Association between anion gap and mortality of aortic aneurysm in intensive care unit after open surgery

Abstract

Background There has not been a well-accepted prognostic model to predict the mortality of aortic aneurysm patients in intensive care unit after open surgery repair. Otherwise, our previous study found that anion gap was a prognosis factor for aortic aneurysm patients. Therefore, we wanted to investigate the relationship between anion gap and mortality of aortic aneurysm patients in intensive care unit after open surgery repair. Methods From Medical Information Mart for Intensive Care III, data of aortic aneurysm patients in intensive care unit after open surgery were enrolled. The primary clinical outcome was defined as death in intensive care unit. Univariate analysis was conducted to compare the baseline data in different groups stratified by clinical outcome or by anion gap level. Restricted cubic spline was drawn to find out the association between anion gap level and mortality. Subgroup analysis was then conducted to show the association in different level and was presented as frost plot. Multivariate regression models were built based on anion gap and were adjusted by admission information, severity score, complication, operation and laboratory indicators. Receiver operating characteristic curves were drawn to compare the prognosis ability of anion gap and simplified acute physiology score II. Decision curve analysis was finally conducted to indicate the net benefit of the models. Results A total of 405 aortic aneurysm patients were enrolled in this study and the in-intensive-care-unit (in-ICU) mortality was 6.9%. Univariate analysis showed that elevated anion gap was associated with high mortality (P value < 0.001), and restricted cubic spline analysis showed the positive correlation between anion gap and mortality. Receiver operating characteristic curve showed that the mortality predictive ability of anion gap approached that of simplified acute physiology score II and even performed better in predicting in-hospital mortality (P value < 0.05). Moreover, models based on anion gap showed that 1 mEq/L increase of anion gap improved up to 42.3% (95% confidence interval 28.5–59.8%) risk of death. Conclusions The level of serum anion gap was an important prognosis factor for aortic aneurysm mortality in intensive care unit after open surgery.

Relationship of Admission Serum Anion Gap and Prognosis of Critically Ill Patients: A Large Multicenter Cohort Study

“…Furthermore, Masevicius et al [ 1 ] conducted a prospective cohort study and discovered that increased unmeasured anions (calculated as AG − lactate) was positively correlated with the risk of mortality in 4901 medical and surgical ICU patients (OR, 1.04; 95% CI, 1.02-1.06). Several recent retrospective studies also demonstrated that elevated AG within the first day of ICU admission was related with increased mortality among critically ill patients with sepsis [ 8 ], congestive heart failure [ 10 ], aortic aneurysm [ 7 ], cardiogenic shock [ 23 ], and acute pancreatitis [ 24 ]. The different study designs and the heterogeneity of study populations may underlie the conflicts in previous reports.…”

“…After reviewing 19 documented studies, a meta-analysis stated that AG was not recommended to evaluate the risk for mortality in critically ill patients [ 6 ]. Whereas, recent studies demonstrated that increased AG was associated with high mortality in ICU patients with aortic aneurysm [ 7 ], sepsis [ 8 ], disseminated intravascular coagulation [ 9 ], and congestive heart failure [ 10 ]. Besides, a study conducted in COVID-19 patients showed that AG was one of the most decisive features for mortality prediction in a machine learning model [ 11 ].…”

Association of Plasma Anion Gap with 28-Day Inhospital Mortality and 1-Year Mortality of Patients with Alcohol Use Disorder at ICU Admission: A Retrospective Cohort Study

“…Zhang et al [ 18 ] studied the association between the AG and mortality in critically ill patients with cardiogenic shock (CS) and suggested that higher AG was related to increased risk of 30-day, 90-day, and 1-year all-cause mortality, HRs (95% CIs) were as follows: 1.62 (1.14–2.30), 1.35 (1.04-1.84), and 1.38 (1.03-1.84), respectively. Gao et al [ 24 ] found that the mortality of aortic aneurysm (AA) in ICU after open surgery increased with increased AG level (OR 1.286, 95% CI: 1.053-1.651) and the growing tendency of mortality was sharper when the AG level was higher than 12 mEq/L. Additionally, Cheng et al [ 16 ] proposed higher AG as a significant predictor of 30-day, 90-day, and 365-day all-cause mortality compared with lower AG (HR, 95% CI: 1.54, 1.33–1.75), 1.55 (1.38-1.73), and 1.46 (1.31-1.60) in critically ill patients with acute kidney injury (AKI).…”

“…Patients were grouped into quintiles by the AG according to cutoffs derived from clinical experience and literatures [ 16 , 18 , 23 , 24 ]. The Kaplan-Meier curves were presented for survival analysis, and log-rank tests were used to compare survival rates between groups.…”

The Anion Gap and Mortality in Critically Ill Patients with Hip Fractures

“…The serum anion gap (AG) arises when there is an excessive synthesis of organic acid anions and/or an equivalent reduction in anion secretion [ 4 , 5 ]. AG is a potential parameter that can be computed mathematically and utilized in diagnosing different metabolic acidosis [ 6 , 7 ]. The numerous studies conducted recently have revealed that anion gap (AG) has a promising predictive value for various ailments, for instance, heart failure [ 8 ], coronary heart disease [ 9 ], and myocardial infarction [ 10 , 11 ].…”