An evaluation of serial blood lactate measurement as an early predictor of shock and its outcome in patients of trauma or sepsis

CONTEXT: Attainment of hemodynamic parameters to within a normal range may leave patients in compensatory shock. In such patients, serial blood lactate evaluation can be useful in predicting shock. AIMS: To ascertain the role of serum lactate as a predictor of shock and its outcome in patients of trauma and sepsis. SETTINGS AND DESIGN: A prospective, non-interventional study. MATERIALS AND METHODS: The study included 50 patients (5 to 60 years old) of trauma admitted within 12 hours of injury and patients of suspected or proven sepsis. Those with chronic medical illnesses, alcohol intoxication, or poisoning were excluded. Blood lactate levels were analyzed at admission and 12, 24, and 36 hours of inclusion with records of corresponding hemodynamic variables, investigations, and interventions. The outcome was recorded as survival or non-survival. STATISTICAL ANALYSIS USED: Statistical analysis was done with a student's t test and repeated measure ANOVA (Analysis of Variance). RESULTS: An analysis revealed higher mean lactate levels in non-survivors as compared with survivors. Mean lactate levels in non-survivors did not attain normal levels, while that of survivors reached normal levels by 24 hrs in trauma patients and 36 hrs in sepsis patients. The predicted mortality rates by a lactate level >40 mg/dl at admission, 12, 24, and 36 hours were 52.6%, 61.5%, 83.3%, and 100%, respectively for both the subgroups combined. Non-survivors had a higher incidence of MODS (Multi Organ Dysfunction Syndrome). CONCLUSIONS: Serial lactate values followed over a period of time can be used to predict impending complications or grave outcome in patients of trauma or sepsis. Interventions that decrease lactate values to normal early may improve chances of survival and can be considered effective therapy. Lactate values need to be followed for a longer period of time in critical patients.