足月新生儿不同程度黄疸听性脑干反应特点分析

Characteristics of auditory brainstem response in term neonates with jaundice

目的 探讨不同程度黄疸足月新生儿的听性脑干反应（ABR）特点。方法 对2010年7月至2011年4月入住我院新生儿科的黄疸（以间接胆红素增高为主）足月新生儿（除外合并缺氧缺血性脑病、颅内出血、颅内感染,机械辅助通气者）进行ABR检测,分别测定Ⅰ、Ⅲ、Ⅴ各波的潜伏期（PL）、波间期（IPL）与振幅（AMP）。并根据性别分为男、女婴两组;根据胆红素水平分为3组：轻度组≤250μmol/L,中度组251~299μmol/L,重度组≥300μmol/L。比较不同性别及不同程度黄疸新生儿的ABR特点。结果 共入选足月黄疸新生儿442例,其中男婴筛查异常率46.2%,女婴筛查异常率29.8%,差异有统计学意义（P〈0.01）。男、女婴左耳平均阈值分别为39.6 dBnHL和32.2 dBnHL,右耳平均阈值分别为38.7 dBnHL和34.3 dBnHL,男婴均高于女婴,差异有统计学意义（P〈0.01）。重度组ABR筛查异常率（40.8%）明显高于轻度组（25.0%）,差异有统计学意义（P〈0.001）,重度组与中度组（37.9%）之间、中度组与轻度组之间差异均无统计学意义（P〉0.05）;重度组双耳Ⅰ波潜伏期、Ⅴ波潜伏期和Ⅰ~Ⅴ波间期均较轻度组和中度组延长,差异有统计学意义（P〈0.01）,轻度组与中度组差异无统计学意义（P〉0.05）。结论 黄疸足月儿中男婴听力损失发生率高于女婴。胆红素影响听力不仅表现在阈值升高,同时还存在波潜伏期及波间期延长、振幅降低。随着黄疸程度加重即胆红素水平的升高,ABR波形潜伏期也逐渐延长,达一定水平后影响中枢听觉神经。

Objective To investigate the characteristics of auditory brainstem response （ABR） in term neonates with different serum bilirubin levels. Methods A total of 442 term neonates admitted to neonatal ward with neonatal jaundice [ excluded the neonates with hypoxic ischemic encephalopathy （HIE）, intracranial hemorrhage, intracranial infection and neonates receiving mechanical ventilation ] from July 2010 to April 2011 received ABR examinations. The period of latency （PL）, interval period of latency （IPL） and amplitude （AMP） of I , ]lI and V waves were measured. All neonates were assigned into three groups according to serum bilirubin levels： mild group （40 cases） ： serum bilirubin ≤250 μmol/L, medium group（ 140 cases） ： serum bilirubin between 250 and 300 μmol/L, severe group （262 cases）： serum bihrubin ≥300 μmol/L. The characteristics of ABR in these groups were compared. Results Of all the 442 cases, the abnormal rate of ABR in male neonates was 46.2% and female 29.8%. There was significant difference between the two genders （P 〈0. 01 ）. The male neonates had statistically significant higher thresholds of both ears than the female neonates（ left ear： 39.6 dBnHL vs. 32. 2 dBnHL, right ear： 38.7 dBnHL vs. 34.3 dBnHL, P 〈 0. 01 ）. The abnormal ABR rate of severe group was 40. 8%, significantly higher than the mild group （25.0%） （P 〈 0. 05 ）. There were no significant differences between severe group and the medium group（37.9% ） or medium group and the mild group （ P 〉 0. 05 ）. The wave I PL of three groups had significant difference between groups （P 〈 0. 05）. PL of wave V and IPL of wave I - ~ in the severe group were significantly longer than mild group and medium group （ P 〈 0.01 ）, there was no significant difference between mild group and medium group （P 〉 0. 05 ）. Conclusions In term neonates with jaundice, the incidence of hearing impairment of male was higher than female. Elevated serum bilirubin might increase hearing threshold, elongate PL and IPL, and decrease AMP. As the serum bilirubin level increased, the PL of ABR wave might also extended. When bilirubin reached certain level, the central auditory nerve would be affected.