Cerebral oxygen monitoring during orthopedic surgery in the semi-sitting (beach-chair) position

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

Observational Akdeniz University · NCT07270341

We will see if noninvasive brain oxygen readings (NIRS) match routine heart rate, invasive arterial pressure, end-tidal CO2, and arterial blood gas changes in adults having orthopedic surgery in the semi-sitting position.

Quick facts

Study typeObservational
Enrollment40 (estimated)
Ages18 Years and up
SexAll
SponsorAkdeniz University Academic / other
Locations2 sites (Antalya and 1 other locations)
Trial IDNCT07270341 on ClinicalTrials.gov

What this trial studies

This prospective observational cohort continuously records cerebral oxygenation with near-infrared spectroscopy (NIRS) alongside routine noninvasive monitors and invasive arterial pressure during orthopedic operations performed in the semi-sitting (beach-chair) position. Investigators will compare NIRS values to heart rate, invasive mean arterial pressure, end-tidal carbon dioxide, and arterial blood gas results to determine correlations and temporal relationships. The study will also examine whether comorbidities such as diabetes, obesity, and hypertension are associated with cerebral perfusion parameters. No experimental interventions are applied beyond standard anesthetic and surgical care.

Who should consider this trial

Good fit: Adults (age ≥18) who are ASA physical status I–III, scheduled for orthopedic surgery in the semi-sitting position at Akdeniz University Hospital, and who provide informed consent.

Not a fit: Patients with prior cerebral ischemia, head trauma, previous neurosurgery, documented carotid stenosis ≥90%, prior neck surgery, children, or those who do not consent are unlikely to benefit from this observational monitoring protocol.

Why it matters

Potential benefit: If successful, the results could help clinicians detect early cerebral hypoperfusion and improve monitoring to reduce neurological complications during beach-chair orthopedic surgery.

How similar studies have performed: Previous studies using NIRS during sitting or beach-chair procedures have shown it can detect cerebral desaturation events, but correlations with standard hemodynamic measures have been inconsistent and are not fully established.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

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

Exclusion Criteria:

* 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

Where this trial is running

Antalya and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Cerebral PerfusionCerebral OxygenationHemodynamic MonitoringSemi-sitting PositionOrthopedic Surgical Procedurescerebral perfusionsemi-sitting positionorthopedic surgery
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.