Tuladhar Rita, Harding Richard, Cranage Susan M, Adamson T Michael, Horne Rosemary S C
Department of Paediatrics, Monash Medical Centre, Monash University, 246 Clayton Road, Melbourne, Victoria 3168, Australia.
Early Hum Dev. 2003 Apr;71(2):157-69. doi: 10.1016/s0378-3782(03)00005-7.
Previous studies have suggested that autonomic dysfunction may be involved in Sudden Infant Death Syndrome (SIDS). The major risk factors for SIDS are the prone sleeping position and maternal smoking. Our aim was to examine the effects of sleeping position and maternal smoking on the postnatal maturation of autonomic function by examining heart rate responses following arousal in healthy term infants. Twenty-four infants (11 born to mothers who smoked during pregnancy and 13 to mother who did not smoke) were studied using daytime polysomnography and multiple measurements of arousal threshold (cm H(2)O) in response to air-jet stimulation applied alternately to the nares were made in both active sleep (AS) and quiet sleep (QS). We demonstrated no difference between smoking and non-smoking groups of infants in any of our measurements, and thus combined data from the groups. Baseline (BHR) was elevated in the prone compared to the supine position in quiet sleep (QS) at 2-3 weeks (p<0.001) and 5-6 months (p<0.001), and in active sleep (AS) at 2-3 and 5-6 months (p<0.05). BHR was significantly elevated in AS compared to QS in the supine position at all ages (p<0.01) and in the prone position at 2-3 (p<0.001) and 5-6 months (p<0.05). Increases in heart rate (deltaHR%) following arousal were significantly greater in the supine compared to the prone position in QS at 2-3 weeks (p<0.05) and in AS at both 2-3 (p<0.01) and 5-6 months (p<0.05). DeltaHR% was significantly greater in AS compared to QS in both supine (p<0.05) and prone (p<0.001) positions at 2-3 weeks and in the supine position at 2-3 months (p<0.001). We conclude that sleep state, sleep position and postnatal age affect the cardiac responses following arousal from sleep in healthy term infants. Impairment of heart rate control in the prone position may be important in understanding the increased risk for SIDS in this position.
以往研究表明，自主神经功能障碍可能与婴儿猝死综合征（SIDS）有关。SIDS的主要危险因素是俯卧睡眠姿势和母亲吸烟。我们的目的是通过检测健康足月儿觉醒后的心率反应，来研究睡眠姿势和母亲吸烟对自主神经功能产后成熟的影响。对24名婴儿（11名母亲孕期吸烟，13名母亲孕期不吸烟）进行了日间多导睡眠图检查，并在主动睡眠（AS）和安静睡眠（QS）状态下，通过交替向鼻孔施加喷气刺激，多次测量觉醒阈值（厘米水柱）。我们发现，在任何测量指标中，吸烟组和非吸烟组婴儿之间均无差异，因此将两组数据合并。在安静睡眠（QS）状态下，2 - 3周（p<0.001）和5 - 6个月（p<0.001）时，俯卧位的基线心率（BHR）高于仰卧位；在主动睡眠（AS）状态下，2 - 3个月和5 - 6个月时（p<0.05），俯卧位的基线心率也高于仰卧位。在所有年龄段，仰卧位时主动睡眠（AS）的BHR显著高于安静睡眠（QS）（p<0.01）；在俯卧位时，2 - 3个月（p<0.001）和5 - 6个月时（p<0.05），主动睡眠（AS）的BHR也显著高于安静睡眠（QS）。在安静睡眠（QS）状态下，2 - 3周时（p<0.05），以及在主动睡眠（AS）状态下，2 - 3个月（p<0.01）和5 - 6个月时（p<0.05），觉醒后心率增加幅度（deltaHR%）仰卧位显著大于俯卧位。在2 - 3周时，仰卧位和俯卧位的主动睡眠（AS）的deltaHR%均显著大于安静睡眠（QS）（p<0.05）；在2 - 3个月时，仰卧位的主动睡眠（AS）的deltaHR%也显著大于安静睡眠（QS）（p<0.001）。我们得出结论，睡眠状态、睡眠姿势和出生后年龄会影响健康足月儿睡眠觉醒后的心脏反应。俯卧位时心率控制受损可能对理解该姿势下SIDS风险增加具有重要意义。
