• Journal of Chest Surgery
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• v.21 no.6
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• pp.970-978
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• 1988

There is tendency of increasing number and decreasing age of patients who are indicated for Rastelli operation for their cyanotic congenital heart disease. So there is the need to find the criterion which saves the patients from early postoperative hemodynamic disturbances. We reviewed the 26 patients who had been performed Rastelli operation at Seoul national University Hospital from January 1981 to June 1988. mean age of the patients was 7.8*3.4 years[range 2.5-15years], mean body surface area[BSA] 0.79*0.25m2[range 0.49-1.51m2] and mean hematocrit 57.95*12%[range 48-80%]. We divided these patients into survived group and died group before postoperative 72 hours, and analyzed preoperative arterial oxygen saturation[SaO2], the ratio of diameter of right pulmonary artery to ascending aorta[RPA/AA], the ratio of both right and left pulmonary artery diameter to descending thoracic aorta[RPA+LPA/DTA], pulmonary artery index[PA index], cardiopulmonary bypass time, aorta cross-clamping time, postoperative perfusion state and total amount of dopamine infused postoperatively. The results showed that RPA+LPA/DTA and PA index were statistically significant factors to influence early postoperative cardiac death rate[P< 0.05]. Especially there were good linear correlations between PA index[X] and peripheral perfusion index[Y][Y= - 1.15+0.02 X, r=0.86, P<0.01]and between PA index[X] and total amount of dopamine infused before postoperative 72 hours[mg/kg, Y][Y=61.94 - 0.15 X, r=-0.80, P < 0.01]. Also there were tendencies that the higher RPA+LPA/DTA[Y], the better peripheral perfusion [X] and the lower need of dopamine[X], but no statistical significance.[Y=0.78+1.60 X, r =0. 49, P >0.05] And the discriminate analysis showed that patients with PA index over 221 mm2/BSA could undergo correction with 25 per cent of error rate. In conclusion, early postoperative hemodynamic states could be predicted by preoperatively measured PA index, and which can be used as a criterion for Rastelli operation performed on cyanotic congenital heart disease.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.563-567
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• 2008

Background: The histomorphological properties of the left anterior desecending artery (LAD), the left internal thoracic arteries (LITA), the radial arteries (RA) and the intercostal arteries (ICA) were studied for their use as a conduit for coronary artery bypass grafting (CABG), and we compared them with each other. Material and Method: All the vessels were harvested from nineteen cadavers (17 males and 2 females). The mid-portion of the LAD, the mid-portion of the LITA, the distal RA and the mid-portion of the 5th ICA were obtained. All of them were stained with hematoxylin-eosin and with Van Gieson's elastin stain. The morphological characteristics were examined and the thicknesses of the intima and media (I/M ratio: the intima to media ratio) were compared using one-way ANOVA tests. Result: The mean age of the cadavers was $61.5{\pm}9.6$ years. The LITA and ICA were elastic arteries, and the LAD and RA were muscular arteries. The I/M ratio showed statistically significant differences: $0.07{\pm}0.03$ in the LITA, $0.16{\pm}0.11$ in the ICA, $0.45{\pm}0.29$ in the RA and $0.93{\pm}0.52$ in the LAD, respectively. Conclusion: This study showed that the degrees of intimal hyperplasia of the CA and the various conduits for CABG were different significantly. The ICA was found to have relatively favorable characteristics as a coronary by pass conduit, but its suitability for clinical use is a challenging issue.

• Journal of Chest Surgery
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• v.13 no.2
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• pp.85-91
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• 1980

Extracorporeal circulation by hemodilution technique has been currently used with its clinical safety and good peripheral tissue perfusion in open heart surgery. There is no doubt that $O_{2}$ carrying capacity of the blood is disturbed by decreased hemoglobin level resulting from hemodilution of the circulating blood. From the view point of the blood gas exchange, these experimental studies were undertaken to determined the sate limit of hemodilution in the condition of cardiopulmonary bypass with a constant perfusion flow rate. Twelve adult mongrel dogs weighing 10 to 13 Kg. were anesthetized with pentobarbital and then respiration was controlled with Harvard volume respirator using room air. The cardiopulmonary by pass was performed by use of Sarns heart lung machine (console 5000, 5 head and 2 roller pumps) and Travenol pediatric bubble oxygenator. The perfusion rate during bypass was maintained at a constant rate of 80 ml/min/Kg of body weight. The ratio of oxygen gas flow to blood flow was kept in 3 to 1 constantly. International hemodilution was attained by serial blood withdrawals and immediate infusion of equal volumes of diluants composed of Ringer's lactate, 5% dextrose in water and 25% mannitol solution, proportionally 60%, 30%, and 10%. Arterial and venous blood samples were obtained between 15 and 20 minutes following each hemodilution. Hematocrits and hemoglobin values, $PO_{2}$, $PCO_{2}$ and pH were measured. Oxygen and carbon dioxide contents oxygen consumption and carbon dioxide elimination were calculated groups according to different hematocrit values and the correlations were evaluated. Result were as follows. 1. the arterial $O_{2}$ tension and $O_{2}$ saturation were maintained at the physiological level irrespective of the hematocrit value. 2. The venous $O_{2}$ tension and $O_{2}$ saturation showed a tendency to decline with the decrease in hematocrit value and positive correlation between them (r = +0.49, r = +0.76), The mean values of venous $O_{2}$ tension and $O_{2}$ saturation, however, were not decreased when the hematocrit levels were lower than 20%. 3. The arterial $O_{2}$ content declined lineally in proportion to the fall of hematocrit level with a positive correlation between them (r = +0.95). 4. The venous $O_{2}$ contents were decreased gradually as the hematocrit value decreased with positive correlation between them ( r =+0.89). The trend of diminution of venous $O_{2}$ content, however, was became low according to progressive decrease of hematocrit level. 5. Systemic oxygen consumption was in higher range than $O_{2}$ requirement of basal metabolism when the hematocrit value was above 20%, but abruptly decreased when the hematocrit value became to below 20%. 6. The arterial $CO_{2}$ tension and $CO_{2}$ content showed trend of increasing with progressive decrease of hematocrit value but exhibited a rather broad range and there was no relationship between those value and the hematocrit value. 7. The venous $CO_{2}$ tension and $CO_{2}$ content have also no correlation with change of Ht. value but related directly to those value of arterial blood with positive correlation between them (r = +0.78, r = +0.95_. 8. A-V difference of $CO_{2}$ content and $CO_{2}$ elimination wasnot significantly influenced by Ht. value. From the results, we obtained that feasible limit in inteneional hemodilution is above the hematocrit value of 20% under the given experimental condition.

• Journal of Chest Surgery
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• v.31 no.1
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• pp.32-39
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• 1998

High-dose aprotinin(Hammersmith regimen) has been widely used for years to control postoperative bleeding and reduce blood consumption in cardiac surgery but had known to cause some side-effects and had disadvantage in cost-effectiveness. The prospective controlled study of 33 patients undergoing cardiopulmonary bypass was performed to evaluate the efficacy for reducing postoperative bleeding and unfavorable effects of low-dose aprotinin. The level of hemoglobin and platelet in the blood and the amount of postoperative bleeding were assessed preoperatively, and postoperatively for the study of hemostatic function. The level of BUN and serum creatinine in the blood, levels of urine creatinine, total protein, albumin, alpha-1-microglobulin and creatinine clearance were assessed before and after the operation for the study of renal function. The aprotinin group had a significant reduction in chest tube drainage; 243$\pm$ 123 ml versus 406$\pm$303 ml(P=0.037) during 6 hours immediate-postoperatively, 494$\pm$358 ml versus 869$\pm$570 ml(P=0.045) during 24 hours postoperatively. The ratio of alpha-1-microglobulin/creatinine and microalbumin/creatinine in the urine were slightly increased in the aprotinin group postoperatively in comparison with the control group but there were no statistically significant difference(55$\pm$23 versus 24$\pm$10 in the alpha-1-microglobulin/creatinine, 56$\pm$19 versus 38$\pm$25 in the microalbumin/creatinine at post- operative 3rd day). There were no significant difference between two groups in other parameters of renal function, too. This study showed that low-dose aprotinin is an effective means of reducing postoperative bleeding without inducing significant renal dysfunction.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.10
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• pp.711-718
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• 2014

Investigated the processing characteristics of the pollutants and runoff due to storm events in the actual application of the road fields and a Non-Point Sources (NPS) pilot scale equipment. This phenomenon has occurred in the influent bypass the blockage occurs after 90 min the expended polymeric media was filled with filtered column. When entering a treatment tank SS 200 mg/L or more high concentration of effluent treatment efficiency was reduced from the reaction time 60 min. Influent concentration less then SS 180 mg/L was stable handling. The $COD_{Cr}/SS$ ratio were analyzed with 0.67, median value. Showed 92.1% and 82.3% respectively with an average removal rate of the SS and the $COD_{Cr}$. If the influent concentration of TP is the 0.5 mg/L or less, the quality of the treated water is 0.1 mg/L levels were expressed in a stable process. And when entering the 1.0 mg/L or more of the treated water, had a greater than average 0.2 mg/L. If the influent concentration of TN is 4~10 mg/L, the treatment water quality level was kept a 1.5~3.0 mg/L. The average removal efficiency of TP and TN respectively 73.9%, 50.4%.

• Journal of Chest Surgery
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• v.47 no.3
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• pp.255-261
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• 2014

Background: To determine the predictors of clinical outcomes following surgical descending thoracic aortic (DTA) repair. Methods: We identified 103 patients (23 females; mean age, $64.1{\pm}12.3$ years) who underwent DTA replacement from 1999 to 2011 using either deep hypothermic circulatory arrest (44%) or partial cardiopulmonary bypass (CPB, 56%). Results: The early mortality rate was 4.9% (n=5). Early major complications occurred in 21 patients (20.3%), which included newly required hemodialysis (9.7%), low cardiac output syndrome (6.8%), pneumonia (7.8%), stroke (6.8%), and multi-organ failure (3.9%). None experienced paraplegia. During a median follow-up of 56.3 months (inter-quartile range, 23.1 to 85.1 months), there were 17 late deaths and one aortic reoperation. Overall survival at 5 and 10 years was $80.9%{\pm}4.3%$ and $71.7%{\pm}5.9%$, respectively. Reoperation-free survival at 5 and 10 years was $77.3%{\pm}4.8%$ and $70.2%{\pm}5.8%$. Multivariable analysis revealed that age (hazard ratio [HR], 1.10; 95% confidence interval [CI], 1.05 to 1.15; p<0.001) and left ventricle (LV) function (HR, 0.88; 95% CI, 0.82 to 0.96; p<0.003) were significant and independent predictors of long-term mortality. CPB strategy, however, was not significantly related to mortality (p=0.49). Conclusion: Surgical DTA repair was practicable in terms of acceptable perioperative mortality/morbidity as well as favorable long-term survival. Age and LV function were risk factors for long-term mortality, irrespective of the CPB strategy.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.627-634
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• 2010

Background: The durability of the tissue valve is important in choice between a mechanical valve and a tissue valve in cardiac surgery. We studied the mid-term results of tissue valve in the aortic position. Material and Method: The subjects were 380 patients who had undergone aortic prosthesis replacement between May 1990 and March 2009. We retrospectively analyzed hospital and outpatient records: the mean age was $69{\pm}9$ years; the male to female ratio was 227 : 162; and the mean follow-up duration was $46.7{\pm}40.8$ months (range 0~196 months). Result: 389 surgical cases in total had been taken with 380 patients. Early death occurred in 15 patients (3.9%). Overall survival rate at 1, 5 and 10 years were 92.3%, 78.1% and 54.2% respectively. Freedom from reoperation at 1, 5 and 10 years were 98.4%, 97.1% and 91.7% respectively. Freedom from structural valvular deterioration at 1, 5 and 10 years were 96.1%, 92.3% and 88.0% respectively. In the multivariate analysis of preoperative risk factors, young age (p<0.001) was significant risk factor for reoperation. High peak velocity in the postoperative period (p=0.034) and young age (p=0.029) were significant risk factors for structural valvular deterioration. Old age (p=0.001), long bypass time (p=0.035), concomitant coronary artery bypass graft surgery (p=0.003) and preoperative low left ventricular ejection fraction (p=0.003) were significant factors for early mortality. Preoperative estimated glomerular filtration rate (< 60 mL/min) (p=0.025) and persistent left ventricular hypertrophy (p=0.032) were the risk factors for late mortality. Conclusion: This study showed that the freedom from reoperation and the freedom from structural valvular deterioration in aortic tissue valve replacement were acceptable. It will be necessary to conduct further studies with long-term follow-up and more patients.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.282-286
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• 1997

In the era of coronary artery bypass grafting, the intraaortic balloon pump (IABP) is more widely used and its indication has been ex anded. We perf'orbed retrospective clinical analysis on the patients who have received IABP pre andfor postoperatively during the course of CABG. From January 1981 to June 1995, total 322 patients have received CABG at the Seoul National University Hospital and among them 50 patients (15.5%) were supported by IABP during the course of the operation. The mean age at the time. of the operation was 57.2 years (39∼ 75 years) and the male to female ratio was 33 : 17. The preoperative diagnosis was unstable angina in 33 (66%), stable angina in 7 (14%) and postinfarct angina in 8 patients(16%). As for the indications of the IABP, there were 13 cases(26%) with left main disease, 13 (26%) with class IV angina, 12 (24%) with difficulty in CPB weaning, 6 (12%) with postinfarct angina and 3 (6%) with severe LV dysfunction. In the remaining 3 cases, one patient was operated on after PTCA failure in emergency basis, another was a patient with AMI, and the other was one who had postoperative low c rdiac output syndrome. All IABPS were introduced via femoral artery and among them 45 cases (90%) percutaneously. The mean postoperative assist time was 22.3 hours (0.5 ∼ 168 hours) and IABP could be removed within 48 hours in most of them (44150). The operative mortality was 6.1% (3 cases) and postoperative morbidity was only one with lower extremity ischemia. The more general application of the IABP during the course of the CABG ,especially in patients with high preoperative risk factors or difficulty in CPB weaning is a good measure of protecting and recovering myocardial function with minimal risk.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2B
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• pp.187-192
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• 2011

Nitrate nitrogen is common contaminant in groundwater aquifers, its concentration is regulated many countries below 10 mg/L as N (As per WHO standards) in drinking water. An attempt was made to get optimal results for the treatment of nitrate nitrogen in groundwater by conducting various experiments by changing the experimental conditions for ZVI bipolar packed bed electrolytic cell. From the experimental results it is evident that the nitrate nitrogen removal is more effective when the reactor conditions are maintained in acidic range but when the acidic environment changes to alkaline due to the hydroxide formed during the process of ammonia nitrogen there by increasing the pH reducing the hydrogen ions required for reduction which leads to low effectiveness of the system. In the ZVI bipolar packed bed electrolytic cell, the packing ratio of 0.5~1:1 was found to be most effective for the treatment of nitrate nitrogen because ZVI particles are isolated and individual particle act like small electrode with low packing ratio. It is seen that formation of precipitate and acceleration of clogging incrementally for packing ratio more than 2:1, decreasing the nitrate nitrogen removal rate. When the voltage is increased it is seen that kinetics and current also increases but at the same time more electric power is consumed. In this experiment, the optimum voltage was determined to be 50V. At that time, nitrate nitrogen was removed by 94.9%.

• Fire Science and Engineering
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• v.27 no.3
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• pp.30-37
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• 2013

The ultimate purpose of the present study is to secure a effective method for foam liquid discharge when the mixing ratio deviates from the permissible range due to a decrease in the bypass flow rate resulting from a decrease in the cross sectional area of the foam liquid piping ranging from the branching header of one foam proportioner to the branching headers of multiple branching foam fire-extinguishing systems in the region for fire extinguishing and then to the standpipe at the lower part of the storage tank when a fire occurred in a combustible tank. To this end, the cause of mixing ratio variations following changes in the flow rates of existing foam fire extinguishing systems was analyzed, methods for compensation for constant mixing ratios were investigated, and it was proved that metering orifice replacements that could expand the cross sectional area of the stock solution inhaling piping was the most effective way for the improvement of form fire extinguishing systems' mixing ratios through foam proportioner venturi, foam chamber orifice, and metering orifice replacement experiments.