强离子隙在特发性肺纤维化患者中的水平改变及临床意义

The level changes and clinical significance of strong ion gap in patients with idiopathic pulmonary fibrosis

目的探讨强离子隙(strong ion gap,SIG)水平在特发性肺纤维化(Idiopathic pulmonary fibrosis,IPF)患者血清中的改变及其与呼吸功能的相关性。方法 2012年1月至2013年6月我院55例IPF患者,根据是否使用家庭呼吸机氧疗分为康复组(35例)和观察组(20例),两组患者随访定期复查肺功能,在测定血气、电解质等的基础上,应用Stewart-Figge方程式计算SIG。综合比较两组患者各项指标和存活率情况。结果 FCV方面,观察组患者FVC水平表现持续下降趋势,由入选时的(2.89±0.43)L,逐渐下降至随访24月时的(2.35±0.55)L(P<0.05),下降程度明显高于康复组,尤其是第18个月(P<0.05)。DLco方面,观察组表现出持续下降趋势,由入选时的(14.2±3.1)ml/(min×mm Hg),逐渐下降至随访24月时的(9.5±1.6)ml/(min×mm Hg)(P<0.05)。在6分钟步行试验,观察组DLco水平表现出持续下降趋势,由入选时的(369.3±69.2)m,至随访24月时的(243.5±61.98)m(P<0.05),而康复组可见第6个月(375.3±29.1)m和第12个月(383.6±35.1)m的短暂升高趋势,各个时间点数据均优于观察组(P<0.05)。在SIG方面,观察组患者SIG水平波动变化不大,随访后的各个时间点均明显高于康复组(P<0.05)。经Pearson直线回归分析,SIG与第12个月的DLco和第12和18个月的6分钟步行实验呈中等正相关(rDLco(12)=0.369,PDLco(12)<0.05;r6mwt(12)=0.404,P6mwt(12)<0.05;r6mwt(18)=0.338,P6mwt(18)<0.05)。结论 IPF患者血清SIG水平明显升高,且随着肺功能恶化程度的加重而升高,与DLco和6分钟步行试验存在一定的相关性,对IPF患者风险评估及治疗评价均具有指导意义。

Objective To investigate the changes of strong ion gap（ SIG） in patients with idiopathic pulmonary fibrosis（ IPF）. Methods 55 cases of IPF patients were enrolled in our study and classified into two groups：the treatment group（ n = 35） and the observation group（ n = 20）. Another normal 10 cases were taken as the control group. On the basis of determination of blood gas and electrolyte,Stewart-Figge methodology equations were used to calculate SIG. Results The level of FCV showed a decreasing tendency from（ 2. 89 ± 0. 43） L to（ 2. 35 ± 0. 55） L in the observation group,which was more obvious than that in the treatment group（ P〈0.05）. The level of DLco decreased from（ 14. 2 ± 3. 1） ml /（ min × mm Hg） to（ 9. 5 ± 1. 6） ml /（ min × mm Hg） in the observation group,but the tendency was more serious than that in the treatment group（ P〈0.05）. For 6MWD,it decreased from（ 369. 3 ±69. 2） m to（ 243. 5 ± 61. 98） m in the observation group（ P〈0.05）,and it increased to（ 375. 3 ± 29. 1） m at the6 thmonth and（ 383. 6 ± 35. 1） m at the 12 thmonth in the treatment group. The level if SIG showed no obvious changes in the observation group,which was clearly higher at any time points in the observation group than in the treatment group. SIG was positively related with the DLco and six-minute walk test（ rDLco（ 12）= 0. 369,PDLco（ 12） 0. 05;r6mwt（ 12）= 0. 404,P6mwt（ 12） 0. 05; r6mwt（ 18）= 0. 338,P6mwt（ 18）〈 0. 05）. Conclusion The SIG level in IPF patients increases significantly,and as the damage of respiratory function elevates,SIG has guiding significance for monitoring the severity and treatment of IPF.