This prospective, observational study investigates the relationship between early oxygen exposure and oxidative stress in adult intensive care unit patients with sepsis or septic shock. Fraction of inspired oxygen (FiO₂) administered during the first 24 hours of ICU admission will be recorded and analyzed in relation to changes in the uric acid/albumin ratio (UAR), a biomarker reflecting oxidative burden and inflammation. Serum uric acid and albumin levels will be measured at baseline and at 24 hours, and the percentage change in UAR will be calculated. Secondary analyses will examine associations between UAR changes, oxygenation indices, and 28-day mortality. The study aims to determine whether higher FiO₂ exposure is associated with increased oxidative stress and to evaluate the potential role of UAR as a clinically accessible marker of oxygen-related oxidative injury in septic ICU patients.

Inclusion Criteria:

• Adult patients aged 18-65 years
• Patients undergoing elective septorhinoplasty
• Surgery performed under general anesthesia
• Complete recording of early postoperative VAS pain scores, Aldrete scores, NUDES scores, and vital signs in the Post-Anesthesia Care Unit (PACU)
• Preoperative complete blood count (hemogram) performed within 30 days prior to surgery
• Clinical records and hospital information system data that are complete, accessible, and adequate for analysis

Exclusion Criteria:

• Patients undergoing emergency surgery
• Septorhinoplasty combined with additional major surgical procedures (e.g., advanced ENT or maxillofacial surgery)
• Presence of known hematological disease, active infection, immunosuppressive therapy, or advanced liver or renal failure
• Chronic opioid use or regular analgesic medication use in the preoperative period
• History of significant clinical events between the preoperative hemogram and surgery that could alter inflammatory status (e.g., infection, hospitalization, additional surgery)
• Incomplete or missing data regarding preoperative hemogram parameters or PACU pain scores

The study population consists of adult patients aged 18-65 years who undergo elective septorhinoplasty under general anesthesia. All participants are managed according to standard clinical practice and are admitted to the Post-Anesthesia Care Unit (PACU) postoperatively, where early pain assessments and routine clinical monitoring are performed. Eligible patients have a complete preoperative hemogram obtained within 30 days prior to surgery and comprehensive postoperative records, including pain scores and vital signs. Patients with conditions or treatments that could significantly affect inflammatory markers or pain perception are excluded to ensure a homogeneous study population