Wrenn K
Division of Emergency Medicine, Strong Memorial Hospital, Rochester, New York 14642.
Ann Emerg Med. 1990 Nov;19(11):1310-3. doi: 10.1016/s0196-0644(05)82292-9.
The anion gap (AG) is a helpful, yet underused, clinical tool. Not only does the presence of a high AG suggest a certain differential, but knowledge of the relationship between the rise in AG (delta AG) and the fall in bicarbonate (delta HCO3) is important in understanding mixed acid-based disorders. Simple arithmetic converts this relationship into a numerical value, the delta gap (delta gap). The delta gap = delta AG - delta HCO3. If the delta gap is significantly positive (greater than +6), a metabolic alkalosis is usually present because the rise in AG is more than the fall in HCO3. Conversely, if the delta gap is significantly negative (less than -6), then a hyperchloremic acidosis is usually present because the rise in AG is less than the fall in HCO3. Familarity with the relationship between the changes in AG and HCO3 can be useful in unmasking occult metabolic disorders.
阴离子间隙（AG）是一种有用但未得到充分利用的临床工具。高AG的存在不仅提示了某种鉴别诊断，而且了解AG升高（ΔAG）与碳酸氢盐降低（ΔHCO3）之间的关系对于理解混合性酸碱紊乱很重要。简单的算术运算将这种关系转化为一个数值，即Δ间隙（Δ间隙）。Δ间隙=ΔAG - ΔHCO3。如果Δ间隙显著为正（大于+6），通常存在代谢性碱中毒，因为AG的升高超过了HCO3的降低。相反，如果Δ间隙显著为负（小于-6），那么通常存在高氯性酸中毒，因为AG的升高小于HCO3的降低。熟悉AG和HCO3变化之间的关系有助于揭示隐匿性代谢紊乱。
