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

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

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT06566690
Acronym
ORi
Enrollment
56
Registered
2024-08-22
Start date
2024-08-29
Completion date
2026-03-06
Last updated
2026-03-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hyperoxia, Hypoxia

Keywords

hyperoxia, hypoxia, oxygen therapy, spinal anaesthesia

Brief 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.

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.

Interventions

DEVICEAddition of ORi monitoring to SpO2 monitoring

Integration of Oxygen Reserve Index (ORi) monitoring into standard SpO2 monitoring

Sponsors

Kocaeli University
Lead SponsorOTHER

Study design

Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frameDescription
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).9 monthsThe 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.

Countries

Turkey (Türkiye)

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 10, 2026