Effects of Continuous Dexmedetomidine Infusion on Systemic Microvascular Function in Laparoscopic Cholecystecthomy

Study Overview
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Brief Summary
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The microcirculation represents the primary site of exchange of oxygen and nutrients for tissues, and the preservation of microcirculatory perfusion is essential for the maintenance of organ function. The microcirculation is extremely dynamic and may vary according to the individual's temperature, systemic blood pressure, the use of medications, during physical and mental activity, age and pathological processes. In this context, the development of portable microscopes for clinical use has made possible the non-invasive visualization of the microcirculation and tissue perfusion in patients undergoing several highly complex procedures in cardiology, including cardiac surgery with cardiopulmonary bypass, ECMO (Extracorporeal Membrane Oxygenation) and in critically ill patients in intensive care. CytoCam, for example, is a handheld device that incorporates a darkfield incident light illumination system with a series of high-resolution lenses that project images to a computer dedicated to the system. Dexmedetomidine is a selective agonist of 2-adrenergic receptors in the central nervous system, whose administration results in a reduction in the activity of the sympathetic nervous system and a reduction in the systemic release of catecholamines. Its use in the perioperative period has several beneficial effects, such as reducing neuroendocrine and hemodynamic responses due to anesthesia and surgery, through induction of sedation and analgesia, in addition to reducing the consumption of opioids and anesthetics in general. Several recent studies report that the use of dexmedetomidine in the perioperative period reduces the incidence of postoperative complications, reduces the time on mechanical ventilation and attenuates the neuroendocrine response due to surgical trauma and extracorporeal circulation in patients undergoing cardiac surgery. However, the effects of dexmedetomidine on systemic microcirculation function during its use in anesthesia for elective surgical procedures of medium complexity are not yet known. In conclusion, the hypothesis of the present study is that continuous intravenous infusion of dexmedetomidine during balanced general anesthesia increases the microvascular perfusion flow rate in the sublingual mucosa, representing an increase in systemic microvascular perfusion.

Detailed Description
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CytoCam, is a handheld device that incorporates a darkfield incident light illumination system with a series of high-resolution lenses that project images to a computer dedicated to the system. Dexmedetomidine is a selective agonist of 2-adrenergic receptors in the central nervous system, whose administration results in a reduction in the activity of the sympathetic nervous system and a reduction in the systemic release of catecholamines. Its use in the perioperative period has several beneficial effects, such as reducing neuroendocrine and hemodynamic responses due to anesthesia and surgery, through induction of sedation and analgesia, in addition to reducing the consumption of opioids and anesthetics in general. Several recent studies report that the use of dexmedetomidine in the perioperative period reduces the incidence of postoperative complications, reduces the time on mechanical ventilation and attenuates the neuroendocrine response due to surgical trauma and extracorporeal circulation in patients undergoing cardiac surgery. However, the effects of dexmedetomidine on systemic microcirculation function during its use in anesthesia for elective surgical procedures of medium complexity are not yet known. In conclusion, the hypothesis of the present study is that continuous intravenous infusion of dexmedetomidine during balanced general anesthesia increases the microvascular perfusion flow rate in the sublingual mucosa, representing an increase in systemic microvascular perfusion.

Official Title
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Evaluation of the Effects of Continuous Dexmedetomidine Infusion on Systemic Microvascular Function in Patients Undergoing Laparoscopic Cholecystecthomy: a Prospective Study

Conditions
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Laparoscopic Surgery

Intervention / Treatment
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* Drug: dexmedetomidine intravenous infusion
* Drug: 0.9%sodium chloride


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients of both sexes (age ≥ 18 and ≤ 60 years) Physical state ASA I or II according to the criteria of the American Association of Anesthesiology Planned surgery of cholecystectomy by videolaparoscopy Exclusion Criteria: Patient's refusal to participate in the study Inflammation or infection in the sublingual mucosa Emergency surgery Grade III obesity (BMI ≥39.9 kg/m2) Pregnancy or lactation Autoimmune diseases, malignant neoplasms

Ages Eligible for Study
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Minimum Age: 18 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Patients will be randomized into two groups of 35 patients each: 1) patients who will receive continuous intraoperative infusion of dexmedetomidine hydrochloride (0.5 µg/kg/h) (DEX group) or 2) control group, patients who will receive continuous infusion of 0.9% saline solution (CONT group).
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: dexmedetomidine intravenous infusion<br>Patients who will receive continuous intraoperative infusion of dexmedetomidine hydrochloride (0.5 µg/kg/h). | Drug: dexmedetomidine intravenous infusion<br>* Dexmedetomidine intravenous infusion during laparoscopic cholecystecthomy<br>|
| Sham Comparator: 0.9% saline solution intravenous infusion<br>Patients who will receive continuous infusion of 0.9% saline solution (sham group). | Drug: 0.9%sodium chloride<br>* 0.9%sodium chloride intravenous infusion during laparoscopic cholecystecthomy<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in microvascular flow index | sublingual microvascular density | during surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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microcirculation, general anesthesia, central alpha-2 agonists, tissue perfusion, dexmedetomidine