Clinical trial NCT06566690: The Association Between Sensory Block Level, Oxygen Therapy, and ORi in Varicose Vein Patients Undergoing Spinal Anesthesia (ORi: Oxygen Reserve Index)
Official title: Association Between Sensory Block Level, Oxygen Therapy, and ORi in Varicose Vein Patients Undergoing Spinal Anesthesia: A Correlation Study
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Hyperoxia
Hypoxia
Keywords: hyperoxia
hypoxia
oxygen therapy
spinal anaesthesia
Lead sponsor: Kocaeli University
Sponsor class: OTHER
First posted: 2024-08-22
Enrollment: 56
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
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

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.

Eligibility criteria: 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

Primary outcomes:
measure: 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).
timeFrame: 9 months
Secondary outcomes:
Other outcomes:
Locations:
city: Kocaeli
country: Turkey
facility: Kocaeli University
Study officials:
References:
citation: Scheeren TWL, Belda FJ, Perel A. The oxygen reserve index (ORI): a new tool to monitor oxygen therapy. J Clin Monit Comput. 2018 Jun;32(3):379-389. doi: 10.1007/s10877-017-0049-4. Epub 2017 Aug 8.