<0.05）。在胎龄<32周组，光疗期间心率增加而MABP降低。光疗24小时后的变化与治疗前值相比具有统计学意义。在胎龄≤32周组，光疗期间出现了几次呼吸暂停。这明显高于其他两组。
在光疗情况下，早产儿尤其是胎龄≤32周的早产儿血液中ET和NO水平显著升高。
