The goal of this observational study is to learn if the Diastolic Shock Index (DSI) and initial lactate can predict occult vasoplegia in adults with normotensive sepsis. Normotensive sepsis occurs in patients who have an apparently normal mean arterial pressure but may have impaired vascular tone.

The main questions it aims to answer are:

• Can an elevated DSI at admission predict the initiation of vasopressors (norepinephrine) within the first 6 hours of intensive care unit stay?
• How does the combination of initial DSI and lactate perform compared to each marker alone in predicting hemodynamic deterioration? Researchers will compare patients with an elevated DSI to those with a normal DSI to see if this index identifies those who will progress to circulatory shock.Since this is a retrospective cohort study using existing medical records, participants will not be asked to perform any tasks. Researchers will analyze anonymized data, such as heart rate, blood pressure, and lactate levels already recorded in the institutional database.

Inclusion Criteria:

• Patients over 18 years of age.
• Diagnosis of sepsis upon admission according to Sepsis-3 criteria (suspected or confirmed infection plus an increase in SOFA score >2).
• Mean Arterial Pressure (MAP) during the first hour >=65 mmHg.
• No vasopressor infusion at the time of initial assessment (Time 0)

Exclusion Criteria:

• Patients who died within the first 24 hours of admission.
• Patients transferred out of the unit within the first 24 hours
• Patients who were already receiving vasopressor support in the pre-hospital setting or the emergency department before ICU admission.

The study population consists of adult patients admitted to the Intensive Care Unit (ICU) of Hospital H+ Querétaro. The cohort includes individuals with a diagnosis of sepsis (Sepsis-3) who maintain a mean arterial pressure (MAP) >=65 mmHg without the need for vasopressors during their initial hour of admission. These patients are identified from an existing institutional database covering the period between January 1, 2024, and May 31, 2025. The population represents a specific group of critically ill patients who, despite appearing hemodynamically stable (normotensive), are at risk of rapid progression to overt circulatory collapse and vasoplegia.