Evaluation of the Effect of Different Doses Dexmedetomidine Infusion on Lung Mechanics and Oxygenation in Obese Patients

Dexmedetomidine is a selective agonist of α2receptorswhose tendency to α2 receptors is eight times more than that of clonidine. It also has powerful sedative, analgesic, anti-inflammatory, and organ protective properties. dexmedetomidine has favorable respiratory effects in humans. The effects of dexmedetomidine on oxygenation and lung mechanics had been investigated in obstructive lung disease. Dexmedetomidine decreased dead space and improved both lung compliance and oxygenation in chronic obstructive pulmonary disease (COPD) patients undergoing lung cancer surgery. Morbidly obese patients are characterized by the high prevalence of restrictive lung disease.The study include 2 equal groups, each group is 35 patients: Group A(N=35) dexmedetomidine is infused intraoperative after intubation at dose of (1μg/Kg LBW) bolus, followed by 0.5μg/Kg/hour continuous infusion till the end of surgery and Group B(N=35) dexmedetomidine is infused intraoperative after intubation at dose of (0.5μg/Kg LBW) bolus, followed by 0.3μg/Kg/hour continuous infusion till the end of surgery.