Preoperative ROX Index and Postoperative Hypoxemia in Bariatric Surgery

Predictive Value of the Preoperative ROX Index for Early Postoperative Hypoxemia in Bariatric Surgery Patients: A Prospective Observational Cohort Study

This prospective observational study evaluates whether the preoperative ROX index can predict early postoperative hypoxemia in patients undergoing bariatric surgery. Preoperative ROX measurements, along with ARISCAT and STOP-Bang scores, will be assessed for their association with hypoxemia occurring within the first 12 postoperative hours.

Inclusion Criteria:

• Adults aged 18-65 years
• Scheduled for elective bariatric surgery (laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass)
• Body mass index (BMI) ≥ 35 kg/m²
• ASA physical status I-III
• Able and willing to provide written informed consent

Exclusion Criteria:

• Acute respiratory failure, pneumonia, or active pulmonary infection
• Receiving oxygen therapy or respiratory support (nasal cannula, CPAP, BiPAP, or high-flow oxygen) preoperatively
• Preoperative SpO₂ < 88% on room air
• Significant cardiac arrhythmia, severe heart failure (NYHA class III-IV), or hemodynamic instability
• Pregnancy, active malignancy, or current immunosuppressive therapy
• Inability to complete postoperative follow-up or early discharge before 12-hour assessment