Alevrakis Emmanouil, Papadakis Dimitrios-Dorotheos, Vagionas Dimitrios, Koutsoukou Antonia, Pontikis Konstantinos, Rovina Nikoletta, Vasileiadis Ioannis
4th Department of Respiratory Medicine, Athens General Hospital for Thoracic Diseases "Sotiria" Athens, Greece.
Department of Pathophysiology, Medical School, National and Kapodistrian University of Athens Athens, Greece.
Int J Physiol Pathophysiol Pharmacol. 2024 Apr 15;16(2):10-27. doi: 10.62347/PTUU2265. eCollection 2024.
Metabolic acidosis is very common amongst critically ill sepsis patients partly due to the presence of unmeasured ions in serum. These ions can be detected by anion gap (AG) or strong ion gap (SIG) concentration values. The purpose of this study is to assess the correlation and potential agreement of the two methods in critically ill patients with sepsis.
The present is a retrospective study including septic patients admitted to the Intensive Care Unit from December 2014 to July 2016. The [SIG] and the [AG] corrected for albumin and lactate ([AG]) were calculated on admission and on sepsis remission or deterioration. The correlation of the two parameters was assessed in all patient groups using the Pearson correlation coefficient and linear regression analysis and the agreement with Bland-Altman plots. ROC survival curves were also generated for the patients in relation to the values of [AG], [SIG] and inorganic [SIG] ([SIG]) on admission.
There was a strong correlation linking [AG] and [SIG] values (r>0.9, P<0.05) in all patient groups. The results from all three linear regression equations were statistically significant as the models predicted the [AG] value from the [SIG] value with high accuracy. The mean difference of the two methods (i.e. [AG] - [SIG] in every patient separately) in septic patients on admission was 11.75 mEq/l with 95% limits of agreement [9.7-13.8]; in patients with sepsis deterioration, it was 11.8 mEq/l with 95% limits of agreement [9.8-13.7] and in patients with sepsis remission, it was 11.5 mEq/l with 95% limits of agreement [10.4-12.7]. ROC survival curves demonstrated a small area under the curve (AUC): [SIG] AUC: 0.479, 95% CI [0.351, 0.606], [SIG] AUC: 0.581, 95% CI [0.457, 0.705], [AG] AUC: 0.529, 95% CI [0.401, 0.656].
[AG] and [SIG] demonstrate excellent correlation in septic patients, with a mean difference of about 12 mEq/l. Both parameters failed to demonstrate any predictive ability regarding patient mortality.
代谢性酸中毒在重症脓毒症患者中非常常见，部分原因是血清中存在无法测量的离子。这些离子可通过阴离子间隙（AG）或强离子间隙（SIG）浓度值检测。本研究的目的是评估这两种方法在重症脓毒症患者中的相关性和潜在一致性。
本研究为回顾性研究，纳入了2014年12月至2016年7月入住重症监护病房的脓毒症患者。在入院时以及脓毒症缓解或恶化时计算校正白蛋白和乳酸后的[SIG]以及[AG]。使用Pearson相关系数和线性回归分析评估所有患者组中这两个参数的相关性，并通过Bland-Altman图评估一致性。还针对患者入院时的[AG]、[SIG]和无机[SIG]（[SIG]）值生成ROC生存曲线。
所有患者组中[AG]和[SIG]值之间存在强相关性（r>0.9，P<0.05）。所有三个线性回归方程的结果均具有统计学意义，因为模型能够高精度地从[SIG]值预测[AG]值。脓毒症患者入院时两种方法（即分别计算每位患者的[AG]-[SIG]）的平均差值为11.75 mEq/l，一致性界限为95%[9.7 - 13.8]；脓毒症恶化患者中，平均差值为11.8 mEq/l，一致性界限为95%[9.8 - 13.7]；脓毒症缓解患者中，平均差值为11.5 mEq/l，一致性界限为95%[10.4 - 12.7]。ROC生存曲线显示曲线下面积较小：[SIG]曲线下面积（AUC）：0.479，95%置信区间[0.351, 0.606]，[SIG] AUC：0.581，95%置信区间[0.457, 0.705]，[AG] AUC：0.529，95%置信区间[0.401, 0.656]。
[AG]和[SIG]在脓毒症患者中显示出极好的相关性，平均差值约为12 mEq/l。两个参数均未显示出对患者死亡率的任何预测能力。
