Background: Dexmedetomidine is an alpha2 receptor agonist with sedative and analgesic sparing properties. Unlike opioids it is not associated with respiratory depression. Although it is only FDA approved for use as a sedative in the intensive care unit, it has become a popular adjuvant during anesthesia for major surgeries. Among them, laparoscopic bariatric surgery has seen its incidence increase in parallel to the rising number of morbid obese. The use of dexmedetomidine as an adjuvant during laparoscopic bariatric surgery may reduce postoperative opioid requirements and spare the patient of their side effects (nausea, vomiting, respiratory depression, itching…) thereby improving the quality of recovery. These side effects are especially deleterious and to be avoided in morbidly obese patients in which comorbidities are frequent (obstructive sleep apnea, gastroesophageal reflux, hypertension…)
Specific Aim: we aim to compare the effect of dexmedetomidine vs. morphine administered 30 minutes before the anticipated completion of laparoscopic bariatric surgery (sleeve gastrectomy) on patient opioid requirements in the post-anesthesia care unit (PACU) and the quality of recovery.
Methodology: This is a prospective, block randomized double-blind clinical trial. Consenting patients will be divided into two groups. Thirty minutes before the anticipated completion of the surgery, patients will be given either morphine sulfate (bolus 0.08 mg/kg over 10 minutes followed by an infusion of saline) (Group M) or dexmedetomidine (an initial loading dose of 1 µg/kg over 10 minutes followed by 0.5 µg/kg/h) (Group D). Study drug doses will be calculated according to patients’ actual body weight. Postoperatively, patients’ pain will be treated using a patient controlled analgesia machine (PCA) delivering morphine. In the PACU, morphine consumption, numeric rating scale (NRS) for pain and nausea, heart rate, blood pressure, vomiting, retching, itching and sedation score will be compared between the two groups. Quality of recovery scores will be assessed and compared at 24 hours. Overall satisfaction will be collected at one month.
Analysis: morphine consumption in PACU (primary outcome) will be compared between the two groups. Data will be presented as a mean ± SD or numbers and percentages. Statistical analysis will be performed using the Chi-square test, Fisher’s exact test or the Mann-Whitney U-test as appropriate. A P value <0.05 will be considered significant.
the rising prevalence of laparoscopic bariatric surgery combined with the increased
risks and side effects associated with high opioid dosing to treat postoperative
pain, we believe this study will have a high impact on the opioid requirements
and quality of recovery of morbidly obese patients and might change some of the
protocols used for their management.
Morbidly obese inpatients scheduled for bariatric surgeries at AUBMC
Morbidly obese males or females aged between 18 and 60 y with a BMI > 40 kg/m2 or BMI > 35 kg/m2 with comorbid conditions such as hypertension, diabetes or sleep apnea; ASA I or II undergoing laparoscopic sleeve gastrectomy bariatric surgery.
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 and pregnant or breastfeeding.