Mecher C, Rackow E C, Astiz M E, Weil M H
Department of Medicine, University of Health Sciences/Chicago Medical School, IL.
Crit Care Med. 1991 May;19(5):705-11. doi: 10.1097/00003246-199105000-00018.
To quantitate the contribution of lactate, phosphate, urate, total serum proteins, and unidentified anions to the anion gap in patients with severe sepsis.
Thirty critically ill patients with evidence of severe sepsis and systemic hypoperfusion were prospectively studied.
The anion gap was calculated as [Na+] + [K+] - [Cl-] - [HCO3]. A corrected anion gap was calculated as the anion gap minus the anionic contribution of lactate, phosphate, urate, and total serum proteins. The corrected anion gap is a marker of unmeasured anion less unmeasured cation concentration.
The mean anion gap was 21.8 +/- 1.4 mmol/L and the corrected anion gap was 3.7 +/- 0.8 mmol/L. The mean arterial blood lactate concentration was 5.9 +/- 0.8 mmol/L. The magnitude of the lactate concentration correlated linearly with the anion gap (r2 = .61, lactate = 0.4 anion gap - 3.9, n = 30, p less than .01). The corrected anion gap was greater than 0 in 24 (80%) of 30 patients. The magnitude of the corrected anion gap correlated linearly with the anion gap (r2 = .66, corrected anion gap = 0.5 anion gap - 6.3, n = 30, p less than .01). Since the slope of the regression line for estimating corrected anion gap from anion gap was 0.5, the contribution of unmeasured anions was as important as lactate in determining the anion gap.
These data indicate that lactic acidosis does not entirely account for the metabolic acidosis during severe sepsis. Furthermore, the increased corrected anion gap suggests the presence of an unidentified anion (or anions) that is (or are) responsible, in large part, for the development of metabolic acidosis in patients with sepsis.
定量分析乳酸、磷酸盐、尿酸盐、总血清蛋白及未识别阴离子对严重脓毒症患者阴离子间隙的贡献。
对30例有严重脓毒症和全身低灌注证据的危重症患者进行前瞻性研究。
阴离子间隙计算为[Na⁺]+[K⁺]-[Cl⁻]-[HCO₃⁻]。校正后的阴离子间隙计算为阴离子间隙减去乳酸、磷酸盐、尿酸盐和总血清蛋白的阴离子贡献。校正后的阴离子间隙是未测阴离子浓度减去未测阳离子浓度的指标。
平均阴离子间隙为21.8±1.4 mmol/L，校正后的阴离子间隙为3.7±0.8 mmol/L。平均动脉血乳酸浓度为5.9±0.8 mmol/L。乳酸浓度的大小与阴离子间隙呈线性相关（r² = 0.61，乳酸 = 0.4×阴离子间隙 - 3.9，n = 30，p < 0.01）。30例患者中有24例（80%）校正后的阴离子间隙大于0。校正后的阴离子间隙大小与阴离子间隙呈线性相关（r² = 0.66，校正后的阴离子间隙 = 0.5×阴离子间隙 - 6.3，n = 30，p < 0.01）。由于根据阴离子间隙估算校正后阴离子间隙的回归线斜率为0.5，因此在确定阴离子间隙时，未测阴离子的贡献与乳酸同样重要。
这些数据表明，乳酸酸中毒并不能完全解释严重脓毒症期间的代谢性酸中毒。此外，校正后阴离子间隙增加提示存在一种（或多种）未识别的阴离子，其在很大程度上导致了脓毒症患者代谢性酸中毒的发生。
