Cotton E K, Grunstein M M
J Appl Physiol Respir Environ Exerc Physiol. 1980 Apr;48(4):587-95. doi: 10.1152/jappl.1980.48.4.587.
The respiratory responses to acute hypoxia were investigated in 21 newborn infants in Leadville, CO. Time-related changes in pulmonary ventilation (VE) described four distinct phases to the hypoxic response characterized by an abrupt initial decrease (phase I), a transient subsequent increase (phase II) and decrease (phase III), and a further transient decrease upon termination of the hypoxic challenge (phase IV). Based on the degree of respiratory stimulation during phase II, the subjects were divided into two groups, "responders" and "nonresponders." In both groups in VE were attributed to variation in tidal volume (VT), inspiratory duration (TI), and breath duration being little affected. The latter indicated an absence of vagal volume-related modulation of respiratory pattern. In all subjects, a fixed linear function described the relationship between the mean inspiratory flows at 0.3 s after inspiratory onset (i.e., V0.3/0.3) ant at end inspiration (i.e., VT/TI). Thus, changes in respiratory output with hypoxia are attributed to variations in both the "gain" and "shape" of the inspiratory drive.
对科罗拉多州莱德维尔市的21名新生儿的急性低氧呼吸反应进行了研究。肺通气（VE）随时间的变化描述了低氧反应的四个不同阶段，其特征为最初的突然下降（第一阶段）、随后短暂增加（第二阶段）然后下降（第三阶段），以及在低氧刺激终止时进一步短暂下降（第四阶段）。根据第二阶段的呼吸刺激程度，受试者被分为两组，即“反应者”和“无反应者”。两组中的VE变化均归因于潮气量（VT）的变化，吸气持续时间（TI）和呼吸持续时间受影响较小。后者表明不存在与迷走神经容量相关的呼吸模式调节。在所有受试者中，一个固定的线性函数描述了吸气开始后0.3秒（即V0.3/0.3）和吸气末（即VT/TI）时平均吸气流量之间的关系。因此，低氧时呼吸输出的变化归因于吸气驱动的“增益”和“形状”的变化。
