Anion gap(AG) or serum lactate-in search of a better prognostic marker in sepsis  a cross-sectional study in a rural tertiary care hospital

Background:   In intensive care units, sepsis is a common diagnosis.  Serum lactate rise has been established as an essential measure for predicting the outcome of sepsis. Higher anion gap(AG) has been associated with an increased risk of death in critically ill individuals. We measured blood lactate levels and AG and looked at how these predicted in-hospital outcomes (death or discharge).This study aimed to estimate anion gap values in sepsis syndrome, to measure the serum lactate levels in sepsis syndrome, to correlate the anion gap and serum lactate values with the outcome (mortality and discharge) in patients with sepsis syndrome. Methods: : The Department of Medicine at Jawaharlal Nehru Medical College conducted this single-center, prospective, observational cross-sectional study with a cohort design. A total of 160 patients with sepsis were screened in the ICU. Sepsis was diagnosed using SEPSIS-3 criteria. Results: :  In this study, we included 160 patients with sepsis with sequential organ failure assessment (SOFA) score >2.Mean serum lactate was 5.1±1.2 mmol/L and it was ≥4 mmol/L in 90% of patients. Mean AG was 14.0±3.9 and it was ≥12 in 75.6% of patients. Similarly, the proportion of patients who had lactate levels ≥4 mmol/L was higher in those with AG ≥12 than AG <12 (95.9% vs. 71.8%, p<0.0001). The AUC of ROC in predicting mortality was significant for both serum lactate (AUC 0.797, p<0.0001) and AG (AUC 0.835, p<0.0001). Conclusions: : Along with other parameters predicting mortality, serum lactate and AG also act as important predictors of mortality in sepsis patients. We conclude that on admission serum lactate ≥4 mmol/L and AG ≥12 can be used in predicting short-term mortality in patients with sepsis.