Inspiratory timing of heart-lung transplant recipients during progressive hypercapnia.
Inspiratory timing of heart-lung transplant recipients during progressive hypercapnia.
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进行性高碳酸血症期间心肺移植受者的吸气时间。
DOI：
10.1152/jappl.1991.71.3.945
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Theodore,J
中科院分区：
文献类型：
--
作者：
Kagawa,FT;Duncan,SR;Theodore,J
在人类进行性高血氧症中，潮气量（VT）和吸气持续时间（TI）之间的关系表现出双相特征：在初始阶段，VT增加而TI保持不变（区I），在随后的阶段，随着VT继续增加，TI相互减少（区II）。II区行为通常归因于肺体积介导的通货膨胀抑制（布鲁尔-赫林反射）。为了研究这一现象，我们比较了10名肺功能测试正常的心肺移植受者（HL）和13名正常对照者的CO2反应。尽管肺去神经支配，HL表现出与对照组相同的II区行为。另外4例合并肺受限的HL患者II区斜率相对降低（P < 0.05），但区域间发生相位变化的绝对VT与其他组无明显差异。我们得出结论，进行性高碳酸血症时，TI缩短发生在没有肺反射的情况下。尽管肺去神经支配，但与相变化相关的室速的一致性表明，这种行为的刺激是肺外呼吸结构的体积位移。
The relationship between tidal volume (VT) and inspiratory duration (TI) displays biphasic characteristics during progressive hypercapnia in humans: an initial phase in which VT increases while TI remains constant (region I) and a subsequent phase with reciprocal decreases of TI as VT continues to increase (region II). Region II behavior is generally attributed, albeit inferentially, to lung volume-mediated inflation inhibition (Breuer-Hering reflex). To investigate this phenomenon, we compared CO2 responses of 10 heart-lung transplant recipients (HL) with normal pulmonary function tests and 13 normal controls. Despite pulmonary denervation, the HL exhibited region II behavior identical to controls. In four additional HL with pulmonary restriction, there were comparative decreases of the region II slope (P less than 0.05), but the absolute VT where the phase change between regions occurred was indistinguishable from the other groups. We conclude that TI shortening in humans during progressive hypercapnia occurs in the absence of pulmonary reflexes. The consistency of the VT associated with phase changes, despite pulmonary denervation, suggests that the stimulus for this behavior is volume displacement of extra-pulmonary respiratory structures.