Lung Protection Of Dexmedetomidine In Patients With One Lung Ventilation

Objective:To evaluate the lung protection effect of dexmedetomidine (Dex) in patients who has Esophageal Cancer undergoing one lung ventilation(OLV).Methods:This was a prospective,single-blind,and placebo controlled study. Thirty ASA Ⅱ-Ⅲ patients aged48-75yr,weighting50～78kg underwent esophagectomy were randomly divided into two groups (n=15each):C group (compare group), D group (Dexmedetomidine group).Before anesthsia induction, the group D with using intravenous infusion method was injected1μg/kg dose of DEX for10min,and than was injected at rate of O.5μg·kg-1·h-1until30min before operation. The same volume of normal saline was give in groupC. Anesthesia with Propofol and Remy fentanyl. Central venous blood samples were taken before anesthesia (To), immediately befroe OLV (T1),60min after OLV (T2),120min after OLV (T3),1h after lung inflate (T4),24hours after operation (T5) for the measurements of xanthineoxidase (XOD) and myeloperoxidase (MPO) activity, the count of PMN was performed as well. Measure the concentration of nitric oxide(NO) and vascular endothelial growth factor(VEGF), acquisite arterial and venous blood gas, determine the pulmonary shunt fraction(QS/QT) at T0～T4.Result:Compare with To,The count of PMN was significantly higher at T2～T5(P<0.05), serum XOD and MPO concentration were significantly increase at T2～T5(P<0.05); The of intrapulmonary shunt was significantly higher at T1～-T4(P<0.05);the serum NO and VEGF concentration were significantly crease at T2～T4(P<0.05). compare with Group C, In group D:the counts of PMN were significant decrease at T3～T5(P<0.05). the serum XOD and MPO concentration were significantly decrease at T2～T5(P<0.05); the serum NO concentration were significiantly increase at T3～T4(P<0.05) and the decrease of VEGF at T3～T4(P<0.05).Conclusion:In patients undergoing OLV,continuous infusion of dexmedetomidine intraoperatively has no effect on the intrapulmonary shunt,may protect the lung from improving ischemia-referfusion injury by decreasing the activity of plasma XOD, MPO and by reducing the count of PMN. It also may improve local oxygen supply of the lung by protecting alveolar membrane from injury and reducing the pulmonary capillary permeability.