Irregularities and power law distributions in the breathing pattern in preterm and term infants
Irregularities and power law distributions in the breathing pattern in preterm and term infants
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DOI：
10.1152/jappl.1998.85.3.789
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发表时间：
1998-09-01
影响因子：
3.3
通讯作者：
Suki, B
中科院分区：
文献类型：
--
作者：
Frey, U;Silverman, M;Suki, B
与年龄较大的儿童不同，幼儿容易出现不稳定的呼吸模式，这表明他们在控制呼吸方面存在重大差异。我们通过测量25名早产儿在怀孕后40.5+/-5.2(SD)周的2小时睡眠中的腹部运动来测量呼吸间隔时间(“呼吸间隔”；IBI)来检查婴儿的不规则呼吸模式。14例足月健康婴儿，出生后年龄8.2+/-4wk。我们对10名婴儿进行了两次纵向测量。我们开发了一种检测呼吸的阈值算法，使IBI包括呼吸暂停和潜在的潮气呼吸不足的一些时期(低呼吸)。IBIS的概率密度分布(P)遵循幂定律，P(IBI)类似于IBI-α，指数α提供了呼吸不足的相对风险的统计测量。随着胎龄的成熟，α从41.2+/-3.6wk时的2.62+/-0.4wk增加到47.3wk+/-6.4wk时的3.22+/-0.4wk，表明长时间低呼吸减少(配对数据P=0.002)。IBI的统计特性在呼吸振荡器的模型中得到了很好的再现，该模型基于两个假设：1)呼吸振荡器的紧张性神经输入是有噪声的；2)噪声探索了IBI随着紧张性输入的减少而发散的关键区域。因此，婴儿呼吸控制的成熟可以通过紧张性输入离开这一关键区域来解释。我们得出结论，婴儿的呼吸异常可以用阿尔法来表征，这提供了临床可获得的数据和呼吸振荡器的神经生理学之间的联系。
Unlike older children, young infants are prone to develop unstable respiratory patterns, suggesting important differences in their control of breathing. We examined the irregular breathing pattern in infants by measuring the time interval between breaths ("interbreath interval"; IBI) assessed from abdominal movement during 2 h of sleep in 25 preterm infants at a postconceptional age of 40.5 +/- 5.2 (SD) wk. and in 14 term healthy infants at a postnatal age of 8.2 +/- 4 wk. In 10 infants we performed longitudinal measurements on two occasions. We developed a threshold algorithm for the detection of a breath so that an IBI included an apneic period and potentially some periods of insufficient tidal breathing excursions (hypopneas). The probability density distribution (P) of IBIs follows a power law, P(IBI)similar to IBI-alpha, with the exponent alpha providing a statistical measurement of the relative risk of insufficient breathing. With maturation, alpha increased from 2.62 +/- 0.4 at 41.2 +/- 3.6 wk to 3.22 +/- 0.4 at 47.3 +/- 6.4 wk postconceptional age, indicating a decrease in long hypopneas (for paired data P = 0.002). The statistical properties of IBI were well reproduced in a model of the respiratory oscillator on the basis of two hypotheses: 1) tonic neural inputs to the respiratory oscillator are noisy; and 2) the noise explores a critical region where IBI diverges with decreasing tonic inputs. Accordingly, maturation of infant respiratory control can be explained by the tonic inputs moving away from this critical region. We conclude that breathing irregularities in infants can be characterized by alpha, which provides a link between clinically accessible data and the neurophysiology of the respiratory oscillator.