阴离子隙和潜在HCO_3~-诊断慢性呼吸衰竭酸碱失衡的临床意义

目的探讨阴离子隙（ＡＧ）和潜在ＨＣＯ－３判断酸碱失衡类型的应用。方法同步测定动脉血气和血电解质，以酸碱失衡预计代偿公式，结合ＡＧ值和潜在ＨＣＯ－３对慢性呼吸衰竭患者进行酸碱失衡类型的判断。结果（１）代谢性酸中毒（代酸）３１例次，其中高ＡＧ代酸２２例次，高Ｃｌ－代酸５例次，如不测定ＡＧ将有１７例次代酸失检；（２）应用ＡＧ后，三重性酸碱失衡（ＴＡＢＤ）从０例增至１４例次，在这１４例ＴＡＢＤ中，如不应用潜在ＨＣＯ－３将有８例失检。结论（１）ＡＧ和潜在ＨＣＯ－３在提高代酸和ＴＡＢＤ诊断率方面发挥了重要的作用，并且提出判断ＴＡＢＤ的标准和步骤；（２）因有诸多因素影响ＡＧ值，使某些代酸患者ＡＧ值不能相应地升高，临床应用时应予注意。

Clinical Significance of Anion Gap and Potential HCO-3 Diagnosing AcidBase Disturbance Caused by Chronic Respiratory Failure

Objective To study the application of anion gap(AG) and potential HCO-3 judging the types of acidbase diturbance.Method The arterial blood gas and blood electrolytes must be determined synchronically.The expect compensatory formula of acidbase disturbance combined with the AG value and the potential HCO-3 evaluated the type of acidbase disturbance caused by chronic respiratory failure. Results (1)In 31 cases of metabolic acidosis(MA),22 cases belong to that with elevated AG type,5 cases belong to that with hyperchloride type.If the AG value wasnt determined,17 cases with MA would not be found.(2)After determining AG value,the number of cases showing triple acidbase disturbance(TABD) increased from 0 to 14.In the 14 cases,8 cases would be lost,if potential HCO-3 wasnt determined. Conclusions (1)The AG value and potential HCO-3 were of key significance in elevating the diagnostic rate of MA and TABD.Furthermore,the diagnostic criteria and steps of TABD were proposed.(2)Because there are many factors affecting the AG value,which fails to elevate correspondingly in some patients with MA,this condition should be attracted attention clinically.