Prognostic Value of Admission Blood Lactate for Predicting 28-Day Mortality in Patients With Septic Shock: A Prospective Pilot Study

Background Septic shock is a leading cause of mortality in intensive care units. Blood lactate is a key biomarker of tissue hypoperfusion; however, the prognostic value of a single initial lactate measurement remains debated. This study aimed to evaluate the predictive value of admission blood lactate levels for 28-day mortality in patients with septic shock. Methods A prospective, descriptive, and analytical pilot study was conducted, including 41 patients admitted for septic shock to a multidisciplinary intensive care unit in Rabat, Morocco, over a six-month period. Demographic, clinical, and biological data, including blood lactate levels at admission, were collected. The association between initial lactate and 28-day mortality was analyzed using non-parametric tests, receiver operating characteristic (ROC) curve analysis, and logistic regression. Results The mean age of patients was 60.9 years, with a male-to-female ratio of 1.27 (23 men (56.1%) and 18 women (43.9%)). The overall 28-day mortality rate was 56.1% (n = 23). Median admission lactate levels were higher in non-survivors (3.9 mmol/L; n = 23 (56.1%)) than in survivors (2.35 mmol/L; n = 18 (43.9%)), although this difference was not statistically significant (p = 0.231). The ROC curve showed poor discriminative performance (AUC = 0.610; p = 0.227). Logistic regression analysis did not identify admission lactate as an independent predictor of mortality. Conclusion Although higher lactate levels were observed in deceased patients, admission blood lactate alone demonstrated limited prognostic value for predicting 28-day mortality in this cohort of septic shock patients. Lactate interpretation should be dynamic and integrated into a comprehensive clinical assessment.