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

Background: Restrictive lung disease affects the majority of morbidly obese individuals. This study compared the effects of two different doses of dexmedetomidine (Dex) infusion on oxygenation as primary outcome and on lung mechanics, quality of recovery, and postoperative pain relief as secondary outcomes in morbidly obese patients with restrictive lung disease scheduled for laparoscopic abdominal surgery. Methods: Ninety morbidly obese patients were recruited in this prospective randomized trial. Patients were randomly divided into 3 equal groups. Fifteen minutes after intubation, Dex o.3 and Dex 0.6 groups received a bolus dose of 1μg/kg over 10 min followed by continuous infusion of 0.3 and 0.6 μg/kg/hr for one hour respectively. Control group (C): Patients received comparable volume of normal saline (0.9%).P/F ratio, lung mechanics quality of recovery and perioperative analgesic consumption were recorded. Results: Dex groups resulted in increased P/F ratios, static and dynamic compliance and QoR-15 score compared to control group. Both Dex groups had lower dead space values, lower scores on sedation agitation scale, as well as lower pain scores and perioperative analgesic consumption. However hypotension and bradycardia were more common in the Dex 0.6 groups. Conclusions: Dex infusion at a dose of 0.3µg /kg /hr and 0.6 µg /kg /hr after a loading dose of 1 µg/kg resulted in improvement of oxygenation and lung mechanics lower postoperative pain scores, decreased analgesic consumptions as well as improved quality of recovery in morbidly obese patients with restrictive lung disease undergoing laparoscopic surgery