Effect of Two Different Doses of Dexmedetomidine Infusion in Morbidly Obese Patients

Study Overview
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Brief Summary
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Compare the effects of two different doses of dexmedetomidine infusion on oxygenation as a primary outcome and on lung mechanics, quality of recovery and perioperative analgesia as secondary outcomes in morbidly obese patients with restrictive lung disease undergoing abdominal surgery.

Detailed Description
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Dexmedetomidine is a selective α2 receptor agonist and has sympatholytic, analgesic, anti-inflammatory and sedative properties. Dexmedetomidine decreased dead space and improved both lung compliance and oxygenation in chronic obstructive pulmonary disease (COPD) patients undergoing lung cancer surgery. The effects of dexmedetomidine on oxygenation and lung mechanics had been investigated in obstructive lung disease, but there are little information about its effect in morbidly obese patients with restrictive lung disease .

Official Title
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The Effect of Two Different Doses of Dexmedetomidine Infusion on Oxygenation, Lung Mechanics, and Quality of Recovery in Morbidly Obese Patients: A Prospective Randomized Controlled Study

Conditions
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Anesthesia, Obesity, Morbid, Dexmedetomidine

Intervention / Treatment
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* Drug: Dexmedetomidine 0.6
* Drug: Dexmedetomidine 0.3
* Drug: Saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Body Mass Index above 40 kg/m2 with restrictive lung disease((forced vital capacity) <70% in pre-operative pulmonary function tests), of American Society of anesthesiologists (ASA) physical status II and III. Aged 18-50 years. Scheduled for abdominal surgery. Exclusion Criteria: Patients with Forced expiratory volume1/forced vital capacity<7. Uncontrolled cardiac, respiratory, hepatic or renal diseases. Allergy to the study drug

Ages Eligible for Study
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Minimum Age: 18 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: Dexmedetomidine 0.6 group<br>patients will receive a bolus dose of 1µg/kg dexmedetomidine15 minute after endotracheal intubation over 10 minutes followed by continuous infusion of 0.6 mic/kg/hour for one hour. | Drug: Dexmedetomidine 0.6<br>* Patients received a bolus dose of 1μg/kg Dexmedetomidine, 15 minutes after endotracheal intubation over 10 minutes followed by infusion of 0.6 μg/kg/hr for one hour.<br>|
| Active Comparator: Dexmedetomidine 0.3group<br>patients will receive a bolus dose of 1µg/kg dexmedetomidine 15 minute after endotracheal intubation over 10 minutes followed by continuous infusion of 0.3 mic/kg/hour for one hour. | Drug: Dexmedetomidine 0.3<br>* Patients received a bolus dose of 1μg/kg Dexmedetomidine, 15 minutes after endotracheal intubation over 10 minutes followed by infusion of 0.3 μg/kg/hr for one hour.<br>|
| Placebo Comparator: Control group<br>Patients will receive comparable volume of normal saline (0.9%) 15 minute after endotracheal intubation. | Drug: Saline<br>* Patients received over 10 minutes comparable volume of normal saline (0.9%) 15 min after endotracheal intubation followed by infusion.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intraoperative oxygenation | Intraoperative oxygenation was assessed by P/F ratio (Arterial oxygen tension/fraction of inspired oxygen) at baseline and the end of drug infusion. | Intraoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dynamic Lung compliance | Dynamic lung compliance=tidal volume/ (peak airway pressure- Positive end-expiratory pressure). | Intraoperative | 
| Post-operative pain | Assessment of post-operative pain by The 11-point numeric scale ranges from '0' representing one pain extreme (e.g. no pain) to '10' representing the other pain extreme | 24 hour postoperatively | 
| Dead space (dead space to tidal volume) | Physiological dead space was calculated by Hardman and Aitkenhead equation: (dead space to tidal volume) = 1.14(PaCO2 -EtCO2)/PaCO2- 0.005 dead space (%) = dead space by end of infusion - dead space at the base line / dead space by the end of drug infusion % | Intraoperative | 
| Quality of recovery score | The Quality of recovery score scale provides a score ranging from 0 to 150, with a high score indicating a good quality of recovery | 24 hours Postoperatively | 
| Time to first rescue analgesia | Time to first rescue analgesia as morphine consumption was recorded | 24 hours Postoperatively | 
| Static lung compliance | Static lung compliance =tidal volume /(plateau pressure - Positive end-expiratory pressure). | Intraoperative | 
| Lung compliance | compliance = dynamic compliance at the end of the drug infusion - baseline dynamic compliance. | 24 hours | 
| Plateau pressure | Plateau pressure was calculated by increasing end inspiratory pause to 30-40%. | Intraoperative |