Investigators predict that the information that can be obtained in terms of renal functions before clinical development in sepsis patients can be valuable in terms of guiding treatment algorithms, planning renal replacement therapies and using drugs that are toxic to the kidneys.

Despite the developments in Intensive Care Units (ICU), mortality and morbidity rates due to sepsis and septic shock are still high and it is seen as one of the major causes of death in ICU patients. Acute kidney injury (AKI) is a common disease worldwide and is seen in approximately 60% of intensive care hospitalizations. Diagnosis is generally made by the increase in serum creatinine level. Although it is a basic marker for AKI in current conditions, its levels can be misleading in clinical practice, especially in sepsis patients characterized by clinical conditions such as multiple organ failure. For these reasons, there is a need for new and applicable biomarkers that can be used in planning organ support treatments that can be applied to renal function in sepsis patients.

The utility of a new marker called presepsin in disease course, prognosis determination and sepsis-associated AKI clinic has been demonstrated. There are studies showing that neutrophil gelatinase-associated lipocalin (NGAL) is more valuable when compared to creatinine in patients with sepsis-associated AKI. Proenkephalin is a new biomarker studied, and it has been studied with NGAL in patients with cardiogenic shock, and it has been shown to have a place in the prediction of AKI in patients with cardiogenic shock. Significant elevation of syndecan-1 in acute kidney injury has been demonstrated in animal studies and clinical studies. In the literature, as far as investigators know, proenkephalin and syndecan-1 have not been studied in terms of AKI in sepsis patients.

In our study, investigators plan to investigate the role of biomarkers such as presepsin, syndecan-1, NGAL, and proenkephalin in predicting the risk of developing AKI in sepsis patients. The relevant markers will be studied from the blood sample taken from the patients diagnosed with sepsis at the time of diagnosis, and the results will be analyzed in terms of markers that may be more useful in predicting the development of AKI in patients. In addition, investigators aim to obtain clinical information by investigating whether these biomarkers have predictive properties on disease prognosis and mortality.

Inclusion Criteria:

1. Patients diagnosed with sepsis and septic shock according to the "The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)" guideline.
2. Signing of the Informed Consent Form by the patient or his legal representative.

Exclusion Criteria:

1. Patients under 18 years of age.
2. They are pregnant.
3. Malignant patients in the terminal period with no expected survival.
4. The Informed Consent Form is not signed by the patient or patient's relative.
5. Sepsis and septic shock patients admitted from another hospital under vasopressor or on mechanical ventilator.
6. Patients who develop brain damage and multi-organ failure after cardiopulmonary resuscitation.
7. Chronic renal failure patients receiving dialysis treatment.

Patients diagnosed with sepsis and septic shock according to the "The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3)" guideline.