Effect of the Height of the Operating Table During Spinal Anesthesia

Study Overview
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Brief Summary
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The purpose of this study is to analyze the accuracy of needle insertion and the discomfort during different ergonomic conditions faced by anesthesiologists during spinal anesthesia. In particular,the investigators intend to compare the angles between the patients' back and the inserted spinal needle in the coronal plane at different operating table heights.

Detailed Description
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Sixty patients will be recruited undergoing elective surgery under spinal anesthesia. The patients will be randomly allocated to one of four groups: Group U, L, X, and N. These acronyms indicate the heights of the operating table which set at the needle insertion point of anesthetists, namely the level of umbilicus, lowest rib margin, xiphoid process, and nipple in a standing posture. The angle between the patient's skin and the spinal needle will be measured by the protractor in the coronal and sagittal plane. The anesthesiologists will be asked to record the subjective general discomfort graded by Numeric Rating Scale. And the degree of neck, lower back, knee, and elbow flexion of the anesthesiologists will be measured by taking pictures during procedure.

Official Title
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Effect of the Height of the Operating Table During Spinal Anesthesia

Conditions
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Anesthesia, Spinal [E03.155.086.331], Operating Tables [E07.325.662]

Intervention / Treatment
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* Procedure: Umbilicus
* Procedure: Lowest rib margin
* Procedure: Xiphoid
* Procedure: Nipple
* Drug: Umbilicus Bupivacaine
* Drug: Lowest rib margin Bupivacaine
* Drug: Xiphoid Bupivacaine
* Drug: Nipple Bupivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: undergoing elective surgery under spinal anesthesia Exclusion Criteria: body mass index (BMI)>30 history of spine operation or severe anatomical abnormalities of spine

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Umbilicus<br>The height of the operating table which set at the needle insertion point, is the level of umbilicus of the anesthesiologist in a standing posture. | Procedure: Umbilicus<br>* Depending on the height of the operating table, the insertion angle of the spinal needles would be vary. The investigators intend to find the optimal angle and the height of the table to provide that. The height of the operating table which set at the needle insertion point of anesthetists; the level of umbilicus<br>Drug: Umbilicus Bupivacaine<br>* If freely flowing of CSF is detected, appropriate dose of MARCAINE was injected in all interventional groups.<br>* Other names: Bupivacaine;|
| Active Comparator: Lowest rib margin<br>The height of the operating table which set at the needle insertion point, is the level of lowest rib margin of the anesthesiologist in a standing posture. | Procedure: Lowest rib margin<br>* The height of the operating table which set at the needle insertion point of anesthetists; the level of lowest rib margin<br>Drug: Lowest rib margin Bupivacaine<br>* If freely flowing of CSF is detected, appropriate dose of MARCAINE was injected in all interventional groups.<br>* Other names: Bupivacaine;|
| Active Comparator: Xiphoid<br>The height of the operating table which set at the needle insertion point, is the level of xiphoid of the anesthesiologist in a standing posture. | Procedure: Xiphoid<br>* The height of the operating table which set at the needle insertion point of anesthetists; the level of xiphoid<br>Drug: Xiphoid Bupivacaine<br>* If freely flowing of CSF is detected, appropriate dose of MARCAINE was injected in all interventional groups.<br>* Other names: Bupivacaine;|
| Active Comparator: Nipple<br>The height of the operating table which set at the needle insertion point, is the level of nipple of the anesthesiologist in a standing posture. | Procedure: Nipple<br>* The height of the operating table which set at the needle insertion point of anesthetists; the level of nipple<br>Drug: Nipple Bupivacaine<br>* If freely flowing of CSF is detected, appropriate dose of MARCAINE was injected in all interventional groups.<br>* Other names: Bupivacaine;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The angle between the patient's skin and the spinal needle |  | during procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| anesthesiologist's subjective discomfort |  | during procedure | 
| the degree of anesthesiologist's joint flexion |  | during procedure |