Aminophylline on Perioperative Lung Mechanics in COPD Morbidly Obese Patients Undergoing Laparoscopic Bariatric Surgery

Study Overview
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Brief Summary
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The aim of this study is to evaluate the usefulness of adding aminophylline to dexmedetomidine intravenous infusion intraoperatively on oxygenation and lung mechanics in chronic obstructive pulmonary disease (COPD) morbidly obese patients undergoing bariatric surgery.

Detailed Description
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Bariatric surgery is considered the most effective treatment for patients suffering from morbid obesity, as it results in maintained loss of weight and clear impact on the comorbidities related to obesity. However, despite the advantages of anesthesia, it can have detrimental effects on the recovery of obese patients who have a high prevalence of respiratory conditions and sleep disorders. Obesity is usually related to other respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD). According to a meta-analysis encompassing more than 300,000 adult patients, obesity and asthma were interlinked, and as BMI increased, a higher risk of asthma was noticed. The use of dexmedetomidine infusion in morbid obese patients was assessed by many clinical trials. They revealed that the use of dexmedetomidine has the same analgesic effect as the use of fentanyl with greater hemodynamic stability obtained with the use of dexmedetomidine. Dexmedetomidine has the advantage of having no respiratory depressant effect. Also, it has an amnestic effect. Dexmedetomidine does not affect the sleep pattern and maintains the airway patency. Aminophylline is a compound of theophylline with ethylenediamine and most common uses in the airway obstruction such as asthma and COPD. primarily for its bronchodilating and central nervous stimulating effects. However, emprical evidence suggests that aminophylline, as an adenosine antagonist, can improve the recovery time from general anesthesia.

Official Title
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Impacts of Aminophylline on Perioperative Lung Mechanics in COPD Morbidly Obese Patients Undergoing Laparoscopic Bariatric Surgery: A Prospective Randomized Double Blinded Trial

Conditions
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Aminophylline, Chronic Obstructive Pulmonary Disease, Laparoscopic Bariatric Surgery, Dexmedetomidine, Lung Mechanics, Obese

Intervention / Treatment
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* Drug: Aminophylline-Dexmedetomidine
* Drug: Dexmedetomidine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age from 20 to 60 years. Patients scheduled for laparoscopic bariatric surgery not exceeding three hours under general anesthesia. American Society of Anesthesiologists (ASA) class II to III. Patients who had no previous abdominal surgery. Patients with a body mass index (BMI) greater than 40 kg/m2and suffered obstructive lung disease diagnosed by pulmonary function tests (; forced vital capacity (FEV1\FVC) < 70%). Patients who are psychologically normal. Exclusion Criteria: Patients who refuse to participate. Those with arrhythmia or receiving anti-arrhythmic medications. Those with significant coexisting diseases (e.g. kidney, heart, liver). Those with known allergy to any of allocated drugs. Those with excessive intraoperative blood loss more than allowable amount to every patient.

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 |
| --- | --- |
| Experimental: Aminophylline-Dexmedetomidine Group<br>10 minutes after endotracheal intubation, patients will receive IV bolus of dexmedetomidine 0.5 microgm/kg Lean body weight (LBW) over 15 min, followed immediately by intravenous infusion at 0.2 microgm /kg LBW/h and IV bolus of aminophylline of 5 mg/kg based on the ideal body weight (IBW) over 30 min, followed immediately by intravenous infusion at 0.6 mg/kg IBW/h. The study solutions will be diluted in 50 ml normal saline. | Drug: Aminophylline-Dexmedetomidine<br>* 10 minutes after endotracheal intubation, patients will receive intravenous (IV) bolus of dexmedetomidine 0.5 microgm/kg Lean body weight (LBW) over 15 min, followed immediately by intravenous infusion at 0.2 microgm /kg LBW/h and IV bolus of aminophylline of 5 mg/kg based on the ideal body weight (IBW) over 30 min, followed immediately by intravenous infusion at 0.6 mg/kg IBW/h. The study solutions will be diluted in 50 ml normal saline.<br>|
| Active Comparator: Dexmedetomidine<br>10 minutes after endotracheal intubation, patients will receive IV bolus of dexmedetomidine 0.5 microgm/kg LBW over 15 min, followed immediately by intravenous infusion at 0.2 microgm /kg LBW/h. The study solutions will be diluted in 50 ml normal saline. | Drug: Dexmedetomidine<br>* 10 minutes after endotracheal intubation, patients will receive intravenous (IV) bolus of dexmedetomidine 0.5 microgm/kg Lean body weight (LBW) over 15 min, followed immediately by intravenous infusion at 0.2 microgm /kg LBW/h. The study solutions will be diluted in 50 ml normal saline.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Static lung compliance | Static lung compliance will be calculated as: tidal volume/ [plateau pressure - Positive end-expiratory pressure (PEEP)] at 5 minutes after endotracheal intubation (baseline), 30 and 90 minutes after the beginning of the drug infusion. | Up to 90 minutes after the beginning of the drug infusion. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dynamic lung compliance | Dynamic lung compliance will be calculated as: tidal volume/ [peak airway pressure - Positive end-expiratory pressure (PEEP)] at 5 minutes after endotracheal intubation (baseline), 30 and 90 minutes after the beginning of the drug infusion. | Up to 90 minutes after the beginning of the drug infusion. | 
| Intraoperative oxygenation | Intraoperative oxygenation will be measured at 5 minutes after endotracheal intubation (baseline), 30 and 90 minutes after the beginning of the drug infusion determined by (S/F ratio: SPO2/ FiO2). | Up to 90 minutes after the beginning of the drug infusion. |