Serum Lactate Levels and Their Correlation With Hospital Outcomes in ICU Patients With Shock: A Cross-Sectional Study at a Tertiary Care Center.

Background And Aim: Shock is a life-threatening state characterized by inadequate tissue perfusion to meet metabolic demand, leading to organ failure and death. Serum lactate, a byproduct of anaerobic metabolism, has been identified as a significant biomarker for assessing shock severity and predicting outcomes. This study aimed to evaluate the correlation between serial serum lactate levels and hospital outcomes in patients with shock admitted to the ICU at Manik Hospital.

Methods: A prospective observational study was conducted, including 124 adult patients diagnosed with shock and admitted to the ICU between April 2023 and December 2023. Serum lactate levels were measured at admission and 24 hours later. Outcomes assessed included mortality, mechanical ventilation, ICU stay duration, and shock index. Data were analyzed using descriptive and inferential statistics, including Pearson correlation and receiver operating characteristic (ROC) curves.

Results: The study participants had a mean age of 50.7 years, with hypovolemic shock being the most common condition, affecting 61.3% (n=76). A moderate positive correlation was found between serum lactate levels and the shock index at both admission (r=0.273) and 24 hours (r=0.293) (p<0.001). Elevated lactate levels at both time points were significantly associated with increased mortality and the need for mechanical ventilation (p<0.001). At admission, lactate predicted mortality with an area under the curve (AUC) of 0.765, which increased to 0.848 at 24 hours. Lactate also showed good predictive power for the need for mechanical ventilation, with AUC values of 0.737 at admission and 0.664 at 24 hours.

Conclusions: Elevated serum lactate levels, both at admission and 24 hours, were identified as strong predictors of mortality, mechanical ventilation, and prolonged ICU stay in shock patients. Serial lactate measurements were found to provide valuable prognostic information, aiding in early risk stratification and personalized patient management. Further research was recommended to validate these findings across multiple centers and explore the role of lactate clearance in predicting recovery.