Hedenstierna G
Br J Anaesth. 1975 Sep;47(9):993-9. doi: 10.1093/bja/47.9.993.
In 10 patients receiving prolonged respirator treatment, respiratory deadspace was measured at 12, 18 and 24 b.p.m. and with two different minute volumes. The physiological deadspace (the sum of apparatus, anatomical and alveolar deadspaces) was derived using the Bohr equation, and the anatomical and alveolar deadspaces were measured by carbon dioxide analysis. Tracheal pressure was measured concurrently. The physiological deadspace to tidal volume ratio was increased on increasing the frequency, and was slightly reduced by an increase in minute volume. The mean values for anatomical deadspace ranged from 144 to 277 ml under the different conditions studied. Neither frequency nor minute volume had any influence on the VD/VT ratio. The volume of the alveolar deadspace was the less than half of the anatomical deadspace. The VD/VT ratio did not vary with frequency or minute volume. A relationship between tracheal end inspiratory pressure and anatomical deadspace was found, with a correlation coefficient of 0.80. The slope of the regression line indicated a high airway compliance of approximately 10 ml/cm H2O.
在10例接受长期呼吸机治疗的患者中，于每分钟呼吸频率12次、18次和24次以及两种不同的每分通气量下测量呼吸无效腔。采用玻尔方程推导生理无效腔（设备无效腔、解剖无效腔和肺泡无效腔之和），并通过二氧化碳分析测量解剖无效腔和肺泡无效腔。同时测量气管压力。随着频率增加，生理无效腔与潮气量之比升高，而每分通气量增加则使其略有降低。在所研究的不同条件下，解剖无效腔的平均值在144至277毫升之间。频率和每分通气量对无效腔与潮气量之比均无影响。肺泡无效腔的容积小于解剖无效腔的一半。无效腔与潮气量之比不随频率或每分通气量而变化。发现气管吸气末压力与解剖无效腔之间存在关系，相关系数为0.80。回归线的斜率表明气道顺应性较高，约为10毫升/厘米水柱。
