Fedde M R, Burger R E, Geiser J, Gratz R K, Estavillo J A, Scheid P
Respir Physiol. 1986 Nov;66(2):109-22. doi: 10.1016/0034-5687(86)90065-4.
Dead space volume (VD) was altered in spontaneously breathing, anesthetized geese from values far above (about 115 ml) to those far below (about 3 ml) the normal VD (approximately 40 ml). Respiratory gases were measured in cranial (CrS) and caudal air sacs (CdS) and in blood. The major findings were as follows: Ventilation increased linearly with VD, by increases in tidal volume (VT) at constant breathing rate (fresp); effective parabronchial ventilation, (VT-VD) X fresp, remained constant and so did arterial blood gases. No changes occurred in CrS gas composition. CdS PCO2 declined with decreasing VD, and the respiratory exchange ratio increased, reaching values above unity at the lowest VD. The gas composition in CrS, and particularly its relation to end-expired gas composition, is in agreement with current models of the gas flow pattern in the avian lung. The PCO2 values in CdS are higher than expected by simple models, e.g. by dead space re-inhalation. Neopulmonic gas exchange and incomplete gas mixing are suggested to contribute significantly to the gas composition of CdS.
在自主呼吸的麻醉鹅中，无效腔容积（VD）发生了变化，从远高于正常VD（约40毫升）的值（约115毫升）降至远低于正常VD的值（约3毫升）。对颅侧气囊（CrS）、尾侧气囊（CdS）和血液中的呼吸气体进行了测量。主要研究结果如下：通气量随VD呈线性增加，通过在恒定呼吸频率（fresp）下增加潮气量（VT）实现；有效的副支气管通气量（VT - VD）×fresp保持恒定，动脉血气也保持恒定。CrS气体成分无变化。CdS的PCO2随VD降低而下降，呼吸交换率增加，在最低VD时达到大于1的值。CrS中的气体成分，特别是其与终末呼气气体成分的关系，与当前关于鸟类肺内气体流动模式的模型一致。CdS中的PCO2值高于简单模型（如无效腔再吸入模型）的预期值。新肺气体交换和不完全气体混合被认为对CdS的气体成分有显著贡献。
