To assess the value of blood ammonia and serum lactic acid (LAC) and β₂-microglobulin (β₂-MG) in predicting the prognosis of patients with sepsis caused by infection in emergency department, so as to provide a basis for its clinical diagnosis and treatment.

A total of 90 patients with sepsis who were admitted to the Emergency Intensive Care Unit of Affiliated Hospital of North Sichuan Medical College from March 2020 to March 2021 were selected as the study subjects. Their survival within 28 days after diagnosis was analyzed retrospectively, and they were divided into either a death group (21 cases)or a survival group (69 cases) according to their prognosis. The basic data and laboratory indexes at the day of diagnosis were compared between the two groups, and the factors related to the prognosis were analyzed. Receiver operating characteristic (ROC) curve analysis was performed to assess their value in predicting the prognosis of the patients.

The proportions of patients with diabetes and chronic kidney disease and the acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score at the day of diagnosis were 42.86% (9/21), 47.62% (10/21), and (26.72±5.34) in the death group, respectively, which were significantly higher than the corresponding values in the survival group (P＜0.05). Blood ammonia and serum LAC, β₂-MG, and procalcitonin (PCT) levels were (115.56±38.17) μmol/L,(3.87±0.92) mmol/L, (6.91±1.32) mg/L, and (3.96±0.66)μg/L in the death group, respectively, which were higher than the corresponding values in the survival group (P＜0.05). Logistic multiple regression analysis showed that APACHE Ⅱ score, blood ammonia, and serum LAC and β₂-MG at the day of diagnosis were independent risk factors for the death of patients with sepsis (P＜0.05). The area under the ROC curve (AUC^ROC) values of APACHE Ⅱ score, blood ammonia, and serum LAC and β₂-MG in predicting the prognosis of the patients with sepsis were 0.705, 0.827, 0.663, and 0.815, respectively (P＜0.05), of which the AUC^ROC of blood ammonia was the highest, under the best boundary value, β₂-MG had the highest sensitivity, and LAC had the highest specificity.

Serum ammonia and serum LAC and β₂-MG have appreciated auxiliary values for early prediction of the prognosis of patients with sepsis caused by infection in emergency department. Clinicians should flexibly use a variety of markers according to their respective advantages to increase the prediction efficiency so as to improve the prognosis of such patients.