Investigation of risk factor for mortality in patients with HİGH lactate levels in the emergency department

Summary: It is known that lactate level is elevated in many critical or non-critical disease. Many studies have shown that lactate elevation is critical laboratory test for predicting mortality In this study we aimed to reveal the risk factors for mortality (age, gender, main cause of high lactate level, admission vitals, etc.) of patient admitted to emergency room critical care areas. Method and Materials: Patients over the age of 18 who applied to the critical areas (monitored observation and resusitation unit) in the emergency medicine department of Dokuz Eylül University between 1 October 2021 and 31 January 2022 and who were found to have high lactate in the blood gas analysis performed in the first hour of their application were included in the study. 30 day mortality of the patients was evaluated. Results: 979 patients with lactate level>2.5 mmol/L were included in the study. %56,7 of the patients were male and median age were 72 years (60-80). 30 days mortality of the patient was determined as %10,4 (n=102). The patients who died older, peripheral oxygen saturations, systolic and diastolic blood pressures were lower and pulse, shock index and respiratory rate were higher. The patients who died lactate and base excess levels are higher and pH and bicarbonate levels were lower. Mortality was found to be %3,6 (reference group) in patient with a decrease of more than %50 in the control lactate measurement and %9.6 in patients with a decrease between %10-49 (OR:2.851), %20.8 in patients with a %10 increase or decrease (OR:7.047), %26.7 in patients with a %10-49 increase (OR:9.737) and %40.7 in patients with a %50 or more increase. In patients who dien and had a bad outcome, the area under the curve of the lactate level measured in the control was 0,804. This value was greater than reference lactate and lactate clearance. A control lactate level of 3,15 mmol/L was calculated to ve %81,3 sensitivity and %69,7 spesificity in predicting mortality. It was found that patients who were started on vasopressors and treated with IMV and antibiotics had a higher mortality. It was found that those with the last diagnosis of ACS died 2.3 times, those with septic shock 4.1 times and those with AKI 4.3 times more. Conclusion: Patients vital signs, laboratory values, lactate clearence and parameters in their final diagnosis should be consider. Control lactate level >3,15 mmol/L is the most important laboratory test for predicting mortality. Key words: Lactate, lactate clearence, unselected patient, emergency department, mortality