Senol Gulmen

Does Continuous Insulin Therapy Reduce Postoperative Supraventricular Tachycardia Incidence After Coronary Artery Bypass Operations in Diabetic Patients

OBJECTIVE To compare continuous insulin infusion (CII) and intermittent subcutaneous insulin therapy for preventing supraventricular tachycardia. The authors propose that continuous insulin therapy is more effective to reduce supraventricular tachycardias. DESIGN A prospective randomized study. SETTING This study was performed in 2 different centers between April 2005 and February 2007: Gülhane Military Medical Academy and University of Süleyman Demirel. PARTICIPANTS Two hundred diabetic patients were included in this prospective randomized study. Patients were divided into 2 groups according to their insulin therapy in 2 different centers. INTERVENTIONS Group 1 included 100 diabetes mellitus (DM) patients, and CIIs were administrated. These patients received a CII infusion titrated per protocol in the perioperative period (Portland protocol). Group 2 also included 100 DM patients, and subcutaneous insulin was injected every 4 hours in a directed attempt to maintain blood glucose levels below 200 mg/dL. Sliding scale dosage of insulin was titrated to each patients glycemic response during the prior 4 hours. MEASUREMENTS AND MAIN RESULTS There were 5 hospital mortalities in the intermittent insulin group. The causes of death were pump failure in 3 patients and ventricular fibrillation in 2 patients. There were 2 hospital mortalities in the CII group (p = 0.044). Thirty-six patients in the intermittent insulin group and 21 patients in the CII group required positive inotropic drugs after cardiopulmonary bypass (p = 0.028). Low cardiac output developed in 28 and 16 patients in the intermittent and CII groups, respectively (p = 0.045). Univariate analysis identified positive inotropic drug requirement (p = 0.011, odds ratio [OR] = 3.41), ejection fraction (EF) (p = 0.001, OR = 0.92), cross-clamp time (p = 0.046, OR = 0.97), left internal mammary artery (p = 0.023, OR = 0.49), chronic obstructive pulmonary disease (COPD) (forced expiratory volume in 1 second <75% of predicted value (p = 0.009, OR = 2.02), intra-aortic balloon pump (p = 0.045, OR = 1.23), body mass index (p = 0.035 OR = 5.60), and CII (p < 0.001, OR = 0.36) as predictors of SVT. Stepwise multivariate analysis confirmed the significance of some of the previously mentioned variables as predictors of SVT. The value of -2 log likelihood of multivariate analyses was 421.504. These were EF (p < 0.001, OR = 0.91), positive inotropic drug requirement (p < 0.001, OR = 3.94), COPD (p = 0.036, OR = 2.11), and CII (p < 0.001, OR = 0.19). CONCLUSION Continuous insulin therapy in the perioperative period reduces infectious complications, such as sternal wound infection and mediastinitis, cardiac mortality caused by pump failure, and the risk of development of supraventricular tachycardias.

Tezosentan reduces the renal injury induced by abdominal aortic ischemia-reperfusion in rats.

BACKGROUND Renal injury induced by aortic ischemia-reperfusion (IR) is an important factor in the development of postoperative acute renal failure following abdominal aortic surgery. Endothelin (ET) is involved in the development of renal injury induced by aortic IR and tezosentan (R0 61-0612) is a specific ET receptor antagonist. The aim of this study was to examine the effect of tezosentan on renal injury induced by abdominal aortic IR in rats. MATERIAL AND METHODS Twenty-four Wistar-Albino rats were randomized into three groups (eight per group). Control group underwent laparotomy and dissection of the infrarenal abdominal aorta (IAA) without occlusion. The aortic IR group underwent laparotomy and clamping of the IAA for 120 min followed by 120 min of reperfusion. Aortic IR + tezosentan group underwent same aortic IR periods, and received a bolus intravenous injection of 10 mg/kg tezosentan before ischemia plus continuous intravenous infusion of 1 mg/kg/h tezosentan during 120 min ischemia and 120 min reperfusion. At the end of the experiment, blood and kidney tissue specimens were obtained for biochemical analysis. Histological evaluation of the rat kidney tissues was also done. RESULTS Biochemical analysis showed that aortic IR significantly increased (P < 0.05 versus control) while tezosentan significantly decreased (P < 0.05 versus aortic IR) the tissue levels of malondialdehyde, superoxide dismutase, catalase and myeloperoxidase. Histological analyses showed that aortic IR significantly increased (P < 0.05 versus control) while tezosentan significantly decreased (P < 0.05 versus aortic IR) focal glomerular necrosis, dilatation of Bowmans capsule, degeneration of tubular epithelium, necrosis in tubular epithelium and tubular dilatation in the renal tissue samples. CONCLUSION The results of this study indicate that tezosentan reduces renal injury induced by aortic IR in rats. We think that tezosentan exerted this beneficial effect via reducing oxidative stress and lipid peroxidation, inhibition of leukocyte infiltration into renal tissue and acting cytoprotective on renal tubular cells after aortic IR.

β-Glucan Protects against Lung Injury Induced by Abdominal Aortic Ischemia-Reperfusion in Rats

BACKGROUND Aortic ischemia-reperfusion (IR) is an important factor in the development of postoperative acute lung injury following abdominal aortic surgery. The aim of our study was to examine the effect of β-glucan on lung injury induced by abdominal aortic IR in rats. MATERIAL AND METHODS Thirty-two Wistar-albino rats were randomized into four groups (eight per group) as follows: the control group (sham laparotomy), aortic IR (120 min ischemia and 120 min reperfusion), aortic IR + β-glucan (β-glucan 50 mg/kg/d for 10 d was administered orally before IR), and control + β-glucan. Lung tissue samples were obtained for biochemical analysis. Protein concentrations in bronchoalveolar lavage fluid and lung wet/dry weight ratios were measured. Histologic evaluation of the rat lung tissues was also performed. RESULTS Aortic IR significantly increased the levels of MDA, superoxide dismutase, catalase, and myeloperoxidase (P < 0.05 versus control).Whereas, β-glucan significantly decreased the lung tissue levels of MDA, superoxide dismutase, catalase, myeloperoxidase, (P < 0.05 versus aortic IR), and protein concentration in bronchoalveolar lavage fluid as well as wet/dry lung weight ratio. Histologic evaluation showed that β-glucan attenuated the morphological changes associated with lung injury. CONCLUSIONS The results of this study indicate that β-glucan attenuates lung injury induced by aortic IR in rats. We propose that this protective effect of β-glucan is due to (1) reduced systemic inflammatory response, (2) reduced oxidative stress and lipid peroxidation in the lung tissue, (3) reduced pulmonary microvascular leakage, and (4) inhibition of leukocyte infiltration into the lung tissue.

Ozone therapy as an adjunct to vancomycin enhances bacterial elimination in methicillin resistant Staphylococcus aureus mediastinitis

BACKGROUND We aimed to investigate the influence of intraperitoneal ozone therapy on bacterial elimination and mediastinal inflammation in experimental Staphylococcus aureus mediastinitis. MATERIALS AND METHODS Forty Wistar-Albino rats were randomized into five groups (eight per group) as follows: uncontaminated group, untreated contaminated group, ozone group, vancomycin group, and vancomycin + ozone group. Uncontaminated group underwent upper median sternotomy. The remaining four groups were inoculated with 0.5 mL 10(8) colony-forming units/mL methicillin-resistant Staphylococcus aureus in the mediastinal and sternal layers. Untreated contaminated group had no treatment. Rats in the vancomycin group received intramuscular vancomycin (40 mg/kg/d), and ozone was administered intraperitoneally (70 μg/mL, 1 mg/kg/d) in the ozone group for the treatment of mediastinitis. Vancomycin + ozone group rats were treated by the combination of both methods. At the end of 10 d, quantitative bacterial cultures and sternal tissue samples were obtained for determination of bacterial counts and histologic degree of inflammation. RESULTS Both the vancomycin and the ozone treatments caused significant reduction of bacterial counts in quantitative bacterial cultures. Combination of vancomycin and ozone treatments resulted in further reduction of bacterial counts in mediastinum and sternum. Histologic examination of tissue samples revealed significant reduction in severity of mediastinitis related inflammation in vancomycin and vancomycin + ozone groups compared with untreated contaminated group. CONCLUSIONS Ozone therapy as an adjunct to vancomycin leads to enhanced bacterial elimination in infected sternal and mediastinal tissues in experimental methicillin-resistant Staphylococcus aureus mediastinitis. The benefit of adjuvant ozone therapy is suggested to be related to its bactericidal effect.