Preoperative ROX Index and Postoperative Hypoxemia in Bariatric Surgery

NCT07303205 | Not Yet Recruiting

• 1 other identifier: erkan rox indeksi
• Study Type: observational
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Hypoxemia

Outcome Measures

Primary Outcomes (1)

• Early Postoperative Hypoxemia

  Hypoxemia defined as SpO₂ \< 92% or new oxygen requirement within the first postoperative hours.

  Postoperative 0-12 hours

Interventions

Preoperative ROX Index Assessment OTHER

Participants will undergo a preoperative assessment including measurement of the ROX index (SpO₂/FiO₂ divided by respiratory rate) before bariatric surgery. No treatment or study-related intervention will be applied; all perioperative care will follow routine clinical practice.

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adult patients scheduled for elective bariatric surgery, including laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass. All participants are obese (BMI ≥ 35 kg/m²) and evaluated preoperatively in the anesthesia clinic prior to surgery.

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Istinye University: lead

Study Sites (1)

Istinye Üniversity

Istanbul, Merkez Mahallesi, 34250, Turkey (Türkiye)

Location

Related Publications (3)

• Helmy MA, Mostafa MS, Saber AT, Ali MA, Milad LM. Erector Spinae Plane Block and its Impact on Postoperative Diaphragmatic Dysfunction in Morbidly Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy: A Double-Blind Randomized Control Trial. Obes Surg. 2025 Dec;35(12):5228-5236. doi: 10.1007/s11695-025-08337-y. Epub 2025 Nov 4.

  PMID: 41188672 RESULT

• Wang X, Guo K, Sun J, Yang Y, Wu Y, Tang X, Xu Y, Chen Q, Zeng S, Wang L, Liu S. Semirecumbent Positioning During Anesthesia Recovery and Postoperative Hypoxemia: A Randomized Clinical Trial. JAMA Netw Open. 2024 Jun 3;7(6):e2416797. doi: 10.1001/jamanetworkopen.2024.16797.

  PMID: 38941098 RESULT

• Lee S, Hong H, Cho H, Lee SW, You AH, Kang HY, Park SW, Kim MK, Choi JH. Association between preoperative oxygen reserve index and postoperative pulmonary complications: a prospective observational study. Korean J Anesthesiol. 2025 Jun;78(3):224-235. doi: 10.4097/kja.24420. Epub 2025 Feb 17.

  PMID: 40468628 RESULT

MeSH Terms

Conditions

Hypoxia

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Central Study Contacts

ilke dolgun

CONTACT

+905555485632; ilkeser2004@gmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assoc. prof

Study Record Dates

• First Submitted: December 11, 2025
• First Posted: December 24, 2025
• Study Start: December 25, 2025
• Primary Completion: February 25, 2026
• Study Completion: March 1, 2026
• Last Updated: December 24, 2025

Record last verified: 2025-12

Locations

TU (1)