Predictive Factors for Hypotensive Bradycardic Events During Arthroscopic Shoulder Surgery

Study Overview
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Brief Summary
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Patients's demographics and perioperative factors affect the occurrence of hypotensive bradycardic events in the patients undergoing arthroscopic shoulder surgery in the sitting position under interscalene block.

Detailed Description
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Patients' age, Side of the block,Horner's syndrome, the degree of blockade, preoperative fasting time and fluid administration volume, waiting time for sitting position after the block, intraoperative use of opioids and antihypertensives, and change of heart rate variability before the block and after sitting position affect the occurrence of hypotensive bradycardic events in the patients undergoing arthroscopic shoulder surgery in the sitting position under interscalene block.

Official Title
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Predicting the Occurence of Hypotensive Bradycardic Events in the Patients Undergoing Arthroscopic Shoulder Surgery in the Sitting Position Under Interscalene Brachial Plexus Block

Conditions
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Syncope, Vasovagal

Intervention / Treatment
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* Other: Interscalene brachial plexus block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 15 and 80 years American Society of Anesthesiologists physical status I-II Body mass index < 35 kg/m2 Exclusion Criteria: Coagulation deficiencies Known allergies to local anesthetics Neurologic deficit on the side to be operated Inflammation at the puncture site for interscalene brachial plexus block Coronary artery disease Cardiac conduction disorders and arrhythmias Congestive heart disease Diabetes mellitus Serum electrolyte abnormalities Autonomic dysfunction Psychiatric disorders Patients refusal Communications difficulties Failure of interscalene brachial plexus block

Ages Eligible for Study
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Minimum Age: 15 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Hypotensive bradycardic event<br>The participants are assigned to hypotensive bradycardic event (HBE) group when they experience signs or symptoms associated with syncope, hypotension, or bradycardia, which are treated with vasopressors or inotropics following sitting position after interscalene brachial plexus block is done. Otherwise, they are assigned to non-HBE group. | Other: Interscalene brachial plexus block<br>* After sterile draping around interscalene groove with povidone, a nerve stimulating needle connected to a nerve stimulator is inserted through the interscalene groove. Following involuntary contraction of shoulder, arm, forearm, or hand muscles with 0.5 milliamperes at 1 Hz using the nerve stimulator, 30 to 40 ml of mixture of 1% mepivacaine 20 ml and 0.75% ropivacaine 20 ml are injected.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient's age and gender, fasting time, administered volume, blood pressure, and heart rate variability | Patients'age and gender, preoperative fasting time and volume of fluid administered, pre-block mean arterial pressure and heart rate, logarithmically transformed low frequency, high frequency, and total power of heart rate variability | Prior to ISBPB | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Side of the block, volume of local anesthetics used, number of patients having Horner's syndrome, hoarseness, and subjective dyspnea, degree of dermatomal and motor blockade | Side of the block, volume of local anesthetics used, number of patients having Horner's syndrome (ptosis, miosis, and anhidrosis), hoarseness, and subjective dyspnea, degree of dermatomal blockade (C5, C6, C7, C8, and T1), and degree of motor blockade (median, ulnar, radial, and musculocutaneous nerve) | 20 minutes after the end of local anethetics injection | 
| Waiting time for sitting position, heart rate variability, mean arterial pressure, heart rate, frequency of antihypertensives and opioids use, and onset of hypotensive bradycardic events | Waiting time for sitting position (time from the end of interscalene brachial plexus block to the sitting position), logarithmically transformed high frequency, low frequency, and total power of heart rate variability, mean arterial pressure, heart rate, frequency of intraoperative use of antihypertensives and opioids, and onset of hypotensive bradycardic events | after the sitting position (expected average of 2 hours including surgery readiness time and duration of surgery) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hypotensive bradycardic event, Interscalene brachial plexus block, Sitting position, Shoulder arthroscopic surgery