Papastamelos C, Panitch H B, England S E, Allen J L
St. Christopher's Hospital for Children, Department of Pediatrics, Temple University Medical School, Philadelphia, Pennsylvania 19143.
J Appl Physiol (1985). 1995 Jan;78(1):179-84. doi: 10.1152/jappl.1995.78.1.179.
Development of chest wall stiffness between infancy and adulthood has important consequences for respiratory system function. To test the hypothesis that there is substantial stiffening of the chest wall in the first few years of life, we measured passive chest wall compliance (Cw) in 40 sedated humans 2 wk-3.5 yr old. Respiratory muscles were relaxed with manual ventilation applied during the Mead-Whittenberger technique. Respiratory system compliance (Crs) and lung compliance (Cl) were calculated from airway opening pressure, transpulmonary pressure, and tidal volume. Cw was calculated as 1/Cw = 1/Crs - 1/Cl during manual ventilation. Mean Cw per kilogram in infants < 1 yr old was significantly higher than that in children > 1 yr old (2.80 +/- 0.87 vs. 2.04 +/- 0.51 ml.cmH2O-1.kg-1; P = 0.002). There was an inverse linear relationship between age and mean Cw per kilogram (r = -0.495, slope -0.037; P < 0.001). In subjects with normal Cl during spontaneous breathing, Cw/spontaneous Cl was 2.86 +/- 1.06 in infants < 1 yr old and 1.33 +/- 0.36 in older children (P = 0.005). We conclude that in infancy the chest wall is nearly three times as compliant as the lung and that by the 2nd year of life chest wall stiffness increases to the point that the chest wall and lung are nearly equally compliant, as in adulthood. Stiffening of the chest wall may play a major role in developmental changes in respiratory system function such as the ability to passively maintain resting lung volume and improved ventilatory efficiency afforded by reduced rib cage distortion.
从婴儿期到成年期胸壁硬度的发展对呼吸系统功能具有重要影响。为了验证生命最初几年胸壁会显著变硬这一假设，我们测量了40名2周龄至3.5岁处于镇静状态的人类的被动胸壁顺应性（Cw）。在应用米德 - 惠滕伯格技术期间，通过手动通气使呼吸肌放松。根据气道开口压力、跨肺压和潮气量计算呼吸系统顺应性（Crs）和肺顺应性（Cl）。在手动通气期间，Cw计算为1/Cw = 1/Crs - 1/Cl。1岁以下婴儿每千克体重的平均Cw显著高于1岁以上儿童（2.80±0.87 vs. 2.04±0.51 ml·cmH₂O⁻¹·kg⁻¹；P = 0.002）。年龄与每千克体重的平均Cw之间存在负线性关系（r = -0.495，斜率 -0.037；P < 0.001）。在自主呼吸时Cl正常的受试者中，1岁以下婴儿的Cw/自主呼吸时的Cl为2.86±1.06，大龄儿童为1.33±0.36（P = 0.005）。我们得出结论，在婴儿期胸壁的顺应性几乎是肺的三倍，到生命第二年时胸壁硬度增加到胸壁和肺的顺应性几乎相等的程度，如同在成年期一样。胸壁变硬可能在呼吸系统功能的发育变化中起主要作用，例如被动维持静息肺容量的能力以及因胸廓变形减少而提高的通气效率。
