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

Last updated: March 6, 2026
Sponsor: Kocaeli University
Overall Status: Completed

Phase

N/A

Condition

Occlusions

Vascular Diseases

Varicose Veins

Treatment

Addition of ORi monitoring to SpO2 monitoring

Clinical Study ID

NCT06566690
2024-KAEK-02
  • Ages 18-65
  • All Genders
  • Accepts Healthy Volunteers

Study Summary

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.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • ASA I-II

Exclusion

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 Design

Total Participants: 56
Treatment Group(s): 1
Primary Treatment: Addition of ORi monitoring to SpO2 monitoring
Phase:
Study Start date:
August 29, 2024
Estimated Completion Date:
March 06, 2026

Study 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.

Connect with a study center

  • Kocaeli University

    Kocaeli,
    Turkey

    Site Not Available

  • Kocaeli University

    Kocaeli,
    Turkey (Türkiye)

    Site Not Available

  • Kocaeli University

    Kocaeli 306970,
    Turkey (Türkiye)

    Site Not Available

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