DEVELOPMENTAL DETERMINANTS OF UPPER AIRWAY COLLAPSIBILITY

儿童打呼噜比成年人少，阻塞性呼吸暂停也较少，这意味着上呼吸道不太容易折叠。因此，我们假设，由于上呼吸道结构和呼吸驱动的改变，上呼吸道对大气压下负荷的代偿性反应随着年龄的增加而减少。我们测量了20名不打呼、不肥胖的儿童和成人睡眠时的上呼吸道上行压力/流量关系。测量是通过将最大吸气气流与通过面罩施加的鼻压水平相关联来进行的。用上行压力/流量曲线的斜率(SPF)来描述上呼吸道功能。结果发现，儿童的SPF值较成人平缓(8+5vs30+18ml/S/cm H2O，P&lt；0.002)，SPF与年龄(r=0.62，P&lt；0.01)和体重指数(r=0.62，P&lt；0.01)相关。测定了6名儿童和2名成人睡眠时100毫秒内的咬合压(P0.1)，并与SPF呈负相关(r=-0.80，N=8；P&lt；0.02)。结论：上呼吸道对大气压负荷的代偿性反应随年龄增长而降低。这与身体质量指数的增加有关，即使是在不打呼、不肥胖的受试者中也是如此。睡眠中的呼吸驱动在调节上呼吸道反应中起着作用。进一步的研究将评估高碳酸血症对上呼吸道反射的发育反应。

Children snore less than adults, and have fewer obstructive apneas, suggesting a less collapsible upper airway. We therefore hypothesized that the compensatory upper airway responses to subatmospheric pressure loading decrease with age, due to changes in upper airway structure and ventilatory drive. We measured upper airway upstream-pressure/flow relationships during sleep in 20 non-snoring, non-obese children and adults. Measurements were made by correlating maximal inspiratory airflow with the level of nasal pressure applied via a mask. The slope of the upstream-pressure/flow curve (SPF) was used to characterize upper airway function. We found that children had a flatter slope than adults (8 + 5 vs 30 + 18 ml/s/cm H2O, P < 0.002), and that SPF correlated with age (r = 0.62, P < 0.01) and body mass index (r = 0.62, P < 0.01). The occlusion pressure in 100 milliseconds (P0.1) during sleep was measured in 6 children and 2 adults; it correlated inversely with SPF (r = -0.80, N = 8; P < 0.02). We conclude that the upper airway compensatory responses to subatmospheric pressure loading decrease with age. This is associated with increased body mass index, even in non-snoring, non-obese subjects. Ventilatory drive during sleep plays a role in modulating upper airway responses. Further studies will evaluate the developmental response of hypercapnia on upper airway reflexes.