容积二氧化碳图对支气管哮喘患者急性加重分级的意义

目的 探讨容积二氧化碳图(Vcap)参数对支气管哮喘(简称哮喘)诊断的临床价值.方法 2006年7月至2007年5月对64例哮喘急性发作期患者(哮喘组)及20名健康者(健康对照组)进行肺通气功能以及Vcap测定,并依据FEV,占预计值%将哮喘患者分为A组(＞80%,18例)、B组(40%～80%,26例)、c组(＜40%,20例),所有受试者先行Vcap测定,随后完成FEV1占预计值%、FEV1/FVC、FVC占预计值%、最大呼气中段流量(MMEF)占预计值%测定.统计学处理采用SPSS 13.0软件.计量资料采用-x±s表示,计数资料采用卡方检验,计量资料两组间比较采用t检验.肺通气参数与Vcap参数间的相关性采用一元线性回归检验;哮喘组与对照组间的差异采用独立样本t检验;健康对照组及哮喘各亚组间的比较采用单因素方差分析.结果 哮喘组患者FEV1占预计值%、FEV1/FVC、PEF占预计值%、MMEF占预计值%分别为(52±20)%、(50±10)%、(49±16)%、(28±16)%,与健康对照组[(98±9)%、(80±6)%、(91±15)%、(73±7)%]比较差异有统计学意义(t值分别为6.93～13.29,P均＜0.01);哮喘组患者Ⅱ期斜率(dC2/DV)、Ⅲ期斜率(dC3/DV)、Ⅲ期与Ⅱ期斜率之比(SR23)分别为(19±6)%/L、(2.9±1.2)%/L、(16.8±10.6)%,与健康对照组[(31±8)%/L、(1.0±0.4)%/L,(3.3±1.5)%]比较差异有统计学意义(t值分别为5.09、-6.14、-6.54,P均＜0.01);哮喘B、C组dC2/DV分别为(17±5)%/L、(13±4)%/L,与健康对照组[(31±8)%/L]比较差异有统计学意义(t=-11.82、-16.75,P均＜0.01);哮喘B、C组患者dC3/DV、SR23分别为(3.2±0.8)%/L、(17.2±3.5)%,(4.1±1.2)%/L、(28.3±6.9)%,与健康对照组[(1.0±0.4)%/L、(3.3±1.5)%]比较差异有统计学意义(t值分别为2.16～26.08,P均＜0.01);哮喘A、B、C组间dC3/DV、SR23比较差异有统计学意义(t值分别为0.91～22.18,P均＜0.05);相关分析结果表明dC2/DV与FEV1占预计值%、FEV1/FVC、PEF占预计值%、MMEF占预计值%呈正相关(r值分别为0.69、0.54、0.59、0.54,P均＜0.01);dC3/DV与FEV1占预计值%、FEV1/FVC、PEF占预计值%、MMEF占预计值%呈显著负相关(r值分别为-0.62、-0.45、-0.69、-0.58,P均＜0.01);SR23与FEV1占预计值%、FEV1/FVC、PEF占预计值%、MMEF占预计值%呈显著负相关(r值分别为-0.75、-0.52、-0.74、-0.62,P均＜0.01).结论 Vcap是一种简便易行、可定量评估哮喘患者支气管阻塞严重程度的有效方法.

The significance of volumetric capnography in assessment of asthmatic acute exacerbation staging

OBJECTIVE: To investigate the diagnostic value of volumetric capnography in the assessment of asthmatic exacerbation. METHODS: Sixty-four patients with asthma exacerbation and 20 normal controls performed spirometry and volumetric capnography recording. The patients with asthma were divided into three sub-groups according to FEV1% pred (A: > 80%, B:40% - 80%, C: < 40%). RESULTS: FEV1% pred, FEV1/FVC, PEF% pred and MMEF% pred were (98 +/- 9)%, (80 +/- 6)%, (91 +/-15)% and (73 +/- 7)% respectively in the control group, but were (52 +/- 20)%, (50 +/- 10)%, (49 +/-16)% and (28 +/- 16)% respectively in the asthma group, the difference being significant (t = 6.93 - 13.29, all P < 0.01). Compared with the control group, dC2/DV [(19 +/- 6)%/L vs (31 +/- 8)%/L, t = 5. 09, P < 0.01] showed a decrease in the asthma group, dC3/DV [(2.9 +/- 1.2)%/L vs (1.0 +/- 0.4)%/L, t = -6. 14, P < 0.01] and SR23 [(16.8 +/- 10.6)% vs (3.3 +/-1.5)%, t = -6.54, P < 0.01] showed an increase in the asthma group compared to the control group, the difference being significant. Compared with that of the control group, dC2/DV [B:(17 +/-5)%/L, C: (13 +/-4)%/L] showed a decrease (t = -11.82, -16.75, all P < 0.01) and dC3/DV [B:(3.2 +/- 0.8)%/L, C:(4.1 +/-1.2)%/L] and SR23 [B:(17.2 +/- 3.5)%, C:(28.3 +/- 6.9)%] showed an increase (t = 2. 16-26.08, all P < 0.01) in asthma sub-groups B and C. For dC3/DV and SR23, the difference was significant between asthma sub-groups (t = 0.91 -22.18, all P < 0.05). In Pearson correlation analysis, dC2/DV (r = 0.69, 0.54, 0.59, 0.54, all P < 0.01) and dC3/DV (r = -0.62, -0.45, -0.69, -0.58, all P < 0.01) and SR23 (r = -0.75, -0.52, -0.74, -0.62, all P < 0.01) correlated with FEV1% pred, FEV1/FVC, PEF% pred and MMEF% pred. CONCLUSION: Volumetric capnography is a quantitative method for evaluating the severity of airflow obstruction and it can be performed easily during tidal breathing.