Effect of dexmedetomidine hydrochloride on coronary blood supply： A clinical study by myocardial contrast echocardiography

Abstract:

Objective：To evaluate the effect of dexmedetomidine hydrochloride on the coronary blood supply of patients through quan－titative analysis of the left ventricular myocardial contrast echocardiography（MCE） results at different time points of continuous instil－lation of dexmedetomidine hydrochloride. Methods：A total of 52 intraoperative patients were randomly divided into experimental group（n=26） and control group（n=26）. The patients in the experimental group received general anesthesia with dexmedetomidine hydrochloride；the MCE images were collected at five different time points：before administration，at 10 min，30 min，and 1 h of administration，at the time of withdrawal，and at 2 h after withdrawal，and then a quantitative analysis was performed on the myocardial acoustic intensity of contrast agent at different time points in a workstation. The control group was given propofol，and the MCE data were collected at the same time points as the experimental group. The myocardial acoustic intensity reflected the blood perfusion in the myocardium；an increase in acoustic intensity difference indicated a reduction in coronary blood perfusion，while a reduction in acoustic intensity difference indicated an increase in coronary blood perfusion. Results：The acoustic intensity difference varied significantly at different time points（P<0.05）. There was a significant interaction between time and group（P<0.05），suggesting the changing trend in acoustic intensity difference over time was different between the experimental group and the control group. The acoustic intensity difference showed no significant difference between the two groups（P=0.268），indicating that the grouping factor had no influence. In the experimental group，the myocardial acoustic intensity difference decreased rapidly from 4.82 to 2.95 at 10 min of administration，and the decrease became slower at 30 min；the acoustic intensity difference returned to the value before administration at 2 h after operation. In the control group，there was no significant change in myocardial acoustic intensity. Conclusion：Dexmedeto－midine hydrochloride can dilate the coronary artery and thus increase the myocardial blood supply during operation.