Buist A S, Vollmer W M, Johnson L R, McCamant L E
Department of Medicine, Oregon Health Sciences University, Portland 97201.
Am Rev Respir Dis. 1988 Feb;137(2):293-301. doi: 10.1164/ajrccm/137.2.293.
We report here the results of a 9- to 11-yr follow-up of 2 cohorts in which spirometry and the single-breath N2 test were used throughout the follow-up period to determine the usefulness of the single-breath N2 test in identifying the smoker who is experiencing a rapid decline in FEV1 and is therefore likely to be at risk of developing chronic airflow limitation. The analyses are based on 734 subjects tested from 3 to 5 times over the follow-up period; 82 smokers developed an abnormal FEV1 during the follow-up period. Of these, 71 (87%) had had an abnormal single-breath N2 test at some time prior to the FEV1 becoming abnormal. Of the single-breath N2 test variables, CC/TLC was the only one significantly associated with the rate of decline of FEV1 in both cohorts once adjustments were made for age, sex, height, and smoking. We conclude that the single-breath N2 test can be useful in identifying the smoker who is at risk of developing chronic airflow limitation. However, its usefulness is diminished by the high proportion of smokers who have mild functional abnormalities but do not progress to develop chronic airflow limitation. We also find that the single-breath N2 test does not appear to have a useful predictive value in nonsmokers.
我们在此报告了对两个队列进行9至11年随访的结果，在整个随访期间使用肺活量测定法和单次呼吸氮气试验，以确定单次呼吸氮气试验在识别第一秒用力呼气容积（FEV1）迅速下降、因此可能有发展为慢性气流受限风险的吸烟者中的作用。分析基于随访期间接受3至5次测试的734名受试者；82名吸烟者在随访期间出现FEV1异常。其中，71名（87%）在FEV1异常之前的某个时间单次呼吸氮气试验结果异常。在单次呼吸氮气试验变量中，经年龄、性别、身高和吸烟情况校正后，在两个队列中，闭合容量/肺总量（CC/TLC）是唯一与FEV1下降速率显著相关的变量。我们得出结论，单次呼吸氮气试验有助于识别有发展为慢性气流受限风险的吸烟者。然而，由于有轻度功能异常但未发展为慢性气流受限的吸烟者比例较高，其作用有所减弱。我们还发现，单次呼吸氮气试验在非吸烟者中似乎没有有用的预测价值。
