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Background: Axillary block is used for inducing anesthesia in outpatient hand and forearm surgeries. Few researches have studied hemodynamic and blockade effects of low doses of Epinephrine. The aim of the present study was to compare the duration of analgesia and hemodynamic changes following the injection of high/low epinephrine doses in such surgeries. Methods: The present randomized clinical trial study was conducted on healthy individuals (ASA I-II) who were candidates for hand and forearm surgeries. The patients were randomly divided into three groups. The first two groups were allocated to receive lidocaine with low (0.6μg/cc) and high (5μg/cc) doses of epinephrine whereas lidocaine plus normal saline was injected in the third group. The hemodynamic changes (Mean arterial blood pressure and heart rate) and the occurance of any side-effects along with the duration of analgesia and motor block were recorded. Results: From among the total of 75 patients, 15 cases were excluded due to incomplete blockade or failure needing general anesthesia. The duration of analgesia and the motor block were longer in the high dose epinephrine group, the difference, however, was not statistically significant. Heart rate changes within the groups was significant in the 4th- 7th and 10th minutes. Mean arterial blood pressure changes was only significant in the 4th minute, within the groups. Conclusions: Administering low doses of epinephrine plus lidocaine as a local anesthetic not only provides acceptable analgesia compared to higher doses of the medication, but also is associated with fewer side effects. [ABSTRACT FROM AUTHOR]

Mechanical valve malfunction due to thrombosis is an important and life-threatening complication in patients with prosthetic valves. Our study was performed to determine the prevalence of thrombophilia genes among patients with acute thrombosis of the mechanical pulmonary valves despite acceptable anticoagulation levels. In this cross-sectional comparative study thirthy two consecutive patients with acute thrombosis of pulmonary mechanical valve who had international normalized ratio (INR) levels for prothrombin time of at least 2 at the time of presentation and in the preceding three months were enrolled and the prevalence rates of thrombophilia factor genes among them was assessed. The results showed that 24 patients (75%) had thrombophilia gene mutations. The affected patients had mutations in one gene in 37.5% of cases, two genes in 31.3%, and three genes in 6.3%. Prevalence rate of Factor V Leiden (FVL), prothrombin (PTH), Plasminogen activator inhibitor-1 (PAI-I), Methylenetetrahydrofolate Reductase (MTHFR), and endothelial protein C receptor (EPCR) gene mutations was 3.1%, 6.3%, 50%, 37.5%, and 25%, respectively. In our study the prevalence of thrombophilia factor gene mutations of patients with acute thrombosis of pulmonary valve was higher than that reported in the general population. [ABSTRACT FROM AUTHOR]

Background: The evaluation of prosthetic valves is very difficult with two-dimensional transthoracic echocardiography alone. Doppler and color flow imaging as well as transesophageal echocardiography are more reliable to detect prosthetic valve dysfunction. However, Doppler study sometimes tends to be misleading due to the load-depending characteristics of peak and mean pressure gradients. The peak-to-mean pressure decrease ratio is a load-independent measure, which was previously used for the detecting and grading of aortic valve stenosis. We assessed the usefulness of this method for the evaluation of aortic valve prosthesis obstruction.Methods: One hundred fifty-four patients with aortic valve prostheses were included in this study. Transthoracic and transesophageal echocardiographic examinations were performed in all the patients. Peak velocity and velocity time integral of the aortic valve and left ventricular outflow tract, peak and mean aortic valve pressure gradients, peak-to-mean pressure gradient ratio, and time velocity integral (TVI) index were measured.Results: There was a significant relation between the TVI index (p value < 0.001) and aortic prosthesis obstruction. A TVI index < 0.2 had a sensitivity of 71% and specificity of 100% for the detection of aortic valve prosthesis obstruction. However, no significant relation was found between the peak-to-mean pressure ratio and aortic valve prosthesis obstruction (p value = 0.09).Conclusion: Although the peak-to-mean pressure gradient (PG/MG) ratio is a simple, quick, and load-independent method which may be useful for the grading of aortic valve stenosis, it is poorly associated with aortic valve prosthesis obstruction. The TVI index is a useful measure for the detection of aortic prosthesis obstruction. [ABSTRACT FROM AUTHOR]

Background: Echocardiography is the most common test used for the evaluation of aortic regurgitation (AR). However, the role of echocardiography as an available and inexpensive method in the quantification of AR by the left ventricle to right ventricle stroke volume ratio (LV/RV SV ratio) has not been completely investigated.Methods: Between June 2005 and December 2007, 132 consecutive patients with AR (mean age: 44.7+/-14.6 years, 52.3% male) were enrolled in the study. All the patients underwent echocardiography; and aortography, if indicated, was performed as well.Results: Fifty-two percent of the patients had severe AR. There was almost a perfect agreement between echocardiography and cardiac catheterization in determining the severity of AR (Kappa=0.81). Associated valvular disease was found in 81.8% of the patients, the most common disease being mitral regurgitation (61%). The results of our bivariate and multivariate analyses showed a significant relation between the LV/RV SV ratio and the AR severity via either echocardiography or cardiac catheterization (both P=0.001). The receiver operating characteristic (ROC) curve analysis showed that the LV/RV SV ratio was very accurate in the detection of severe AR utilizing cardiac catheterization as the gold standard (AUC=0.71). The cut point value of the LV/RV SV ratio

Due to the production of hydrogen, using fuel cells for energy conversion and storing encounters safety problems. Combining high-temperature solid oxide fuel cells with photovoltaic solar panels or zinc oxide solar panels can be a good candidate to produce/convert and store the energy more efficiently for using at peak times. The current paper intends to analyze the efficiency of integration of zinc oxide solar panels and fuel cells to produce hydrogen directly. Therefore, the excess step of converting electricity to hydrogen and re-converting it to electricity, which is customarily used for the integration of the photovoltaic and solid oxide fuel cells, could be skipped. The new method paves the way for providing the required energy for heating/cooling through the floor heating and ceiling cooling systems as well as generating electricity. The article also demonstrates that it is possible to have heat during the day and night for an area of 1920 m 2 and 542 m 2 . It is also possible to create coolness during the day and night for an area of 925 m 2 and 260 m 2 . [ABSTRACT FROM AUTHOR]