Oxygenation in Posterior Stabilization Surgery

Factors Determining Oxygenation in Posterior Stabilization Surgery: The Role of Positioning and Mechanical Ventilation Parameters

This study aims to evaluate the effects of prone positioning on oxygenation, ventilation, and hemodynamic parameters in patients undergoing posterior stabilization surgery under general anesthesia. By comparing routine anesthesia and monitoring data obtained in the supine and prone positions, the study seeks to determine how positional changes influence respiratory mechanics and perioperative physiological stability.

Study Overview

• Status: Not yet recruiting
• Conditions: Oxygen Saturation; Oxygen
• Intervention / Treatment: Other: blood gase

Detailed Description

The prone position is frequently used during posterior stabilization surgery, yet it is associated with important physiological changes that may affect both respiratory and hemodynamic function under general anesthesia. Previous studies have shown that prone positioning may improve ventilation-perfusion matching, increase functional residual capacity, and enhance oxygenation. At the same time, position-related alterations in thoracic mechanics, airway pressures, venous return, and cardiovascular parameters may influence intraoperative management.

This study is designed to comprehensively assess the physiological effects of prone positioning in anesthetized patients undergoing posterior stabilization surgery. Routine anesthesia and monitoring data collected during mechanical ventilation will be analyzed and compared between the supine and prone positions. Particular focus will be placed on oxygenation, ventilation variables, respiratory mechanics, and hemodynamic parameters in order to evaluate the impact of positional change.

In addition, the study aims to identify which clinical and monitoring findings should be prioritized during anesthetic management of patients in the prone position. By clarifying the relationship between positioning and perioperative physiological responses, the study seeks to contribute to safer anesthetic practice and to support the maintenance of adequate oxygenation and hemodynamic stability throughout surgery.

• Study Type: Observational
• Enrollment (Estimated): 50

Contacts and Locations

• Study Contact: Name: HAVVA KOCAYİĞİT, Associate Professor; Phone Number: 905425950020; Email: havvakocayigit@gmail.com

Study Locations

• Turkey (Türkiye)
  • Karabük Province
    • Sakarya, Karabük Province, Turkey (Türkiye), 78000
      • Sakarya Universt

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

the study population consists of women reproductive age (18-80 years ) who are sheduled to undergo Posterior Stabilization Surgery under general anesthesia.

Description

Inclusion Criteria:

Patients aged 18 to 75 years Patients classified as ASA physical status I, II, or III according to the American Society of Anesthesiologists Patients undergoing posterior stabilization surgery Patients who voluntarily agreed to participate in the study Patients with a body mass index (BMI) <35 kg/m² Patients followed with a standard mechanical ventilation procedure

Exclusion Criteria:

• - ASA 4 olarak değerlendirilenler
• Anestezik ajan alerjisi olanlar
• Kanama diatezi bozukluğu olanlar
• Cerrahi süresi 3 saatin üstünde olanlar
• Bilinen ileri akciğer hastalığı olanlar (intertisyel akciğer hastalığı, ileri düzey KOAH, ileri düzey astım vb)
• VKI≥35 olanlar
• Obstrüktif uyku apne sendromu tanısı olanlar
• Toraks deformitesi olanlar
• Ciddi kalp yetmezliği öyküsü olanlar (EF<30)
• Şiddetli anemi öyküsü olanlar (Hg<8 mg/dl)
• Cerrahi operasyon sırasında kan transfüzyonu ihtiyacı olan hastalar

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
group supine; Retrospective evaluation of routine intraoperative anesthesia and monitoring parameters recorded while patients were in the supine position before prone positioning.	Other: blood gase; Arterial blood gas samples will be obtained from patients, and alveolar oxygenation ratios will be compared between the supine and prone positions.
group prone; Retrospective evaluation of routine intraoperative anesthesia and monitoring parameters recorded after patients were placed in the prone position during posterior stabilization surgery.	Other: blood gase; Arterial blood gas samples will be obtained from patients, and alveolar oxygenation ratios will be compared between the supine and prone positions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in alveolar oxygenation between supine and prone positions	The primary outcome of this study is to evaluate the difference in alveolar oxygenation between the supine and prone positions in patients undergoing posterior stabilization surgery. Arterial blood gas samples obtained during surgery will be used to compare oxygenation parameters measured in both positions and to assess the effect of positional change on oxygenation.	within 20 minutes after anesthesia induction

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in optic nerve sheath diameter between supine and prone positions	The secondary outcome is the comparison of optic nerve sheath diameter measurements obtained in the supine position and after positioning the patient prone during posterior stabilization surgery. This assessment is intended to evaluate the effect of positional change on optic nerve sheath diameter.	intraoperatively

Collaborators and Investigators

• Sponsor: Sakarya University

Publications and helpful links

General Publications

• Radstrom M, Loswick AC, Bengtsson JP. Respiratory effects of the kneeling prone position for low back surgery. Eur J Anaesthesiol. 2004 Apr;21(4):279-83. doi: 10.1017/s0265021504004053.

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): October 15, 2026
• Study Completion (Estimated): November 15, 2026

Study Registration Dates

• First Submitted: March 17, 2026
• First Submitted That Met QC Criteria: March 17, 2026
• First Posted (Actual): March 23, 2026

Study Record Updates

• Last Update Posted (Actual): March 23, 2026
• Last Update Submitted That Met QC Criteria: March 17, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: oxygenation; Posterior Stabilization Surgery; Mechanical Ventilation Parameters; optic nerve sheath diamater
• Additional Relevant MeSH Terms: Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Techniques, Respiratory System; Respiratory Function Tests; Blood Chemical Analysis; Clinical Chemistry Tests; Blood Gas Analysis
• Other Study ID Numbers: SAU-ANE-EG-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: This study will not share individual participant data. Data will be collected and analyzed solely for research purposes and will remain confidential in accordance with institutional and ethical guidelines

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No