This clinical trial aims to determine if the type of intravenous fluid used for initial resuscitation affects the short-term outcomes of adult patients with sepsis who are treated in the emergency department.

The main questions it aims to answer are:

Does using Ringer's lactate instead of 0.9% sodium chloride (normal saline) reduce 24-hour mortality in patients with sepsis?

Does the type of fluid influence other short-term outcomes, such as the need for vasopressors, mechanical ventilation, hemodialysis, and length of hospital stay?

Researchers will compare two groups of participants:

• The Ringer's lactate group (intervention group)
• The 0.9% sodium chloride group (control group).

Participants will:

• Receive either Ringer's lactate or normal saline for initial fluid resuscitation as part of standard sepsis care.
• They will be observed for 24 hours to assess survival and other early outcomes.

This prospective, single-center, randomized, double-blind, controlled clinical trial aims to compare the effects of Ringer's lactate and 0.9% sodium chloride (normal saline) solutions for initial fluid resuscitation in adult patients with sepsis who are treated in the emergency department. The study is conducted in accordance with the Surviving Sepsis Campaign's 2021 guidelines, which emphasize the importance of early and adequate crystalloid resuscitation in sepsis management. Although both solutions are widely used in clinical practice, evidence regarding their comparative effects on short-term mortality and organ dysfunction is inconsistent. This study seeks to provide prospective, blinded data to clarify whether fluid type influences early outcomes in patients with sepsis.

Participants who meet eligibility criteria will be randomized in a 1:1 ratio using a computer-generated sequence prepared by an independent staff member. To ensure blinding, study fluids will be provided in identical coded containers, and patients, treating clinicians, and investigators will remain unaware of the assigned fluid type throughout the study period.

The assigned study fluid will be administered intravenously as an initial bolus according to clinical judgment. After completion of the initial bolus, all subsequent fluid therapy and additional treatments will follow standard institutional practice at the discretion of the treating physician.

If clinical circumstances require breaking the study blind for patient safety reasons, the investigator will document the reason and unblind the allocation. There will be no delay in clinical management as a result of study participation.

Inclusion Criteria:

• Adult male or female patients (≥18 years of age) presenting to the emergency department.
• Diagnosed or suspected sepsis secondary to an infectious cause.
• Provision of written informed consent by the patient, or if the patient is unable to consent, by a first-degree relative or legally authorized representative.

Exclusion Criteria:

• Age under 18 years old.
• Pregnant women.
• Informed consent was not obtained from the patient or their first-degree relative/legal guardian.
• Patients who are receiving cardiopulmonary resuscitation (CPR) or who require endotracheal intubation at the time of presentation.
• Patients with severe volume depletion unrelated to sepsis (e.g., diabetic ketoacidosis, burns, or active gastrointestinal bleeding).
• Patients with severe hyperkalemia (serum potassium level of at least 6.5 mmol/L with ECG changes).
• Patients with hypotension that is not related to sepsis (e.g., active hemorrhage or intracranial bleeding).
• Patients with clinical signs of pulmonary edema or congestive heart failure.
• Cases in which the treating physician determines that one isotonic crystalloid (Ringer's lactate or 0.9% NaCl) is clearly superior to the other due to clinical condition or comorbidities.
• Cases in which the treating physician anticipates that fluid therapy might be delayed due to study participation.
• Patients requiring immediate hospital or ICU admission before completion of initial emergency department resuscitation.
• Patients with sepsis sources requiring urgent invasive intervention known to directly affect mortality (e.g., an undrainable abscess or osteomyelitis).

Additional exclusion criteria based on the contraindications listed in the Ringer's lactate product information:,

• Known hypersensitivity to sodium lactate.
• Extracellular hyperhydration or hypervolemia.
• Severe renal failure with oliguria or anuria.
• Decompensated heart failure.
• Hypercalcemia.
• Metabolic alkalosis or severe metabolic acidosis.
• Conditions associated with impaired lactate metabolism, such as lactic acidosis, severe liver failure, and cirrhosis with ascites.
• Current use of digitalis preparations (e.g., digoxin).

De-identified individual participant data (IPD) underlying the study results will be shared upon reasonable request after publication. Shared data will include demographic, treatment, and outcome variables. Access will be granted to qualified researchers with ethics committee approval and a sound research proposal.

De-identified individual participant data (IPD) and supporting documents will be available beginning 6 months after publication of the main results and will remain available for 5 years thereafter. Requests received after this period will be evaluated on a case-by-case basis.

Data will be shared with qualified researchers upon reasonable request. Interested investigators must submit a brief research proposal describing study aims, statistical analysis plan, and data protection procedures. Access will be granted after approval by the institutional ethics committee. The de-identified dataset and relevant documents will be shared electronically via a secure data transfer platform.