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

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

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.

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.

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.