Block A J, Bush C M, White C, Boysen P G, Wynne J W, Taasan V C
Am Rev Respir Dis. 1981 Sep;124(3):330-2. doi: 10.1164/arrd.1981.124.3.330.
We have devised a method to measure functional residual capacity (FRC) in the recumbent, spontaneously breathing patient. Simultaneous anteroposterior and lateral chest radiographs were exposed at the end of an exhalation, as determined by tracings of flow sensed by a nasal thermistor. The volume of the lungs was then planimetrically measured. Functional residual capacity was sequentially measured in 20 supine subjects, both by a helium dilution technique and by the radiographic technique. Planimetric measurement of FRC correlated well with the helium dilution technique, with a range of FRC measurements from 1.53 to 6.41 L (r = 0.94). This method of measuring lung volume should be useful in evaluating changes in FRC associated with different sleep stages and in explaining the mechanisms causing nocturnal oxygen desaturation in patients with chronic obstructive lung disease.
我们设计了一种方法来测量仰卧位自主呼吸患者的功能残气量（FRC）。通过鼻热敏电阻检测的流量描记来确定呼气末，同时拍摄胸部前后位和侧位X线片。然后通过面积测量法测量肺容积。对20名仰卧位受试者依次采用氦稀释技术和X线摄影技术测量功能残气量。功能残气量的面积测量法与氦稀释技术相关性良好，功能残气量测量范围为1.53至6.41升（r = 0.94）。这种测量肺容积的方法在评估与不同睡眠阶段相关的功能残气量变化以及解释慢性阻塞性肺疾病患者夜间氧饱和度下降的机制方面应该是有用的。
