阴离子间隙
(重定向自陰離子間隙)
阴离子间隙(anion gap, AG)是指血浆中未测定的阴离子(undetermined anion, UA)和未测定的阳离子的差值(undetermined cation, UC)的差值,即。[1]“阴离子间隙”也可能指代血清阴离子间隙、尿液阴离子间隙。[2]
计算
Na+是血浆中主要的阳离子,又称可测定的阳离子;HCO3-和Cl-是血浆中主要的阴离子,又称可测定的阴离子。未测定的阳离子(UC)主要包括K+,Ca2+,Mg2+等,未测定的阴离子主要包括Pr-(蛋白质陰離子),HPO42-,SO42-。[1]由此可见,阴离子间隙是血浆钠浓度(体内主要阳离子)与氯离子和碳酸氢盐浓度(体内主要阴离子)之和之间的差值。[3]即[4][5]:
基础代谢检查/电解质: | |||
Na+ = 140 | Cl− = 100 | BUN = 20 | / Glu = 150 \ |
K+ = 4 | CO2 = 22 | PCr = 1.0 | |
动脉血气: | |||
HCO3− = 24 | paCO2 = 40 | paO2 = 95 | pH = 7.40 |
肺泡气: | |||
pACO2 = 36 | pAO2 = 105 | A-a g = 10 | |
其它: | |||
Ca = 9.5 | Mg2+ = 2.0 | PO4 = 1 | |
CK = 55 | BE = −0.36 | AG = 16 | |
血清渗透压/肾: | |||
PMO = 300 | PCO = 295 | POG = 5 | BUN:Cr = 20 |
尿液分析: | |||
UNa+ = 80 | UCl− = 100 | UAG = 5 | FENa = 0.95 |
UK+ = 25 | USG = 1.01 | UCr = 60 | UO = 800 |
蛋白质/胃肠道/肝功能测试: | |||
LDH = 100 | TP = 7.6 | AST = 25 | TBIL = 0.7 |
ALP = 71 | Alb = 4.0 | ALT = 40 | BC = 0.5 |
AST/ALT = 0.6 | BU = 0.2 | ||
AF alb = 3.0 | SAAG = 1.0 | SOG = 60 | |
脑脊液: | |||
CSF alb = 30 | CSF glu = 60 | CSF/S alb = 7.5 | CSF/S glu = 0.6 |
临床意义
阴离子间隙实际上反映了血浆(或血清)中固定酸根(如硫酸盐、磷酸盐和乳酸盐等)的含量,而实验检查通常并不直接测定这些固定酸根的含量。[6]由于阴离子间隙很容易从常规实验室检查结构中计算得到,因此经常被用作代谢性酸中毒,特别是高乳酸血症的筛查。[7]
血浆阴离子间隙的正常值约为10-14mmol/L[1],升高的阴离子间隙可用于判断代谢性酸中毒是由于内源性或外源性酸的增加所致(是否为AG增高型代谢性酸中毒),如当硫酸盐、磷酸盐、乳酸盐或水杨酸根产生增多或排出减少时,阴离子间隙增大。[6][1]阴离子间隙降低的情况可见于低白蛋白血症等UC增加或UA减少的情况。[1]
历史
Emmet和Narins最早于1977年使用阴离子间隙来解释和诊断代谢性酸中毒的病因。[8][9]
参考文献
- ^ 1.0 1.1 1.2 1.3 1.4 肖献忠. 病理生理学 4th. 高等教育出版社. 2018-11-30: 49. ISBN 978-7-04-050887-1.
- ^ Pandey, Devansh G.; Sharma, Sandeep. Biochemistry, Anion Gap. StatPearls. Treasure Island (FL): StatPearls Publishing. 2024 [2024-11-30]. PMID 30969579. (原始内容存档于2024-12-01).
There are three types: serum, plasma, and urine anion gaps.
- ^ Wiener, Sage W. Toxicologic Acid-Base Disorders. Emergency Medicine Clinics of North America. 2014-02, 32 (1): 149–165. doi:10.1016/j.emc.2013.09.011.
- ^ Carroll, Robert G. Integration. Elsevier's Integrated Physiology. 2007: 209–214. doi:10.1016/B978-0-323-04318-2.50023-6.
- ^ Gillham, Michael; Sidebotham, David. Acid-Base Disturbances. Cardiothoracic Critical Care. Elsevier. 2007: 461–469 [2024-12-05]. ISBN 978-0-7506-7572-7. doi:10.1016/b978-075067572-7.50034-5. (原始内容存档于2014-01-28) (英语).
- ^ 6.0 6.1 Sue E. Huether MS, Kathryn L. McCance MS. Understanding Pathophysiology 7th. : 332. ISBN 978-0323639088.
- ^ Dinh, C H; Ng, R; Grandinetti, A; Joffe, A; Chow, D C. Correcting the anion gap for hypoalbuminaemia does not improve detection of hyperlactataemia. Emergency Medicine Journal. 2006-08-01, 23 (8). ISSN 1472-0205. PMC 2564167 . PMID 16858097. doi:10.1136/emj.2005.031898 (英语).
- ^ Emmett, Michael; Narins, Robert G. CLINICAL USE OF THE ANION GAP:. Medicine. 1977-01, 56 (1). ISSN 0025-7974. doi:10.1097/00005792-197756010-00002 (英语).
- ^ Chawla, Lakhmir S; Shih, Shirley; Davison, Danielle; Junker, Christopher; Seneff, Michael G. Anion gap, anion gap corrected for albumin, base deficit and unmeasured anions in critically ill patients: implications on the assessment of metabolic acidosis and the diagnosis of hyperlactatemia. BMC Emergency Medicine. 2008-12, 8 (1) [2024-12-05]. ISSN 1471-227X. PMC 2644323 . PMID 19087326. doi:10.1186/1471-227X-8-18. (原始内容存档于2024-11-30) (英语).