慢肺活量与用力肺活量的差异可预测慢性阻塞性肺疾病患者气道阻塞严重程度

目的通过分析慢肺活量(VC)与用力肺活量(FVC)的差异,探讨两种肺活量指标在评估稳定期慢性阻塞性肺疾病(COPD)患者气流受限程度中的作用。方法纳入200例稳定期COPD患者和114例健康受试者,行肺功能测定VC、FVC、第1秒用力呼气容积(FEV1)、第1秒用力呼气容积占预计值百分比(FEV1%pred)。结果 COPD组VC与FVC的差值(VC-FVC)显著大于对照组[(145.40±157.50)mL比(21.10±61.30)mL,P<0.001],COPD组FVC与VC的比值(FVC/VC)显著低于对照组[(93.61±7.10)%比(99.27±2.24)%,P<0.001]。COPD组VC-FVC与FEV1%pred呈负相关(r=-0.412,P<0.001),FVC/VC与FEV1%pred呈正相关(r=0.517,P<0.001)。FEV1%pred≥50%的COPD患者VC-FVC明显小于FEV1%pred<50%的患者[(78.23±108.26)mL比(189.26±169.21)mL,P=0.003]。结论 VC-FVC和FVC/VC是简便易得的静息肺功能指标,可用作稳定期COPD患者气道阻塞严重程度的辅助诊断。

Difference between Slow and Forced Vital Capacity Can Predict Severity of Chronic Obstructive Pulmonary Disease

Objective To evaluate if the difference between slow vital capacity （VC） and forced vital capacity （FVC） could be used to predict severity of airflow limitation in patients with stable chronic obstructive pulmonary disease （COPD）. Methods VC and FVC were measured in 200 patients with COPD [ 159 males;mean FEV1, （49. 31 ± 15.75 ）% of predicted ] and 114 healthy controls [ 64 males; mean FEVI ,（99. 67 ＋ 13.62）% of predicted]. Results The difference between VC and FVC （VC - FVC）, which showed a negative correlation with FEVl of predicted （ r = - 0. 412, P 〈 0. 001 ）, was significantly larger in the COPD patients than that in the controls [ （ 145.40 _＋ 157. 50） mL vs. （21.10 ＋ 61.30） mL,P 〈 0. 001 ]. The FVC/VC ratio was significantly lower in the COPD patients than that in the controls [ （93.61 ＋ 7. 10）% vs. （99. 27 -＋2. 24）% ,P 〈0. 001 ] ,and was positively correlated with FEV~ of predicted in the COPD patients （r =0. 517 ,P 〈0. 001 ）. There was significant difference in VC- FVC in the COPD patients with FEV1 ~50% of predicted （5 patients in GOLD level 1 and 74 patients in GOLD level 2 ） and those patients with FEV1 〈 50% of predicted （106 patients in GOLD level 3 and 15 patients in GOLD level 4） [ （78.23 -＋ 108. 26 ） mL vs. （ 189.26 -＋ 169. 21 ） mL, P = 0. 003 ]. Conclusion The difference between VC and FVC and the FVC/VC ratio, which are more easily obtained from spirometric test, are able to detect severity of airflow limitation in patients with stable COPD.