Oster J R, Perez G O, Materson B J
Medical Service, Veterans Administration Medical Center, Miami, FL 33125.
South Med J. 1988 Feb;81(2):229-37. doi: 10.1097/00007611-198802000-00022.
The anion gap (AG) in the serum equals the concentrations of Na-(Cl + HCO3). It is becoming increasingly useful in the interpretation of acid-base disorders and in the diagnosis of other conditions. In an acidemic patient, an elevated AG usually indicates the presence of an organic acidosis, rhabdomyolysis, nonketotic hyperglycemic coma, uremia, or certain intoxications. An increased AG with alkalemia suggests severe alkalosis with hemoconcentration or use of anionic antibiotics (eg, carbenicillin) or salts of organic acids (eg, citrate). An elevated AG with a normal serum pH could be an artifact caused by prolonged exposure of the serum sample to air before processing. A decreased AG with a normal serum pH may indicate hypoalbuminemia, cationic paraproteinemia, halide poisoning, or lithium intoxication. The delta AG/delta HCO3 ratio and the urinary AG may also be quite useful in analyzing complex acid-base disorders.
血清中的阴离子间隙（AG）等于Na⁺浓度减去（Cl⁻浓度 + HCO₃⁻浓度）。它在酸碱平衡紊乱的解读及其他病症的诊断中越来越有用。在酸血症患者中，AG升高通常提示存在有机酸血症、横纹肌溶解、非酮症高血糖昏迷、尿毒症或某些中毒情况。AG升高同时伴有碱血症提示严重碱血症伴血液浓缩或使用了阴离子抗生素（如羧苄西林）或有机酸盐（如柠檬酸盐）。血清pH值正常但AG升高可能是血清样本在处理前长时间暴露于空气中所致的假象。血清pH值正常但AG降低可能提示低白蛋白血症、阳离子副蛋白血症、卤化物中毒或锂中毒。ΔAG/ΔHCO₃比值和尿AG在分析复杂的酸碱平衡紊乱时也可能非常有用。
