Effects of Dexmedetomidine on Renal Function of Patients after Valvular Heart Surgery / 实用医学杂志

Objective To investigate the effect of dexmedetomidine on postoperative renal function of patients with rheumatic heart disease following valvular heart surgery. Methods Fifty patients following valvular heart surgery were randomized into experimental group and control group,with 25 cases in each group. The patients in experimental group receiveddexmedetomidine 0.5 μg/kg infusion 15min before induction, and then 0.5 μg/(kg·h) infused to the end of surgery, while those in control group received the same amount of saline in the same way. Blood from central venous was collected before surgery, at the end of surgery, 24 h and 48 h after surgery in order to detect Src, BUN and Cys C and the length of ICU duration was also recorded. Results Src and Cys C of the patients in both groups obviously elevated 24h after surgery when compared with pre-operation , while BUN elevated at both 24 h and 48 h after surgery(P < 0.05). Compared with those in control group, Src, BUN and Cys C were lower in experimental group ( P < 0 . 05 ) , and the length of ICU duration was shorter (P < 0.05). Conclusion Dexmedetomidine could improve the postoperative renal function after valvular heart surgery and lead to a better prognosis.

Efficacy of Goal-Directed Therapy Using Bioreactance Cardiac Output Monitoring after Valvular Heart Surgery

PURPOSE: We compared the efficacy of postoperative hemodynamic goal-directed therapy (GDT) using a pulmonary artery catheter (PAC) and bioreactance-based noninvasive cardiac output monitoring (NICOM) in patients with atrial fibrillation undergoing valvular heart surgery. MATERIALS AND METHODS: Fifty eight patients were randomized into two groups of GDT with common goals to maintain a mean arterial pressure of 60-80 mm Hg and cardiac index > or =2 L/min/m2: the PAC group (n=29), based on pulmonary capillary wedge pressure, and the NICOM group (n=29), based on changes in stroke volume index after passive leg raising. The primary efficacy variable was length of hospital stay. Secondary efficacy variables included resource utilization including vasopressor and inotropic requirement, fluid balance, and major morbidity endpoints. RESULTS: Patient characteristics and operative data were similar between the groups, except that significantly more patients underwent double valve replacement in the NICOM group. The lengths of hospital stay were not different between the two groups (12.2+/-4.8 days vs. 10.8+/-4.0 days, p=0.239). Numbers of patients requiring epinephrine (5 vs. 0, p=0.019) and ventilator care >24 h (6 vs. 1, p=0.044) were significantly higher in the PAC group. The PAC group also required significantly larger amounts of colloid (1652+/-519 mL vs. 11430+/-463 mL, p=0.004). CONCLUSION: NICOM-based postoperative hemodynamic GDT showed promising results in patients with atrial fibrillation undergoing valvular heart surgery in terms of resource utilization.

Value of neutiophil gelatinase-associated lipocalin in early diagnosis of acute kidney injury following adult valvular heart surgery / 安徽医科大学学报

Objective To explore the value of neutiophil gelatinase-associated lipocalin ( NGAL) taken from blood and urine samples in early diagnosis of acute kidney injury ( AKI) after heart valves replacement surgeries. Meth-ods A total of 56 patients received heart valves replacement surgeries were selected prospectively in this study. NGAL from blood and urine samples and serum creatinine ( Scr) were tested among them at different moments. AKI and non-AKI groups were divided based on Scr levels and the value of NGAL taken from blood and urine sam-ples was estimated in early diagnosis of AKI with receiver operating characteristic curve ( ROC) . Results 16 AKIs were observed among all of them. The peak value of Scr in AKI group was shown between 12 and 24 hours after surgeries, while blood-NGAL was seen high significantly (P<0.05) since 2 hours after surgeries, peak value at 4 hours, for urine-NGAL, peak value was seen at 2 hours. The area of ROC of blood-NGAL 4 hours and urine-NGAL 2 hours after surgeries for AKI diagnosis were 0.891 and 0.934, respectively. The better sensitivity and specificity were shown in both threshold set as 50 μg/L and 110 μg/L. Conclusion Blood-NGAL and urine-NGAL can be used as early diagnostic markers of AKI after heart valves replacement surgeries, whose change is significantly earli-er than that of Scr.

Effect of arterial oxygen tension during reperfusion on myocardial recovery in patients undergoing valvular heart surgery / 대한마취과학회지

BACKGROUND: Valvular heart surgery (VHS) utilizing cardiopulmonary bypass (CPB) is inevitably associated with ischemic-reperfusion injury, which is known to depend on oxygen tension during reperfusion. The aim of this study was to evaluate the effect of arterial oxygen tension during reperfusion on myocardial recovery in patients undergoing VHS. METHODS: Fifty-six patients undergoing isolated VHS were randomly exposed to an oxygen fraction of 0.7 (hyperoxic group, n = 28) or 0.5 (normoxic group, n = 28) during reperfusion. All patients received an oxygen fraction of 0.7 during CPB. In the normoxic group, the oxygen fraction was lowered to 0.5 from the last warm cardioplegia administration to 1 minute after aortic unclamping, and was then raised back to 0.7. Hemodynamic data were measured after induction of anesthesia, weaning from CPB, and sternum closure. The frequency of cardiotonic medications used during and after weaning from CPB, and the short-term outcomes during the hospital stay were also assessed. RESULTS: The frequency of vasopressin and milrinone use during weaning from CPB, but not norepinephrine, was significantly less in the normoxic group. The post-operative cardiac enzyme levels and short-term outcomes were not different between the groups. CONCLUSIONS: Normoxic reperfusion from the last cardioplegia administration to 1 minute after aortic unclamping in patients undergoing VHS resulted in significantly less frequent use of vasopressin and inotropics during weaning from CPB than hyperoxic reperfusion, although it did not affect the post-operative myocardial enzyme release or short-term prognosis.

Cardiovascular effects of oral tri-iodothyronine in patients undergoing valvular cardiac surgery / 대한마취과학회지

BACKGROUND: Cardiopulmonary bypass produces a state of functional hypothyroidism characterized by low levels of circulating tri-iodothyronine (T3). Theoretically, supplementing T3 should result in improved hemodynamics as well as patients' outcome. The aim of the present study was to determine whether pretreatment with single oral T3 could prevent serum T3 reduction, and improve hemodynamics and clinical outcome. METHODS: Forty-seven patients undergoing valvular heart surgery were included in the study. Patients were randomly assigned into two groups (T = T group; C = control group) the day before surgery and received single oral T3 40 microg or placebo before operation. Blood samples were collected for determination of serum levels of total T3, T4 and TSH before administration of oral T3 or placebo (baseline), 1, 6 and 18 hour after weaning of cardiopulmonary bypass. Hemodynamic parameters and medication were recorded during the intraoperative period and throughout the first 24 h after arrival at the intensive care unit. RESULTS: T3 levels were significantly higher in the T group 1 hr after weaning of cardiopulmonary bypass. T3 levels in the T group were all maintained within the normal range throughout the study period, whereas it was decreased to below normal level in the C group at 18 hr after weaning of cardiopulmonary bypass. In the T group, vasoactive agent requirements were reduced during and after cardiopulmonary bypass. CONCLUSIONS: Pretreatment with single oral T3 prevented the reduction in T3 level after valvular heart surgery, with subsequent reduction in vasoactive agent requirement.