Predictive value of albumin-corrected anion gap in the prognosis of patients with septic shock
Objective To explore the predictive value of albumin-corrected anion gap(ACAG)in the prognosis of patients with septic shock(SS).Methods The clinical data of 2 511 adult patients with SS in the United States Medical Information Mart for Intensive Care-Ⅳ(MIMIC-Ⅳ,version 2.0;2008-2019)Database were retrospectively analyzed.According to the 90-day prognosis,patients were divided into survival group and death group.According to the ACAG value,patients were divided into low ACAG group(12-20 mmol/L)and high ACAG group(>20 mmol/L).Kaplan-Meier survival curves were drawn,and the log-rank test was used to compare the 30-day and 90-day cumulative survival rates of patients in the low and high ACAG groups.The relationship between ACAG and 90 d all-cause mortality was analyzed by restricted cubic spline(RCS).Multivariate Cox regression model was used to analyze the relationship between ACAG level and 30-day and 90-day all-cause mortality in SS patients.Results A total of 2 511 SS patients were finally included,and the 90-day all-cause mortality rate was 45.56%.There were significant differences between the survival group and the death group in age,Sequential Organ Failure Assessment Score,simplified Acute Physiology Score Ⅱ,lactate,anion gap,albumin,ACAG,red blood cells,platelets,total bilirubin,urea nitrogen,creatinine,total blood calcium,blood phosphorus,ratio of norepinephrine usage,ratio of plasma usage,ratio of mechanical ventilation,ratio of continuous renal replacement therapy,combined malignant tumors,cardiac arrest,acute kidney injury,and ratio of chronic kidney disease(all P<0.05).The 30-day and 90-day all-cause mortality rates of the low ACAG group were 29.73%and 37.74%,respectively,which were both significantly lower than those of the high ACAG group as 42.10%and 51.05%,respectively(both P<0.01).The Kaplan-Meier survival curve showed that compared with the high ACAG group,the 30-day and 90-day cumulative survival rates of the low ACAG group were higher,and the differences were statistically significant(both P<0.01).RCS analysis showed an non-linear trend relationship between ACAG and 90-day all-cause mortality risk(P=0.004).Multivariate Cox regression analysis showed that increased ACAG level(>20 mmol/L)while admitted to ICU was an independent risk factor for 30-day and 90-day all-cause mortality of patients with SS[HR=1.169(95%CI:1.001-1.365)and HR=1.181(95%CI:1.029-1.357)].Conclusion High ACAG levels(>20 mmol/L)at ICU admission have certain predictive value for poor prognosis in SS patients,which is helpful for clinicians to evaluate the prognosis of SS patients and timely and accurately treat patients to improve the survival rate.