稳定期慢性阻塞性肺疾病患者深吸气量测定的临床意义

目的探讨深吸气量测定对稳定期慢性阻塞性肺疾病（COPD）患者气流阻塞变化和呼吸困难严重程度的临床意义。方法对61例中度稳定期COPD患者进行常规肺功能检测，以Borg指数判断受试者呼吸困难的严重程度。所有患者在吸入400μg沙丁胺醇后重复检测肺功能和呼吸困难分级，36例在进行6min步行试验（6MWT）后重复肺功能检测和呼吸困难分级。结果吸入沙丁胺醇后，COPD患者的深吸气量和第一秒用力呼气容积（FEV1）分别为（1．6±0．5）和（1．3±0．4）L，均显著高于吸入前的（1．4±0．5）和（1．1±0．4）L，深吸气量平均改善率为（20±16）％，FEV。平均改善率为（11±4）％，差异有统计学意义（t=-3．970，P〈0．01）；其中深吸气量改善率≥10％的占75．4％（46／61），FEV1改善率≥10％的占39．3％（24／61），差异有统计学意义（x^2=16．190，P〈0．01）。治疗后Borg指数（3．0±0．7）显著低于治疗前（3．9±0．8）。6MWT后，COPD患者深吸气量为（1．1±0．4）L，FEV1为（1．0±0．4）L，均显著低于6MWT前的（1．4±0．5）和（1．1±0．4）L，深吸气量平均恶化率为（26±8）％，FEV1平均恶化率为（14±6）％，差异有统计学意义（t=-7．279，P〈0．01），其中深吸气量恶化率≥10％的占100％（36／36），FEV1恶化率≥10％的占72．2％（26／36），差异有统计学意义（x^2=11．613，P〈0．01）。运动后Borg指数（5．6±1．0）显著高于运动前（3．9±0．9）。治疗前后深吸气量差值与治疗前后Borg指数差值、运动前后深吸气量差值与运动前后Borg指数差值均呈显著正相关。静息状态未吸入沙丁胺醇时深吸气量与功能残气量、治疗前后深吸气量差值与治疗前后功能残气量差值、运动前后深吸气量差值与运动前后功能残气量差值均呈显著负相关。结论与FEV1比较，深吸气量检出稳定期COPD患者气流阻塞变化的敏感性比较高，能较准确地反映患者呼吸困难的严重程度。

The clinical significance of inspiratory capacity measurement in patients with stable chronic obstructive pulmonary disease

OBJECTIVE: To study the clinical significance of inspiratory capacity (IC) in the evaluation of airflow obstruction and chronic dyspnea in patients with stable chronic obstruction pulmonary disease (COPD). METHODS: Sixty-one moderate COPD patients underwent pulmonary function test. Borg Scales (BS) was used for the degree of exertional dyspnea. Measurements of pulmonary function and BS were also performed after salbutamol inhalation (400 microg) in 61 COPD patients and after 6-minute walk test (6MWT) in 36 COPD patients. RESULTS: After salbutamol administration, the patients showed a significant increase in IC (1.6+/-0.5) L vs (1.4+/-0.5) L] and in FEV1 (1.3+/-0.4) L vs (1.1+/-0.4) L]. The reversibility in IC was significantly higher than that in FEV1 (20+/-16)% vs (11+/-4)%]. A reversibility greater or equal to 10% in IC was found in 75.4% (46/61) of the patients, but in FEV1 was found in 39.3% (24/61); the difference was significant (chi2=16.190, P<0.01). BS was significantly decreased after salbutamol administration (3.0+/-0.7 vs 3.9+/-0.8, P<0.01). After 6MWT, the 36 COPD patients showed a significant decrease in IC (1.1+/-0.4) L vs (1.4+/-0.5) L] and in FEV1 (1.0+/-0.4) L vs (1.1+/-0.4) L]. The decrease in IC was significantly greater than that in FEV1 (26+/-8)% vs (14+/-6)%]. A decrease greater or equal to 10% in IC was found in 100% (36/36) of the patients and in FEV1 was found in 72.2% (26/36); the difference was significant (chi2=11.613, P<0.01). BS was significantly higher after 6MWT (5.6+/-1.0 vs 3.9+/-0.9, P<0.01). In the multiple regression analysis, the change of IC after and before therapy (DeltaICthe) with the change of BS after and before therapy (DeltaBSthe), and the change of IC after and before exercise (DeltaICexe) with the change of BS after and before exercise (DeltaBSexe), were significantly correlated (regression coefficient was 0.314 and 0.329, respectively, all P<0.05). In Pearson correlation analysis, IC with functional residual capacity (FRC), DeltaICthe with DeltaFRCthe and DeltaIC with DeltaFRC were negatively correlated (r=-0.416 and -0.826 and -0.778, respectively, all P<0.05 or P<0.01). CONCLUSION: IC may be more sensitive than FEV1 in evaluation of change of airflow obstruction and dyspnea in stable COPD patients.