Introduction

Septic shock remains a major cause of morbidity and mortality in intensive care units worldwide, despite substantial advances in early recognition, antimicrobial therapy, and hemodynamic resuscitation strategies [1,2].

Blood lactate has long been recognized as a key biomarker of tissue hypoperfusion and disease severity in sepsis and septic shock [3,4]. Elevated lactate levels may reflect impaired oxygen delivery, mitochondrial dysfunction, or stress-related metabolic alterations and are therefore widely used for early risk stratification and clinical decision-making in critically ill patients [3]. International guidelines, including the Surviving Sepsis Campaign, recommend lactate measurement as part of the initial evaluation and resuscitation of patients with suspected septic shock [2].

Several studies have demonstrated an association between elevated admission lactate levels and increased mortality in patients with sepsis, both in emergency department and intensive care settings [5,6]. However, the interpretation of lactate values remains complex, as hyperlactatemia may occur in the absence of overt hypoperfusion and may be influenced by multiple pathophysiological mechanisms [7]. As a result, the prognostic value of a single lactate measurement obtained at admission continues to be debated.

Growing evidence suggests that the prognostic relevance of lactate is substantially enhanced when assessed dynamically rather than as a static value [8]. Serial lactate measurements and lactate clearance over time have been shown to better reflect the adequacy of resuscitation and to be more strongly associated with patient outcomes than an isolated baseline value [9,10].

In this context, the present study aimed to evaluate the prognostic value of admission blood lactate levels for predicting 28-day mortality in patients with septic shock admitted to a multidisciplinary intensive care unit.