Kiss D, Popp W, Wagner C, Havelec L, Sertl K
Institut für Medizinische Statistik, Vienna, Austria.
Thorax. 1995 Aug;50(8):902-5. doi: 10.1136/thx.50.8.902.
Measurement of the carbon monoxide transfer factor (TLCO) has traditionally been performed using the single breath method but recently the intrabreath method has been developed. The aim of this study was to compare the two methods in the clinical evaluation of patients with obstructive and non-obstructive pulmonary disorders.
Measurements of TLCO with the intrabreath method were carried out on a study sample composed of 50 patients with non-obstructive disorders and 50 with airways obstruction (FEV1/FVC < 70%) either before or after a single breath measurement of the TLCO had been performed. The method involves the continuous analysis of a single slow expirate using a computerised rapid multigas infrared analyser. TLCO, alveolar volume (VA), TLCO/VA, and inspired vital capacity (IVC) values were obtained for both groups by both methods.
When measured with the intrabreath method the group with airways obstruction showed lower TLCO and TLCO/VA values than the non-obstructive group. VA was higher in both patient groups when measured with the intrabreath technique. The same test also showed higher TLCO values with the intrabreath method in the group with non-obstructive disorders and lower TLCO/VA values with the intrabreath method in those with airways obstruction. The corresponding parameters obtained by the two methods correlated closely, with no correlation between the magnitude of the differences with the magnitude of the readings. An index of gas mixing indicated a better distribution of the inspired air for the intrabreath method than for the single breath method. The VA values obtained with the intrabreath method showed a closer agreement to the actual total lung capacities measured by body plethysmography.
The intrabreath method of determining TLCO is comparable to the traditional single breath method. Measurement of alveolar volume by the intrabreath method approximates more closely to total lung capacity, even in subjects with airways obstruction.
一氧化碳转运因子（TLCO）的测量传统上采用单次呼吸法，但最近已开发出呼气中测量法。本研究的目的是在阻塞性和非阻塞性肺部疾病患者的临床评估中比较这两种方法。
在对50例非阻塞性疾病患者和50例气道阻塞（FEV1/FVC<70%）患者组成的研究样本进行TLCO单次呼吸测量之前或之后，采用呼气中测量法测量TLCO。该方法使用计算机化快速多气体红外分析仪对单次缓慢呼气进行连续分析。通过两种方法获得两组的TLCO、肺泡容积（VA）、TLCO/VA和吸气肺活量（IVC）值。
采用呼气中测量法时，气道阻塞组的TLCO和TLCO/VA值低于非阻塞组。采用呼气中测量技术时，两组患者的VA均较高。同一测试还显示，非阻塞性疾病组采用呼气中测量法时TLCO值较高，气道阻塞组采用呼气中测量法时TLCO/VA值较低。两种方法获得的相应参数密切相关，差异大小与读数大小之间无相关性。气体混合指数表明，呼气中测量法的吸入空气分布比单次呼吸法更好。呼气中测量法获得的VA值与通过体容积描记法测量的实际总肺容量更接近。
测定TLCO的呼气中测量法与传统的单次呼吸法相当。即使在气道阻塞的受试者中，呼气中测量法测量的肺泡容积也更接近总肺容量。
