te Nijenhuis F C, Jansen J R, Versprille A
Department of Pulmonary Diseases, Erasmus University, Rotterdam, The Netherlands.
Clin Physiol. 1996 Nov;16(6):621-32. doi: 10.1111/j.1475-097x.1996.tb00739.x.
We studied the effect of forced inflation at different alveolar volumes (VA) on carbon monoxide diffusing capacity (DLCO) in anaesthetized, paralysed and mechanically ventilated healthy pigs. An inspiratory pause procedure (equivalent of the single-breath technique) consisting of a pause between an inflation and expiration, both at a constant flow rate, was used. The procedure was computer-controlled and could easily be standardized. In five pigs, VA was varied at constant inflation volume by increasing positive end-expiratory pressure (PEEP) from 2 to 10 cmH2O. Inspiratory pause time was varied from 1 to 8 s to verify whether the decay of CO was exponential. In nine pigs, DLCO was estimated at four different VA values by inflating with 15-30 ml kg-1 at 2 cmH2O PEEP. An exponential decay of CO was always obtained. With increasing VA by either an increase in PEEP or inflation volume, DLCO remained constant. Since the diffusing capacity of the pulmonary membrane is expected to increase with increasing VA, the constant DLCO may be attributed to a decrease in capillary blood volume.
我们研究了在麻醉、麻痹并机械通气的健康猪中，不同肺泡容积（VA）下强制充气对一氧化碳弥散能力（DLCO）的影响。采用了一种吸气暂停程序（等同于单次呼吸技术），即在恒定流速下，在充气和呼气之间设置一个暂停。该程序由计算机控制，且易于标准化。在5头猪中，通过将呼气末正压（PEEP）从2 cmH₂O增加到10 cmH₂O，在恒定充气量下改变VA。吸气暂停时间从1秒变化到8秒，以验证一氧化碳的衰减是否呈指数形式。在9头猪中，在2 cmH₂O PEEP下以15 - 30 ml·kg⁻¹充气，在四个不同的VA值下估计DLCO。一氧化碳总是呈指数衰减。随着通过增加PEEP或充气量来增加VA，DLCO保持恒定。由于预计肺膜的弥散能力会随着VA增加而增强，DLCO保持恒定可能归因于毛细血管血容量的减少。
