Perioperative effects of continuous insulin infusion during surgery on adult cardiac valve replacement patients

Objective To study the clinic effects of continuous insulin infusion on non-diabetic patients during perioperative period of cardiac valve replacement. Methods Eighty non-diabetic adult patients who underwent elective cardiac valve replacement from November 2010 to November 2012 in Changzheng Hospital were chosen for the study. With the knowledge and consent of the patients and following the signing of the letter of agreement and with the approval of the Ethic Committee,the patients were randomly divided into 2 groups,each consisting of 40 patients. The patients in the treatment group were given continuous insulin infusion. Infusion was performed through cardiopulmonary bypass( CPB) with the micro-pump,and blood glucose was maintained at 6. 1-10. 0 mmol / L. The patients in the control group were intermittently infused with insulin and equal amount of saline,also through CPB and with the micro-pump. If the blood glucose level of patients was higher than 10. 0 mmol / L,intermittent insulin infusion was administered to control the glucose level below 10. 0 mmol / L. Levels of glucose and lactic acid of the patients were monitored at the following different time points: before operation,after anesthesia induction,10 min after obstruction of aorta,10 min after second infilling of the heart arresting fluid,10 min after rewarming,10 min after the opening of aorta,10 min after termination of CPB,and after completion of surgery. Blood glucose levels of patients were monitored at the following time points: the moment after they returned to the intensive care unit( ICU),and at hours 1,2,4,8,16 and 24. Intraoperative automatic cardioversion rate,atrial fibrillation 24h after surgery,rate of hypopotassemia 24 h after surgery,and the length of hospital stay after surgery were recorded accordingly. Results ① For patients in the treatment group,blood glucose levels during surgery were maintained at 6. 1-10. 0mmol / L,which were significantly lower than those of the control( P 0. 05). Peak glucose level of the patients in the treatment group was lower than that of the control group patients during CPB( 7. 85 ± 1. 57) vs( 10. 60 ± 3. 09) mmol / L,with statistical significance( P 0. 05). ② The level of lactic acid in the patients of the treatment group was lower than that of the control group patients,with statistical significance( P 0. 05). ③ Automatic cardioversion rate during surgery for the patients in the treatment group was higher than that of the control group patients( 77. 5% vs 52. 5%), also with statistical significance( P 0. 05). ④ Blood glucose level at hour 24 for the experiment group was lower than that of the control group. Rate of hypopotassemia for the experiment group was lower than that of the control group( 19. 5% vs 37. 5%),with statistical significance( P 0. 05). And the rate of postoperative atrial fibrillation in 24 h for the experiment group was lower that of the control group( 27. 5% vs 52. 5%)( P 0. 05). The length of postoperative hospital stay for the patients in the treatment group was shorter than that of the patients of the control group( 10. 8 ± 2. 4) d vs( 13. 2 ± 3. 2) d,all with statistical significance( P 0. 05). Conclusion For the non-diabetic adult patients who underwent elective cardiac valve replacement,continuous insulin infusion during surgery could maintain blood glucose and potassium level,increase the rate of automatic cardioversion,decrease the rate of postoperative atrial fibrillation in intraoperative and early postoperative periods,and shorten the length of hospital stay after surgery. It was obviously beneficial to the prognosis of patients.