Effect of Atropine or Glycopyrrolate on the Prevention of Bradycardia During Sedation Using Dexmedetomidine in Adult Patients Undergoing Lower Extremity Surgery Under Spinal Anesthesia

Study Overview
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Brief Summary
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Patients undergoing lower extremity surgery with spinal anesthesia are often sedated to reduce patient discomfort due to large noises during surgery and also to reduce anxiety. Most commonly used sedatives include propofol and midazolam, but these agents are known to often cause hypotension or respiratory depression. Dexmedetomidine is a selective alpha 2 adrenergic drug, which acts as a sedative and also has analgesia effects. In contrast to propofol or midazolam, dexmedetomidine rarely causes respiratory depression, and therefore is often used in critically ill patients in the ICU and also in patients undergoing simple procedures. Hemodynamically, dexmedetomidine evokes a biphasic blood pressure response with a short hypertensive phase and subsequent hypotension. Bradycardia is also observed in many patients, which may lead to more serious outcomes when progressing to sinus pause or shock. Therefore, drugs to prevent bradycardia during dexmedetomidine infusion may help patients maintain a more stable hemodynamic state. The present study aims to compare the ability of atropine and glycopyrrolate to prevent bradycardia during dexmedetomidine infusion in patients undergoing lower extremity orthopedic surgery with spinal anesthesia.

Official Title
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Effect of Atropine or Glycopyrrolate on the Prevention of Bradycardia During Sedation Using Dexmedetomidine in Adult Patients Undergoing Lower Extremity Surgery Under Spinal Anesthesia

Conditions
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Spinal Anesthesia

Intervention / Treatment
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* Drug: Atropine
* Drug: Glycopyrrolate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients 65 years or older undergoing total knee replacement surgery under spinal anesthesia. ASA class 1-3 Exclusion Criteria: Patients with coagulation abnormalities End organ diseases of liver, lung or kidney Severe aortic stenosis High degree AV block Heart failure Patients on MAO inhibitors History of seizures or epilepsy Glaucoma

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 60 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Atropine group<br>Patients that receive atropine 0.01 mg/kg (max 0.5mg) before spinal anesthesia | Drug: Atropine<br>* Atropine injection (0.01 mg/kg, max 0.5 mg) 3 minutes before spinal anesthesia<br>|
| Active Comparator: Glycopyrrolate group<br>Patients that receive glycopyrrolate 0.004mg/kg (max 0.2 mg) before spinal anesthesia | Drug: Glycopyrrolate<br>* Glycopyrrolate (0.00 4mg/kg, max 0.2 mg) 3 minutes before spinal anesthesia<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pulse rate | measured as beats per minute, heart rate below 60 bpm or decrease of more than 30% from baseline is defined as bradycardia. | From 5 minutes before spinal anesthesia end of surgery (Intraoperatively) | 
| blood pressure | measured as mmHg, mean blood pressure lower than 60 mmHg or decrease of more than 30% from baseline is defined as hypotension. | From 5 minutes before spinal anesthesia end of surgery (Intraoperatively) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Atropine, glycopyrrolate, bradycardia, dexmedetomidine, spinal anesthesia