Dexmedetomidine and Desflurane Consumption

Study Overview
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Brief Summary
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The aim of this study is to calculate desflurane consumption when combined with intraoperative dexmedetomidine infusion guided by bispectral index (BIS)

Detailed Description
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Forty patients will be randomly allocated into two equal groups as Group 'D' (Dexmedetomidine group) and Group 'P' (Placebo group) using computer generated random numbers. After arrival in the operating room, ondansetron 0.15 mg/kg intravenous (IV) will be given as a pre-medication. Ringer's acetate solution (500 ml) will be infused as a preload then at a rate of 6-8 ml/kg/h during surgery for supplying maintenance and deficit. Monitoring consisted of continuous electrocardiogram (EKG), non-invasive blood pressure (NIBP), pulse oximetry (SpO2), CO2 expired fraction (ETCO2), desflurane inspired fraction (FIdes), and desflurane expired fraction (ETdes) (Infinity Kappa, Dräger, Lübeck, Germany) will be attached to the patient. BIS module (InfinityR BISxTM SmartPodR, smoothing rate: 15 or 30 seconds, software revision: VF5) will also be attached for detection of consciousness level. All patients will be preoxygenated with 100% oxygen for 3 minutes. The patients in group D will receive dexmedetomidine (2 ml diluted in 18 ml of saline) IV in a dose of 1 mcg/kg over10 minutes through infusion pump prior to induction. Group P patients will receive similar volume of normal saline over 10 min. The study drug and placebo infusions will be prepared by an anesthesiologist who is not involved in the study and the anesthesiologist recording the details is unaware of the type of infusion patients received. Anesthesia will be induced with IV fentanyl 1.5 μg/kg and propofol in a dose of 10 mg every 5 seconds until the BIS level dropped below 60 and confirmed with loss of response to verbal commands. In both groups, Atracurium 0.5 mg/kg IV will be administered, and trachea will be intubated. Fresh gas flow oxygen in air 30-40% at a rate of 3 L/min for 10 minutes will be administered then the flow will be decreased at a rate of 1 L/min using a closed system (Fabius GS, Dräger, Lübeck, Germany) and ventilation will be adjusted to maintain end-tidal carbon dioxide at 30-35 mmHg. Patients in study groups will receive the volatile agent at a concentration of 1 MAC (Minimum Alveolar Concentration). The MAC of desflurane is defined as an expired fraction of 6.0 vol%. Then the dial-up desflurane percentage will be adjusted to establish a BIS value between 40- 50. A maintenance dose of Dexmedetomidine infusion at 0.5 mcg/kg/hour made to 20 mL with normal saline will be administered in group D patients and a similar volume of normal saline will be administered in Group P, till the end of surgery. Top up doses of Atracurium will be given as needed. When heart rate and blood pressure exceeds 20% of baseline in spite of adequate level of anesthesia guided by BIS, boluses of 0.5 μg/kg will be given. While decrease in heart rate and blood pressure more than 20% of baseline, will be treated by ephedrine 5 mg. In both groups, dexmedetomidine or saline will be stopped approximately 15-20 minutes before completion of surgery, diclofenac sodium 1 mg/kg will be given IM at the time of skin closure. Desflurane will be discontinued after skin closure in both groups. Reversal of neuromuscular blockade will be achieved with neostigmine 0.05 mg/kg and atropine 0.02 mg/kg. Tracheal extubation will be done when respiration is satisfactory and adequate muscle tone is achieved

Official Title
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Effect of Dexmedetomidine Infusion on Desflurane Consumption and Hemodynamics During BIS Guided Laparoscopic Surgery: A Randomized Controlled Study

Conditions
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Anesthesia

Intervention / Treatment
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* Drug: Dexmedetomidine
* Drug: Placebo
* Procedure: Ondansetron
* Procedure: fentanyl
* Procedure: propofol
* Procedure: Atracurium
* Procedure: diclofenac sodium
* Procedure: desflurane


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiologists (ASA) status of I and II undergoing elective laparoscopic cholecystectomy Exclusion Criteria: history of psychiatric/neurological illness cardiovascular disease morbid obese patients pregnant and nursing women known allergic reaction to any of the study medication recent use of sedatives or analgesics

Ages Eligible for Study
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Minimum Age: 15 Years
Maximum Age: 50 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
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Group 'D'<br>Dexmedetomidine group Patients received dexmedetomidine (2 ml diluted in 18 ml of saline) IV in a dose of 1 mcg/kg over 10 minutes. A maintenance dose of Dexmedetomidine infusion at 0.5 mcg/kg/hour was infused. Ondansetron: 0.15 mg/kg intravenous preoperative. Fentanyl: 1.5 μg/kg intraoperative Propofol: 10 mg every 5 seconds until the BIS level dropped below 60 for induction of anesthesia. Atracurium: 0.5 mg/kg IV. Desflurane: 1 MAC concentration. Diclofenac sodium: 1 mg/kg for postoperative analgesia. | Drug: Dexmedetomidine<br>* A maintenance dose of Dexmedetomidine infusion at 0.5 mcg/kg/hour made to 20 mL with normal saline will be administered<br>* Other names: Dexdor;Procedure: Ondansetron<br>* 0.15 mg/kg intravenous (IV) will be given as a pre-medication<br>* Other names: Zofran;Procedure: fentanyl<br>* 1.5 μg/kg intraoperative<br>* Other names: Sublimaze,Actiq, Durogesic, Duragesic;Procedure: propofol<br>* 10 mg every 5 seconds until the BIS level dropped below 60 for induction of anesthesia<br>* Other names: Diprivan;Procedure: Atracurium<br>* 0.5 mg/kg IV for endotracheal intubation<br>* Other names: Atracurium besilate;Procedure: diclofenac sodium<br>* 1 mg/kg for postoperative analgesia<br>* Other names: Voltaren;Procedure: desflurane<br>* 1 MAC concentration (expired fraction of 6.0 vol%) for maintenance of anesthesia<br>* Other names: Suprane;|
| Placebo Comparator: Group 'P'<br>Placebo group Patients received similar volume of normal saline as the bolus and maintenance infusion as group D. Ondansetron: 0.15 mg/kg intravenous preoperative. Fentanyl: 1.5 μg/kg intraoperative Propofol: 10 mg every 5 seconds until the BIS level dropped below 60 for induction of anesthesia. Atracurium: 0.5 mg/kg IV. Desflurane: 1 MAC concentration. Diclofenac sodium: 1 mg/kg for postoperative analgesia. | Drug: Placebo<br>* A maintenance dose of 20 mL with normal saline will be administered at a rate similar to that of dexmedetomidine<br>* Other names: placebo effect;Procedure: Ondansetron<br>* 0.15 mg/kg intravenous (IV) will be given as a pre-medication<br>* Other names: Zofran;Procedure: fentanyl<br>* 1.5 μg/kg intraoperative<br>* Other names: Sublimaze,Actiq, Durogesic, Duragesic;Procedure: propofol<br>* 10 mg every 5 seconds until the BIS level dropped below 60 for induction of anesthesia<br>* Other names: Diprivan;Procedure: Atracurium<br>* 0.5 mg/kg IV for endotracheal intubation<br>* Other names: Atracurium besilate;Procedure: diclofenac sodium<br>* 1 mg/kg for postoperative analgesia<br>* Other names: Voltaren;Procedure: desflurane<br>* 1 MAC concentration (expired fraction of 6.0 vol%) for maintenance of anesthesia<br>* Other names: Suprane;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| desflurane consumption (ml) | Calculation of desflurane consumption during the intraoperative period | Intraoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart Rate (Beat/min) | Recording of the heart rate during the intraoperative period before induction, after induction, after intubation, and then at 5, 10, 15, 30, 45, and 60 minute after intubation and at extubation. | Intraoperative | 
| Blood Pressure (mm Hg) | Recording of the heart rate during the intraoperative period before induction, after induction, after intubation, and then at 5, 10, 15, 30, 45, and 60 minute after intubation and at extubation. | Intraoperative | 
| Fentanyl consumption (ug) | Total intraoperative fentanyl consumption | Intraoperative | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dexmedetomidine, Desflurane, Bispectral Index BIS