Effects Of Target-controlled Infusion Of Propofol On Ventricular Repolarization In Patients With Type 2 Diabetes Mellitus

Objective:To observe the effects of target-controlled infusion of propofol on QTc interval,QTcd,Tp-e interval and the ratio of Tp-e/QTc in patients with type 2 diabetes mellitus,and thus to evaluate its effects on ventricular repolarization in patients with type 2 diabetes mellitus.Methods:We enrolled 60 patients,including 30 patients with type 2 diabetes mellitus（PD group）and 30 patients with non-diabetic（P group）.Inclusion criteria:All patients were aged from 35 to 65 years old,American Society of Anesthesiologists（ASA）physical status I～III and body mass index（BMI）18.5～23.9 kg/m².and patients in the PD group were clinically diagnosed as type 2 diabetes mellitus with a history of two years or more and were treated with regular treatment（preoperative fasting blood glucose was controlled in 3.9～10.0 mmol/L）.After arriving in the room,the patient was given electrocardiogram（ECG）monitoring immediately.By adjusting the parameters of the target-controlled infusion pump,The plasma concentration of propofol was set at 4μg/ml.12-lead ECG was collected before target-controlled infusion of propofol（T₁）and after reaching and maintaining the preset concentration of 5 min（T₂）,both the Tp-e interval and QT interval were obtained via the 12-lead ECG,then the QTc interval（the QT interval that was corrected by Bazett’s formula）,the QTcd（difference between the maximum and the minimum of the QTc interval）and the ratio of Tp-e/QTc were calculated.Mean arterial pressure（MAP）,heart rate（HR）,bispectral index（BIS）and the occurrence of arrhythmias during infusion of propofol in two groups were also recorded,and patients who used vasoactive drugs and antiarrhythmic drugs during propofol induction were excluded.Results:We enrolled 30 patients in the PD group while 30 patients in the P group to this research,and no patients was excluded.The fasting blood glucose levels in the PD group were significantly higher than those in the P group（P<0.05）.The MAP,HR and BIS values showed no significant differences between the two groups at T₁and T₂（P>0.05）.but all of them were significantly decreased in both groups after propofol was administered at T₂（P<0.05）.The QTc interval,QTcd,Tp-e interval and the ratio of Tp-e/QTc were signifcantly prolonged at T₁and the QTc interval,QTcd,Tp-e interval were signifcantly prolonged at T₂in the PD group（P<0.05）.The QTc interval and Tp-e interval were signifcantly prolonged in the P group at T₂（P<0.05）,but no significant increase was observed in either the QTcd or the ratio of Tp-e/QTc.No significant differences in QTc interval,QTcd,Tp-e interval and the ratio of Tp-e/QTc was observed as well in the PD group at T₂.and no vasoactive agents as well as anti-arrhythmic drugs was used and no arrhythmias occurred during the study in both groups.Conclusion:Propofol at 4μg/ml plasma target-controlled concentration for anesthetic induction does not further prolong the ventricular repolarization in patients with type 2 diabetes mellitus,and therefore it may not increase the risk of ventricular arrhythmias in patients with type 2 diabetes mellitus.