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Perfusion Time (perfusion + time)
Selected AbstractsPredictors and Outcomes Associated with Intraoperative Aortic Dissection in Cardiac SurgeryJOURNAL OF CARDIAC SURGERY, Issue 5 2008Amber Hurt M.D. The objective of this study was to assess risk factors of aortic dissection and assess outcomes in patients with aortic dissection experience. Methods: A study from a 10-year hospitalization cohort (N = 12,907) with prospective data collection was conducted. Patients without aortic dissection were matched to 33 aortic dissection patients 3:1 on the type of procedure. The study examined 24 potential confounding risk factors and 12 outcome variables. Results: Univariate analysis on potential confounding risk factors revealed two significant risk factors. There was a significant difference between aortic dissection and nonaortic dissection patients with New York Heart Association (NYHA) functional class (p = 0.03). Patients with aortic dissection were more likely to be in Class I or II. Patients with aortic dissection had significantly longer perfusion time (p = 0.008). There was a significant difference between patients with and without aortic dissection on four outcome variables. Patients with an aortic dissection were more likely to need prolonged ventilation (p = 0.046), have renal failure (p = 0.005), require intraaortic balloon pump (IABP) (0.043), and have a higher mortality rate (p < 0.001). Conclusion: Aortic dissection occurs infrequently during coronary artery bypass grafting, but is a devastating complication and greatly increases morbidity. Although few patients dissect intraoperatively, this study attempted to identify predictors that may label a patient as high risk for possible aortic dissection. Although two factors in this study were statistically significant, they are not reliable preoperative predictors of high-risk patients that can be used to screen patients and help prevent aortic dissection and its sequela. [source] Risk Factors for Requirement of Permanent Pacemaker Implantation After Aortic Valve ReplacementJOURNAL OF CARDIAC SURGERY, Issue 3 2006Hasan Basri Erdogan M.D. Methods: Among 465 patients operated between 1994 and 2004, 19(4.1%) patients with a mean age 49.9 ± 17.2 years required the implantation of a permanent pacemaker. Eleven of them were female (57.9%). The main indication was aortic stenosis (89.5%). Severe annular calcification was documented in 78.9% of them, and the aortic valve was bicuspid in 57.9%. Results: Risk factors for permanent pacing after aortic valve replacement (AVR) identified by univariate analysis were female sex, hypertension, preoperative ejection fraction, aortic stenosis, annular calcification, bicuspid aorta, presence of right bundle branch block (RBBB) or left bundle branch block (LBBB), prolonged aortic cross-clamp and perfusion times, and preoperative use of calcium channel blockers. Multivariate analysis showed that female sex (p = 0.01, OR; 5.21, 95% CI: 1.48-18.34), annular calcification (p < 0.001, OR; 0.05, 95% CI: 0.01-0.24), bicuspid aortic valve (p = 0.02, OR; 0.24, 95% CI: 0.07-0.84), presence of RBBB (p = 0.009, OR; 0.03, 95% CI: 0.003-0.44) or LBBB (p = 0.01, OR; 0.13, 95% CI: 0.02-0.69), hypertension (p = 0.03, OR; 0.22, 95%CI: 0.05-0.89), and total perfusion time (p = 0.002, OR; 1.05, 95% CI: 1.01-1.08) were associated risk factors. Conclusion: Irreversible atrioventricular block requiring a permanent pacemaker implantation is an uncommon complication after AVR. Risk factors are annular calcification, bicuspid aorta, female sex, presence of RBBB or LBBB, prolonged total perfusion time, and hypertension. [source] Mini-Maze Suffices as Adjunct to Mitral Valve Surgery in Patients with Preoperative Atrial FibrillationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2000ANTON E. TUINENBURG M.D. Mini-Maze and Mitral Valve Surgery. Introduction: After mitral valve (MV) surgery, preoperative atrial fibrillation (AF) often recurs while cardioversion therapy generally fails. Additional Cox maze surgery improves postoperative arrhythmia outcome, but the extensive nature of such an approach limits general appliance. We investigated the clinical outcome of a simplified, less extensive Cox maze procedure ("mini-maze") as adjunct to MV surgery. Methods and Results: Thirteen patients with MV disease and preoperative AF were treated with combined surgery (group 1). Nine control patients without previous AF underwent isolated MV surgery (group 2). We retrospectively compared the results to findings in 23 patients with preoperative AF who had undergone isolated MV surgery (group 3). In group 1, mini-maze took an additional 46 minutes of perfusion time. One 75-year-old patient died of postoperative multiple organ failure. Seven patients showed spontaneously converting (within 2 months) postoperative AF. After 1 year, 82% were in sinus rhythm (SR). No sinus node dysfunction was observed. In group 2, all patients were in SR after 1 year. In group 3, only 53% were in SR after 1 year, despite serial cardioversion and antiarrhythmic drug therapy. Exercise tolerance and heart rate were comparable for groups 1 and 2. Left atrial function was present in all but one patient in group 1 and in all patients in group 2 (after MV reconstruction). Conclusion: Adding a relatively simple mini-maze to MV surgery improves arrhythmia outcome in patients with preoperative AF without introducing sinus node dysfunction or persistent absence of left atrial function. The results of this type of combined surgery are encouraging and deserve further attention. [source] Biliary inorganic phosphate as a tool for assessing cold preservation-reperfusion injury: A study in the isolated perfused rat liver modelLIVER TRANSPLANTATION, Issue 2 2003Luciana L. Almada Ischemia-reperfusion injury is a major cause of early graft dysfunction after liver transplantation. The bile flow has been suggested as an index of ischemic damage, and severely impaired bile flow seems to be predictive of poor survival in experimental studies. Looking for injury markers, biliary inorganic phosphate has the potential of being a useful endogenous marker of diminished hepatobiliary function because this anion is excreted in the bile by a paracellular pathway and it can detect changes in permeability. The goal of this study was to evaluate the effects of cold preservation-reperfusion of the liver on bile flow and bile inorganic phosphate and their relationship with storage-related graft failure. The isolated and perfused rat liver was used to evaluate the injury for ischemia-reperfusion. The intrahepatic resistance, lactate dehydrogenase release, and potassium and biliary inorganic phosphate concentration were used to estimate viability and function of freshly isolated or cold-preserved livers. The intrahepatic resistance and the bile flow were consistent and significantly decreased throughout the perfusion time in relation to the increment in storage. Inorganic phosphate is more concentrated in bile from preserved livers, showing an alteration in paracellular pathway, confirmed by the biliary excretion of horseradish peroxidase. After preservation, concentration and excretion of the paracellular marker were increased during the first peak. The second peak appears earlier in preserved livers (10 minutes) with a different shape but without changes in concentration. In conclusion, inorganic phosphate in bile shows changes in paracellular permeability as occurs in livers after 48 hours of cold preservation. [source] Validation of a differential in situ perfusion method with mesenteric blood sampling in rats for intestinal drug interaction profilingBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 5-6 2010Joachim Brouwers Abstract The present study explored the feasibility of a differential setup for the in situ perfusion technique with mesenteric cannulation in rats to assess drug interactions at the level of intestinal absorption. In contrast to the classic, parallel in situ perfusion setup, the differential approach aims to identify intestinal drug interactions in individual animals by exposing the perfused segment to a sequence of multiple conditions. First, the setup was validated by assessing the interaction between the P-glycoprotein (P-gp) inhibitor verapamil and the transport probes atenolol (paracellular transport), propranolol (transcellular) and talinolol (P-gp mediated efflux). While transport of atenolol and propranolol remained constant for the total perfusion time (2,h), a verapamil-induced increase in talinolol transport was observed within individual rats (between 3.2- and 5.2-fold). In comparison with the parallel setup, the differential in situ perfusion approach enhances the power to detect drug interactions with compounds that exhibit strong subject-dependent permeability. This was demonstrated by identifying an interaction between amprenavir and ketoconazole (P-gp and CYP3A inhibitor) in five out of seven rats (permeability increase between 1.9- and 4.2-fold), despite high inter-individual differences in intrinsic permeability for amprenavir. In combination with an increased throughput (up to 300%) and a reduced animal use (up to 50%), the enhanced power of the differential approach improves the utility of the biorelevant in situ perfusion technique with mesenteric blood sampling to elucidate the intestinal interaction profile of drugs and drug candidates. Copyright © 2010 John Wiley & Sons, Ltd. [source] The transplacental transfer of the macrolide antibiotics erythromycin, roxithromycin and azithromycinBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 6 2000Gynaecology), Tuija Heikkinen Consultant (Obstetrics Objective To investigate the transplacental transfer of the macrolide antibiotics erythromycin, roxithromycin and azithromycin. Methods Twenty-one term placentas were obtained with maternal consent immediately after delivery and a two-hour nonrecirculating perfusion of a single placental cotyledon was performed. Erythromycin (2 ,g/mL), roxithromycin (2 ,g/mL) and azithromycin (0.3 ,g/mL) were infused to the maternal inflow at a constant rate, with antipyrine as a reference compound, and their appearance in the fetal circulation was followed. Drug concentrations were measured by high performance liquid chromatography for 120 min. Results The mean transplacental transfers (TPTss) for erythromycin, roxithromycin and azithromycin were 3.0%, 4.3% and 2.6%, respectively, calculated as the ratio between the steady state concentrations in fetal venous and maternal arterial sides. Similar results were obtained when the TPT was calculated as the absolute amount of drug transferred across the placenta during 2-hour perfusion (TPTA). No significant differences were found among the three macrolides in TPTSS (P= 0.39) or TPTA (P= 0.35). The TPTSS of erythromycin, roxithromycin and azithromycin were 41%, 35% and 32% of the freely diffusable reference compound antipyrine, respectively. Steady state was reached in 60 minutes in each perfusion indicating sufficient perfusion time. Conclusion The limited transplacental transfer of erythromycin, roxithromycin and azithromycin suggests compromised efficacy in the treatment of fetal infections. On the other hand, the placenta seems to produce an effective barrier reducing the fetal exposure when these three macrolides are used to treat maternal infections. [source] ROLE OF HYPOTHALAMIC ,2 -ADRENOCEPTOR ACTIVITY IN FRUCTOSE-INDUCED HYPERTENSIONCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 10 2006Marcos A Mayer SUMMARY 1The aim of the present study was to investigate the effects of the ,2 -adrenoceptor antagonist yohimbine on blood pressure and heart rate (HR) regulation, as well as on adrenergic and serotoninergic neurotransmission, in fructose hypertensive (F) rats. 2The anterior hypothalamic area of control (C) and F rats was perfused with Ringer's solution containing 10 and 100 µg/mL yohimbine through a microdialysis concentric probe. The effects of yohimbine on mean arterial pressure (MAP) and HR, as well as on hypothalamic dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindole acetic acid (5-HIAA) levels, were measured according to perfusion time. 3Although intrahypothalamic perfusion of yohimbine increased blood pressure in C rats (,MAP 9 ± 1 and 11 ± 2 mmHg for 10 and 100 µg/mL yohimbine, respectively; P < 0.05 vs Ringer's perfusion), the ,-adrenoceptor antagonist did not modify MAP in F. Intrahypothalamic yohimbine had no effect on HR at either concentration tested. Intrahypothalamic perfusion of 10 and 100 µg/mL yohimbine increased DOPAC levels in C rats (135 ± 6 and 130 ± 5% of basal levels, respectively; both n = 6; P < 0.05 vs Ringer's perfusion), but not in F animals (115 ± 6 and 102 ± 6% of basal levels, respectively; both n = 6). In both C and F rats, yohimbine administration induced an increase in 5-HIAA dialysate levels. 4The results of the present study support the notion that ,2 -adrenoceptor tone of the anterior hypothalamus of normotensive rats, which contributes to normal blood pressure regulation, is not involved in the control of HR in either normotensive C or hypertensive F rats. The absence of changes in MAP after yohimbine perfusion in F rats suggests that the ,2 -adrenoceptor tone could be decreased in this group of rats and that this may be responsible for the maintenance of hypertension in this model. Intrahypothalamic perfusion of yohimbine increased DOPAC in the dialysate only in C rats, suggesting changes in presynaptic ,2 -adrenoceptor activity in fructose-overloaded rats. Conversely, increased 5-HIAA levels did not differ between C and F groups. [source] Risk Factors for Requirement of Permanent Pacemaker Implantation After Aortic Valve ReplacementJOURNAL OF CARDIAC SURGERY, Issue 3 2006Hasan Basri Erdogan M.D. Methods: Among 465 patients operated between 1994 and 2004, 19(4.1%) patients with a mean age 49.9 ± 17.2 years required the implantation of a permanent pacemaker. Eleven of them were female (57.9%). The main indication was aortic stenosis (89.5%). Severe annular calcification was documented in 78.9% of them, and the aortic valve was bicuspid in 57.9%. Results: Risk factors for permanent pacing after aortic valve replacement (AVR) identified by univariate analysis were female sex, hypertension, preoperative ejection fraction, aortic stenosis, annular calcification, bicuspid aorta, presence of right bundle branch block (RBBB) or left bundle branch block (LBBB), prolonged aortic cross-clamp and perfusion times, and preoperative use of calcium channel blockers. Multivariate analysis showed that female sex (p = 0.01, OR; 5.21, 95% CI: 1.48-18.34), annular calcification (p < 0.001, OR; 0.05, 95% CI: 0.01-0.24), bicuspid aortic valve (p = 0.02, OR; 0.24, 95% CI: 0.07-0.84), presence of RBBB (p = 0.009, OR; 0.03, 95% CI: 0.003-0.44) or LBBB (p = 0.01, OR; 0.13, 95% CI: 0.02-0.69), hypertension (p = 0.03, OR; 0.22, 95%CI: 0.05-0.89), and total perfusion time (p = 0.002, OR; 1.05, 95% CI: 1.01-1.08) were associated risk factors. Conclusion: Irreversible atrioventricular block requiring a permanent pacemaker implantation is an uncommon complication after AVR. Risk factors are annular calcification, bicuspid aorta, female sex, presence of RBBB or LBBB, prolonged total perfusion time, and hypertension. [source] | ||||||||||