The Changes of Tissue Oxygen Saturation Under Spinal Anesthesia

Study Overview
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Brief Summary
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Neuraxial anesthesia affords a less interventional way to desensitization of the lower body for surgical procedures. After introduction of neuraxial anesthesia, vasodilatation of body part below the anesthetic level is theoretically appeared as the sympathetic nerve efferent is blocked. The vasodilatation effect is related to hypotension, hypothermia, shivering and the response of volume redistribution. It is believed that vasodilatation leads to better regional tissue perfusion and better regional tissue oxygenation. Previous reports of laser doppler flowmetry and thermography showed their effectiveness on monitoring blocked level but they were not easily available in the operation room. Recently Near-infrared spectroscopy(NIRS) demonstrates real-time tissue oxygen saturation(rSO2) which is applied generally in non-invasive brain oximeter. We use NIRS in spinal anesthesia to monitor the tissue oxygenation change over the upper and lower limbs during the induction of neuraxial anesthesia.

Detailed Description
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In patients who were planned to receive an operation with intrathecal anesthesia, NIRS (INVOS Cerebral Oximeter Model 5100B; Somanetics, Troy, MI, USA) with two adhesive patches was used to monitor rSO2. One patch was applied over the biceps brachii muscle,(the body part above the anaesthetic level), and the other patch was applied over the medial side of the gastrocnemius muscle of the non-surgical leg,(the body part below the anaesthetic level). In both extremities, rSO2 was monitored continuously and recorded every minute from before intrathecal bupivacaine injection until 15 min after injection. Isobaric bupivacaine 0.5% 10-15 mg was injected intrathecally and the level of anaesthesia was examined 10 min later by loss of cold sensation to alcohol swab by an anaesthetist not involved in the study. the changes of rSO2 of upper and lower extrimities were recorded and analysed.

Official Title
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The Changes of Tissue Oxygen Saturation Under Spinal Anesthesia

Conditions
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Anesthesia

Intervention / Treatment
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* Other: tissue oxygen saturation, spinal anesthesia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients who receive operations under spinal anesthesia Exclusion Criteria: neurological, cardiovascular diseases

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 1Tissue oxygenation change<br>Spinal anesthesia may result different changes of tissue oxygenation in blocked area ( upper extrimities ) and non-blocked area ( lower extrimities). The changes of tissue oxygenation saturation between upper and lower extremities in patients under spinal anesthesia for orthopedic surgery | Other: tissue oxygen saturation, spinal anesthesia<br>* regional tissue oxygen saturation(rSO2)detected over upper and lower extremities before and after spinal anesthesia<br>* Other names: NIRS model - INVOS(Somanetics) 5100B Cerebral Oximetry;|
| 2Tissue oxygenation change<br>The changes of tissue oxygenation saturation between upper and lower extremities in patients under spinal anesthesia for cesarean section | Other: tissue oxygen saturation, spinal anesthesia<br>* regional tissue oxygen saturation(rSO2)detected over upper and lower extremities before and after spinal anesthesia<br>* Other names: NIRS model - INVOS(Somanetics) 5100B Cerebral Oximetry;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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changes, tissue, oxygenation, saturation, between, upper, lower, extremities, patients, Adverse Effect, Spinal and Epidural