Evaluation of Cerebral Oxygenation During Orthopedic Surgeries Performed in the Beach Chair Position Under General Anesthesia

NCT07270341 | Recruiting

• 1 other identifier: TBAEK-727
• Study Type: observational
• Target: 40
• Locations: 1 country
• Sites: 2

Brief Summary

The goal of this observational study is to determine the correlation between cerebral oxygenation values measured by near-infrared spectroscopy (NIRS) and other routine monitoring parameters in patients placed in the semi-sitting position. The primary questions investigated are : Do NIRS values correlate with heart rate, invasive mean arterial pressure, and end-tidal carbon dioxide? Do NIRS values reflect changes observed in arterial blood gas analysis? Are cerebral perfusion-related parameters associated with patients' comorbidities such as diabetes, obesity, and hypertension? Researchers will compare routine noninvasive monitoring (heart rate, blood pressure, peripheral oxygen saturation) with invasive arterial monitoring and NIRS to assess whether NIRS provides additional information for evaluating cerebral perfusion. Participants will be monitored for: Heart rate Invasive mean arterial pressure End-tidal carbon dioxide Arterial blood gas changes Cerebral oxygenation with NIRS Patients' comorbidities (e.g., diabetes, obesity, hypertension) will also be recorded, and their association with perfusion-related parameters will be analyzed.

Conditions

Cerebral Perfusion; Cerebral Oxygenation; Semi-sitting Position; Hemodynamic Monitoring; Orthopedic Surgical Procedures

Keywords

cerebral perfusion; semi-sitting position; orthopedic surgery; cerebral oxygenation

Outcome Measures

Primary Outcomes (2)

• Correlation Between Cerebral Oxygenation (rSO₂) Measured by NIRS and Systemic Oxygenation

  The correlation between intraoperative cerebral oxygenation (regional cerebral oxygen saturation, rSO₂) (%)-measured non-invasively using near-infrared spectroscopy (NIRS) -and simultaneous systemic oxygenation assessed using arterial blood gas analysis, including: Arterial pH, PaO₂ (mmHg) and PaCO₂ (mmHg)

  From pre-induction baseline through post-induction and positional measurements, followed by repeated assessments every 30 minutes until the end of surgery.

• Correlation Between Cerebral Oxygenation (rSO₂) Measured by NIRS and Hemodynamic Parameters (Heart Rate and Blood Pressure)

  The correlation between intraoperative cerebral oxygenation (regional cerebral oxygen saturation, rSO₂) (%)-measured non-invasively using near-infrared spectroscopy (NIRS) -and systemic hemodynamic parameters. Systemic hemodynamic parameters will include: 1. Heart rate (beats per minute), monitored continuously via electrocardiography (ECG) 2. Noninvasive mean arterial pressure (mmHg), measured using an automated oscillometric device 3. Invasive mean arterial pressure (mmHg), obtained via an arterial catheter

  From pre-induction baseline through post-induction and positional measurements, followed by repeated assessments every 30 minutes until the end of surgery.

Secondary Outcomes (3)

• Association of Preoperatively Documented Hypertension with Intraoperative Low Cerebral Oxygenation (rSO₂) Measured by Near-Infrared Spectroscopy

  Preoperative period for comorbidity assessment and intraoperative period for cerebral oxygenation measurements (from pre-induction baseline to the end of surgery.

• Association of Preoperatively Documented Diabetes Mellitus with Intraoperative Low Cerebral Oxygenation (rSO₂) Measured by Near-Infrared Spectroscopy

  Preoperative period for comorbidity assessment and intraoperative period for cerebral oxygenation measurements (from pre-induction baseline to the end of surgery.

• Association of Preoperatively Documented Obesity with Intraoperative Low Cerebral Oxygenation (rSO₂) Measured by Near-Infrared Spectroscopy

  Preoperative period for comorbidity assessment and intraoperative period for cerebral oxygenation measurements (from pre-induction baseline to the end of surgery.

Study Arms (1)

Orthopedic Surgery Patients in Semi-sitting Position

ASA I-III patients undergoing orthopedic surgery in the semi-sitting position, monitored with NIRS, invasive arterial pressure, and routine parameters.

Diagnostic Test: Near-Infrared Spectroscopy (NIRS) Monitoring

Interventions

Near-Infrared Spectroscopy (NIRS) Monitoring DIAGNOSTIC_TEST

Cerebral oxygenation will be monitored using NIRS in addition to standard intraoperative monitoring (heart rate, invasive arterial pressure, end-tidal CO₂, and blood gas analysis).

Also known as: Invasive Arterial Catheterization, Routine intraoperative monitoring including heart rate, non-invasive blood pressure, peripheral oxygen saturation, and end-tidal CO₂.

Orthopedic Surgery Patients in Semi-sitting Position

Eligibility Criteria

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

Study Population

Adult patients (18 years and older, ASA I-III) undergoing orthopedic surgery in the semi-sitting position, monitored for cerebral oxygenation (NIRS), invasive arterial pressure, and routine intraoperative parameters.

You may qualify if:

• Patients scheduled for orthopedic surgery in the semi-sitting position
• ASA physical status I-III
• Voluntary participation with informed consent

You may not qualify if:

• Patients younger than 18 years
• Patients who do not provide consent
• History of cerebral ischemia
• History of head trauma
• Previous neurosurgical intervention
• Documented carotid stenosis ≥90%
• Previous neck surgery

Sponsors & Collaborators

• Akdeniz University: lead

Study Sites (2)

Akdeniz University Hospital

Antalya, 07070, Turkey (Türkiye)

RECRUITING

Akdeniz University Hospital

Antalya, 07070, Turkey (Türkiye)

RECRUITING

Related Publications (2)

• Yu S, Bloomquist D. Can resorbable screws effectively be used in fixating bilateral sagittal split osteotomies for mandibular advancement? A randomized controlled trial. J Oral Maxillofac Surg. 2014 Nov;72(11):2273-7. doi: 10.1016/j.joms.2014.04.033. Epub 2014 May 9.

  PMID: 25086478 BACKGROUND

• Carroll JJ, Marshall BDL, Rich JD, Green TC. Exposure to fentanyl-contaminated heroin and overdose risk among illicit opioid users in Rhode Island: A mixed methods study. Int J Drug Policy. 2017 Aug;46:136-145. doi: 10.1016/j.drugpo.2017.05.023. Epub 2017 Jun 1.

  PMID: 28578864 BACKGROUND

MeSH Terms

Interventions

Spectroscopy, Near-Infrared; Oxygen Saturation

Intervention Hierarchy (Ancestors)

Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis; Spectrum Analysis; Chemistry Techniques, Analytical; Investigative Techniques; Metabolism

Central Study Contacts

Nesil Coşkunfırat, Prof Dr (M.D.)

CONTACT

+905326873426; nesildgr@yahoo.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Prof Dr

Study Record Dates

• First Submitted: November 18, 2025
• First Posted: December 8, 2025
• Study Start: October 1, 2024
• Primary Completion (Estimated): May 30, 2026
• Study Completion (Estimated): May 30, 2026
• Last Updated: December 8, 2025

Record last verified: 2025-12

Locations

TU (2)