Dexmedetomidine for Postoperative Analgesia After Bariatric Surgery

Inclusion Criteria: * Body Mass Index \> 40 kg/m2 or BMI \> 35 kg/m2 with comorbid conditions such as hypertension, diabetes or sleep apnea * American Society of Anesthesiologists class I or II * Undergoing laparoscopic sleeve gastrectomy bariatric surgery Exclusion Criteria: * Allergy to morphine or its derivatives * Allergy to α-2 adrenergic agonists * weight over 180 kg * history of uncontrolled hypertension * heart block greater than first degree * prolonged QT interval * clinically significant neurologic, cardiovascular, renal, hepatic, or gastrointestinal diseases * received an opioid analgesic medication within a 24 h period prior to surgery * history of alcohol, drug abuse or chronic opioid intake * history of psychiatric disorder * pregnant or breastfeeding.