Constable P D, Streeter R N, Koenig G J, Perkins N R, Gohar H M, Morin D E
Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, USA.
J Vet Intern Med. 1997 Mar-Apr;11(2):71-9. doi: 10.1111/j.1939-1676.1997.tb00076.x.
The objectives of this study were to investigate the determinants of the anion gap (AG) in cattle and to evaluate the utility of AG in detecting hyperlactatemia in sick neonatal calves and adult cattle. The AG was calculated as AG = ([Na+] + [K+])-([Cl-] + [HCO-3]), with all values in mEq/L. The AG of healthy neonatal calves (n = 16) was 29.6 +/- 6.2 mEq/L (mean +/- SD), and the blood L-lactate concentration ranged from 0.5 to 1.2 mM/L. The AG was significantly (P < .05) correlated with serum phosphate (r = .66) and creatinine (r = .51) concentrations. The AG of neonatal calves with experimentally induced diarrhea (n = 16) was 28.6 +/- 5.6 mEq/L, and the blood L-lactate concentration ranged from 1.1 to 2.9 mM/L. The AG was significantly correlated with blood L-lactate concentration (r = .67), serum phosphate concentration (r = .63), creatinine concentration (r = .76), and blood pH (r = -.61). The AG of adult cattle with abomasal volvulus (n = 41) was 20.5 +/- 7.8 mEq/L, and the blood L-lactate concentration ranged from 0.6 to 15.6 mM/L. The AG was significantly correlated with blood L-lactate concentration (r = .60), serum phosphate concentration (r = .71), creatinine concentration (r = .65), albumin concentration (r = .47), total protein concentration (r = .54), blood pyruvate concentration (r = .67), and blood pH (r = -.41) but not plasma beta-OH butyrate concentration. The results indicate that the AG in cattle is only moderately correlated with blood L-lactate concentration and is similarly correlated with serum phosphate and creatinine concentrations in neonatal calves and adult cattle, as well as with serum albumin and total protein concentrations in adult cattle. Anion gap determination is of limited usefulness in predicting blood L-lactate concentration in sick cattle, whereas the correlation between AG and serum creatinine concentration in sick cattle suggests that an increased AG should alert the clinician to the potential presence of uremic anions.
本研究的目的是调查牛阴离子间隙（AG）的决定因素，并评估AG在检测患病新生犊牛和成年牛高乳酸血症中的效用。AG的计算方法为AG =（[Na + ] + [K + ]）-（[Cl - ] + [HCO₃⁻]），所有值的单位均为mEq/L。健康新生犊牛（n = 16）的AG为29.6±6.2 mEq/L（平均值±标准差），血液L-乳酸浓度范围为0.5至1.2 mM/L。AG与血清磷酸盐（r = 0.66）和肌酐（r = 0.51）浓度显著相关（P <0.05）。实验性诱导腹泻的新生犊牛（n = 16）的AG为28.6±5.6 mEq/L，血液L-乳酸浓度范围为1.1至2.9 mM/L。AG与血液L-乳酸浓度（r = 0.67）、血清磷酸盐浓度（r = 0.63）、肌酐浓度（r = 0.76）和血液pH（r = -0.61）显著相关。患有皱胃扭转的成年牛（n = 41）的AG为20.5±7.8 mEq/L，血液L-乳酸浓度范围为0.6至15.6 mM/L。AG与血液L-乳酸浓度（r = 0.60）、血清磷酸盐浓度（r = 0.71）、肌酐浓度（r = 0.65）、白蛋白浓度（r = 0.47）、总蛋白浓度（r = 0.54）、血液丙酮酸浓度（r = 0.67）和血液pH（r = -0.41）显著相关，但与血浆β-羟基丁酸酯浓度无关。结果表明，牛的AG与血液L-乳酸浓度仅呈中度相关，并且与新生犊牛和成年牛的血清磷酸盐和肌酐浓度以及成年牛的血清白蛋白和总蛋白浓度相似。阴离子间隙测定在预测患病牛的血液L-乳酸浓度方面作用有限，而患病牛中AG与血清肌酐浓度之间的相关性表明，AG升高应提醒临床医生注意尿毒症阴离子的潜在存在。
