The Association Between Sensory Block Level, Oxygen Therapy, and ORi in Varicose Vein Patients Undergoing Spinal Anesthesia (ORi: Oxygen Reserve Index) (ORi)

March 6, 2026 updated by: Volkan Alparslan, Kocaeli University

Association Between Sensory Block Level, Oxygen Therapy, and ORi in Varicose Vein Patients Undergoing Spinal Anesthesia: A Correlation Study

The assessment of peripheral capillary oxygen saturation (SpO2) by pulse oximetry has become standard in perioperative care for the detection of hypoxaemia. The oxygen reserve index (ORI) can provide an early warning of deteriorating oxygenation long before a change in SpO2 occurs, reflect the response to oxygen administration, facilitate oxygen titration and prevent unwanted hyperoxia. The combination of ORI with pulse oximetry can help to accurately adjust inhaled oxygen concentration and prevent hypo- and hyperoxaemia. In spinal anaesthesia, neuraxial blockade can cause paralysis of accessory respiratory muscles and theoretically lead to bronchospasm. Therefore, in this study, the investigators planned to perform oxygen saturation monitoring using two modalities. The investigators wanted to investigate the correlation between ORI, SpO2, oxygen therapy and the degree of sensory block.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The assessment of peripheral capillary oxygen saturation (SpO2) by pulse oximetry has become standard in perioperative care for the detection of hypoxaemia. The oxygen reserve index (ORI) can provide an early warning of deteriorating oxygenation long before a change in SpO2 occurs, reflect the response to oxygen administration, facilitate oxygen titration and prevent unwanted hyperoxia. The combination of ORI with pulse oximetry can help to accurately adjust inhaled oxygen concentration and prevent hypo- and hyperoxaemia. In spinal anaesthesia, neuraxial blockade can cause paralysis of accessory respiratory muscles and theoretically lead to bronchospasm. The respiratory effects of neuraxial blockade up to mid-thoracic level are minimal in patients without lung disease. While the intercostal muscles may be paralysed by thoracic block, diaphragmatic function is preserved. Therefore, in this study, the investigators planned to perform oxygen saturation monitoring using two modalities. The investigators wanted to investigate the correlation between ORI, SpO2, oxygen therapy and the degree of sensory block.

Study Type

Observational

Enrollment (Actual)

56

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

This study aims to include ASA I-II patients aged 18-65 years scheduled for elective varicose vein surgery, with the sample size to be determined by a pilot study

Description

Inclusion Criteria:

- ASA I-II

Exclusion Criteria:

  • Chronic Obstructive Pulmonary Disease (COPD)
  • Smoking history of >30 pack-years
  • Cancer patients
  • Interstitial lung disease patients
  • Patients with Body Mass Index (BMI) >30 kg/m²
  • Patient refusal of spinal anesthesia
  • Refusal to participate in the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The primary outcome of this study is to assess the correlation between the need for oxygen therapy, the ascension of sensory block level, and changes in Oxygen Reserve Index (ORi).
Time Frame: 9 months
The primary outcome measure of this study is to evaluate the potential correlation between three variables: the need for supplemental oxygen therapy, the cephalad progression of sensory block level, and fluctuations in oxygen reserve index (ORi) values.
9 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Kocaeli University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 29, 2024

Primary Completion (Actual)

February 10, 2026

Study Completion (Actual)

March 6, 2026

Study Registration Dates

First Submitted

August 20, 2024

First Submitted That Met QC Criteria

August 20, 2024

First Posted (Actual)

August 22, 2024

Study Record Updates

Last Update Posted (Actual)

March 9, 2026

Last Update Submitted That Met QC Criteria

March 6, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2024-KAEK-02

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Hypoxia

Clinical Trials on Addition of ORi monitoring to SpO2 monitoring

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Malaysia

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe