Nishino T, Kochi T
Department of Anesthesia, National Cancer Center Hospital East, Chiba, Japan.
Am J Respir Crit Care Med. 1994 Sep;150(3):742-6. doi: 10.1164/ajrccm.150.3.8087346.
In response to ventilatory loading, a number of compensatory mechanisms can serve to maintain ventilation at or near control levels. To test the hypothesis that respiratory compensation for inspiratory flow-resistive load during nasal breathing may be different from that during oral breathing, we investigated the ventilatory responses to four different magnitudes of inspiratory flow-resistive loads ("control," "light," "moderate," and "severe" loads: 3.5, 15.0, 51.8, 83.3 cm H2O/L/s at a flow rate of 30 L/min, respectively) during nasal breathing and during oral breathing in 11 conscious subjects. With the control, light, and moderate loads, there were no significant differences in tidal volume (VT), respiratory frequency (f), minute ventilation (VI), and end-tidal (partial) carbon dioxide pressure (PETCO2) between nasal and oral breathing. With the severe load, however, VI and f were significantly lower and PETCO2 was significantly higher during nasal breathing than during oral breathing. Occlusion pressure (P0.1) progressively increased during both nasal and oral breathing with increasing magnitudes of loading. However, the value of P0.1 during oral breathing at the severe loading was significantly higher than that during nasal breathing. Our results indicate that ventilatory compensation for the inspiratory flow-resistive load is better during oral breathing than during nasal breathing.
为应对通气负荷，多种代偿机制可用于将通气维持在或接近对照水平。为验证鼻呼吸时对吸气性气流阻力负荷的呼吸代偿可能不同于口呼吸时这一假设，我们研究了11名清醒受试者在鼻呼吸和口呼吸过程中对四种不同程度吸气性气流阻力负荷（“对照”、“轻度”、“中度”和“重度”负荷：在流速为30L/min时分别为3.5、15.0、51.8、83.3cmH₂O/L/s）的通气反应。在对照、轻度和中度负荷下，鼻呼吸和口呼吸之间的潮气量（VT）、呼吸频率（f）、分钟通气量（VI）和呼气末（部分）二氧化碳分压（PETCO₂）均无显著差异。然而，在重度负荷下，鼻呼吸时的VI和f显著低于口呼吸，而PETCO₂显著高于口呼吸。在鼻呼吸和口呼吸过程中，随着负荷程度增加，阻断压（P0.1）均逐渐升高。然而，在重度负荷下，口呼吸时的P0.1值显著高于鼻呼吸时。我们的结果表明，口呼吸时对吸气性气流阻力负荷的通气代偿优于鼻呼吸。
