Burgess J L, Brodkin C A, Daniell W E, Pappas G P, Keifer M C, Stover B D, Edland S D, Barnhart S
Arizona Prevention Center, College of Medicine, University of Arizona, Tucson, Arizona, USA.
Am J Respir Crit Care Med. 1999 Jan;159(1):119-24. doi: 10.1164/ajrccm.159.1.9804153.
Seattle firefighters participate in a voluntary annual medical surveillance program including measurements of ventilatory capacity (FVC and FEV1) and single-breath diffusing capacity of carbon monoxide (DLCO). From 1989 to 1996, average % predicted DLCO (Crapo) for all participating firefighters declined from 94.4% (95% confidence interval [CI]: 93.4% to 95.5%) to 87.3% (95% CI: 86.2% to 88.3%), with no significant change in average FVC or FEV1. A random-effects regression model based on data from 812 firefighters with at least two annual sets of DLCO measurements showed the expected associations between DLCO and age, height, gender, race, ventilatory capacity, and smoking. In addition, two important temporal changes were observed, including, for an average firefighter, a large mean decline in DLCO of -1.02 ml/min/mm Hg associated with year of measurement, and a relatively smaller decline of -0.006 ml/min/mm Hg associated with number of fires fought. Although the stability of ventilatory capacity over time is reassuring, the marked temporal decline in diffusing capacity among this population of firefighters raises issues of concern. Interpretation of the observed decline poses a dilemma in terms of the reliability and efficacy of diffusing capacity as a screening tool, in whether DLCO is subject to unacceptable technical variability or whether it might provide more sensitive detection of early adverse respiratory effects of smoke inhalation.
西雅图消防员参与一项年度自愿医学监测项目，该项目包括测量通气能力（用力肺活量[FVC]和第一秒用力呼气容积[FEV1]）以及一氧化碳单次呼吸弥散量（DLCO）。从1989年到1996年，所有参与项目的消防员的预计DLCO（Crapo法）平均百分比从94.4%（95%置信区间[CI]：93.4%至95.5%）降至87.3%（95%CI：86.2%至88.3%），而平均FVC或FEV1无显著变化。基于812名至少有两组年度DLCO测量数据的消防员的数据建立的随机效应回归模型显示了DLCO与年龄、身高、性别、种族、通气能力和吸烟之间的预期关联。此外，还观察到两个重要的时间变化，包括对于一名普通消防员而言，与测量年份相关的DLCO平均大幅下降-1.02 ml/min/mm Hg，以及与灭火次数相关的相对较小的下降-0.006 ml/min/mm Hg。尽管通气能力随时间的稳定性令人放心，但这群消防员中弥散量随时间的显著下降引发了令人担忧的问题。就弥散量作为一种筛查工具的可靠性和有效性而言，对于观察到的下降的解读存在两难困境，即DLCO是否存在不可接受的技术变异性，或者它是否可能更敏感地检测到吸入烟雾对呼吸系统的早期不良影响。
