• Proceedings of KOSOMES biannual meeting
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• 2007.05a
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• pp.97-99
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• 2007

대기중 이산화탄소 농도상승을 억제하기 위하여 $CO_2$를 해양에 처리하는 방안이 제안되고 있으며 해양생태계 및 해양생물에 대한 생물학적 영향에 대한 검토가 신중하게 검토되어야 할 것으로 생각된다. 본 연구에서는 고농도의 이산화탄소 환경에서 천해어종인 방어 및 넙치의 심혈관계 반용을 비교 검토하였다. 5% $CO_2$ 환경에서 방어는 8시간 이내에, 넙치는 48 시간 이내에 100% 폐사하였으며, 넙치는 혈액 pH가 회복하였음에도 불구하고 폐사하는 경향이었다. 방어의 cardiac output (심박출량)은 stroke volume (박동량)의 변화에 의해서 영향을 받으며, 넙치는 heart rate (심박수)의 변화가 심박출량의 변화에 큰 영향을 끼치는 것으로 나타났다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.473-476
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• 2010

본 논문에서는 심폐기능에 이상이 있는 중환자의 상태를 진단하기 위한 방법으로 Swan-Ganz Catheter를 체내에 삽입하여 심박 출량과 혼합정맥혈 산소포화도를 기존 장비들보다 정밀하게 측정할 수 있는 모듈을 개발하고자 한다. Swan-Ganz Catheter에는 두 개의 온도센서와 세 개의 압력센서를 포함하고 있으며 이를 통해 입력되는 센서 값을 세밀하게 수집하고 이를 기반으로 일회 심박출량, 전신 및 폐혈관저항, 산소소모량 등을 계산하여 환자의 상태를 보다 정확하게 진단 및 치료가 가능하게 한다.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1205-1213
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• 1997

This study reviewed useful aspects of the intraoperative transesophageal echocardiography among the patients in whom heart surgery were undertaken between January 1996 and July 1996 at St.Pauls hospital, Medical College of Catholic University, Seoul, Korea. During that period, 61 patients were operated on because of valvular heart disease(25 patients), coronary artery disease(22 patients), congenital heart disease(13 patients), and combined coronary artery disease and valvular heart disease(1 patient). Two patients(1 redo-VSD and 1 valvular heart diease) needed repeated aortic cross clamping and complementary procedures because of incomplete initial procedures. There was no incidence of air embolism. We could observe significant relationship of cardiac output monitoring methods either by thermodilution technique and transesophageal echocardiography by linear regression analysis(p<0.001). We tested myocardial response(percentage of systolic wall thickness, PSWT) with low dose dobutamine challenge to predict post-CABG myocardial perfusion. And the test showed statistically significant resp.onse(sensitivity 76%, specificity 94.7%, positive predictive value 95%, negative predictive value 75%). These results suggest that cardiac surgeon could draw more benefits by intraoperative transesophageal echocardiography.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.140-152
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• 1998

Background: Prone position improves oxygenation in patients with ARDS probably by reducing shunt Reduction of shunt in prone position is thought to be effected by lowering of the critical opening pressure (COP) of the dorsal lung because the pleural pressure becomes less positive in prone position compared to supine position. It can then be assumed that prone position would bring about greater improvement in oxygenation when PEEP applied in supine position is just beneath COP than when PEEP is above COP. Hemodynamically, prone position is expected to attenuate the lifting of cardiac fossa induced by PEEP. Based on these backgrounds, we investigated whether the effect of prone position on oxygenation differs in magnitude according to the level of PEEP applied in supine position, and whether impaired cardiac output in supine position by PEEP can be restored in prone position. Methods: In seven mongrel dogs, $PaO_2/F_1O_2$(P/F) was measured in supine position and at prone position 30 min. Cardiac output (CO), stroke volume (SV), pulse rate (PR), and pulmonary artery occlusion pressure (PAOP) were measured in supine position, at prone position 5 min, and at prone position 30 min. After ARDS was established with warmed saline lavage(P/F ratio $134{\pm}72$ mm Hg), inflection point was measured by constant flow method($6.6{\pm}1.4cm$ $H_2O$), and the above variables were measured in supine and prone positions under the application of Low PEEP($5.0{\pm}1.2cm$ $H_2O$), and Optimal PEEP($9.0{\pm}1.2cm$ $H_2O$)(2 cm $H_2O$ below and above the inflection point, respectively) consecutively. Results : P/F ratio in supine position was $195{\pm}112$ mm Hg at Low PEEP and $466{\pm}63$ mm Hg at Optimal PEEP(p=0.003). Net increase of P/F ratio at prone position 30 min, however, was far greater at Low PEEP($205{\pm}90$ mm Hg) than at Optimal PEEP($33{\pm}33$ mm Hg)(p=0.009). Compared to CO in supine position at Optimal PEEP($2.4{\pm}0.5$ L/min), CO in prone improved to $3.4{\pm}0.6$ L/min at prone position 5 min (p=0.0180) and $3.6{\pm}0.7$ L/min at prone position 30 min (p=0.0180). Improvement in CO was attributable to the increase in SV: $14{\pm}2$ ml in supine position, $20{\pm}2$ ml at prone position 5 min (p=0.0180), and $21{\pm}2$ ml at prone position 30 min (p=0.0180), but not to change in PR or PAOP. When the dogs were turned to supine position again, MAP ($92{\pm}23$ mm Hg, p=0.009), CO ($2.4{\pm}0.5$ L/min, p=0.0277) and SV ($14{\pm}1$ ml, p=0.0277) were all decreased compared to prone position 30 min. Conclusion: Prone position in a dog with saline-lavaged acute lung injury appeared to augment the effect of relatively low PEEP on oxygenation, and also attenuate the adverse hemodynamic effect of relatively high PEEP. These findings suggest that a PEEP lower than Optimal PEEP can be adopted in prone position to achieve the goal of alveolar recruitment in ARDS avoiding the hemodynamic complications of a higher PEEP at the same time.

• Journal of Korean Academy of Nursing
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• v.40 no.3
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• pp.433-441
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• 2010

Purpose: This study was performed to identify effects of pneumoperitoneum on hemodynamic changes of hypertensive patients undergoing laparoscopic colectomy under general anesthesia. Methods: Data collection was done from January 2 to June 10, 2008. Seventy-six patients, including 38 hypertensive patients, who had taken antihypertensive drugs more than 1 month and 38 normotensive patients undergoing laparoscopic colectomy were enrolled in this study. The hemodynamic parameters were heart rate (HR), mean arterial pressure (MAP) and cardiac output (CO) which were measured 7 times from before induction of anesthesia to 5 min after deflation of the pneumoperitoneum. Collected data were analyzed using Repeated Measures ANOVA and Bonferroni comparison method. Results: HR in the hypertensive group was significantly decreased at deflation of the pneumoperitoneum and 5 min after deflation of the pneumoperitoneum (p=.012). MAP in the hypertensive group was not different from the normotensive group (p=.756). CO in hypertensive group was significantly lower than normotensive group (p<.001) from immediately after pneumoperitoneum to 5 min after deflation of the pneumoperitoneum. Conclusion: The results indicate that pneumoperitoneum during laparoscopic surgery does not lead to clinically negative hemodynamic changes in heart rate, mean arterial pressure or cardiac output of hypertensive patients, who have taken antihypertensive drugs for more than 1 month.

• The Korean Journal of Nuclear Medicine
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• v.4 no.2
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• pp.11-27
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• 1970

Cardiac output, plasma volume and renal plasma flow were determined to evaluate hemodynamic changes in 29 patients with cirrhosis of the liver. The results obtained were as follows. 1. The mean plasma volume was 3793+895ml and it was significantly higher than the normal controls. The mean blood volume ($5266{\pm}1222ml$) and blood volume per kg body weight ($95.7{\pm}23.41ml$) were also increased significantly. The mean plasma volume per kg body weight ($69.1{\pm}19.1ml$) showed increased tendency and the mean difference between blood volume and plasma volume per kg body weight ($26.4{\pm}7.05ml$) was in lower limit of normal range. 2. The mean cardiac output was $7708{\pm}2652ml/min$ and it was significantly increased. The mean cardiac index ($4924{\pm}1998ml/min/M^2$), stroke volume ($96.2{\pm}34.2ml/beat$), stroke index ($62.3{\pm}27.34ml/M^2$) and fractional cardiac index ($1.54{\pm}0.577$) were also increased significantly. The mean total -peripheral resistance was $1664{\pm}753.8\;dynes\;sec\;cm^{-5}M^2$ and it was significantly lower than the normal controls. 3. The mean renal plasma flow was $537{\pm}146.8ml/min/1.73M^2$ and it was normal to decreased tendency. The mean endogenous creatinine clearance ($66.7{\pm}23.0ml/min/1.73M^2$) was significantly decreased. Filtration fraction was variable, but it was slightly lower than normal in most cases. The mean renal fraction of cardiac output ($11.4{\pm}6.27%$) was relatively decreased. 4. Although renal plasma flow was normal or decreased in general, it was definitely diminished in patients with creatinine clearance less than $60ml/min/1.73M^2$, resistant ascites, and signs of azotemia (elevated BUN and serum creatinine). 5. Diminished glomrular filtration rate with low filtration fraction and decreased renal fraction of cardiac output observed strongly supported increased renal afferent arteriolar resistance. 6. Renal circulatory impairment preceded azotemia or oroliguria in cirrhosis. 7. Clinical findigns and liver function were not correlated with hemodynamic changes, except for esophageal varices associated with high cardiac output obsedved. 8. No definite correlation of renal hemodynamics with plasma volume or cardiac output was found.

• Journal of Biomedical Engineering Research
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• v.9 no.2
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• pp.165-170
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• 1988

The purpose of this study was to prove the accuracy of impedance cardiography by measuring cardiac outputs of patients simultaneously by thermodilution method, and impedance cardiography developed in our department. The subjects were eight patients with mitral stenosis admitted to the cathete rization laboratory in Severance Hospital. The correlation coefficient was 0.895, which is thought quite high considering the fact that accuracy of cardiac outputs of patients with valvular diseases measured by both methods was known to be low.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.549-552
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• 2009

본 논문에서는 심폐기능에 이상이 있는 중환자의 지속적인 감시와 진단을 위한 방법으로 Swan-Ganz Catheter를 체내에 삽입하여 심박 출량과 혼합정맥혈 산소포화도를 기존 장비들보다 정밀하게 측정할 수 있는 모듈을 개발하고자 한다. Swan-Ganz Catheter에는 두 개의 온도센서와 한개의 압력센서를 포함하고 있으며 이를 통해 입력되는 센서 값을 세밀하게 수집하고 이를 기반으로 일회 심박 출량, 전신 및 폐혈관저항, 산소소모량 등을 계산하여 환자의 상태를 보다 정확하게 진단 및 치료가 가능하게 한다.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.769-773
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• 2010

Systemic hypotension has been traditionally used to facilitate deployment of thoracic stent grafts. Decreasing blood pressure with vasodilating agents further increases cardiac output and, consequently, the cardiac output-mediated windsock effect during deployment. Use of rapid ventricular pacing reduces the windsock effect during stent graft deployment and allows the graft to appose to the aortic wall under zero cardiac output, thus minimizing aortic wall shear stress. In this case we report the use of transvenous rapid ventricular pacing, a safe and reproducible technique to allow precise deployment of a Valiant Captivia stent graft in the distal thoracic arch for a saccular thoracic aneurysm.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.54-62
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• 1990

The thermodiluton is a standard method to measure cardiac output in clinical medicine. However it has many disadvantages such as expensive instrument and measurement, limited number of measurement, pain, safety problem, and side-effect due to insertion of catheter into heart. Electrical Impedance Cardiography has no such disadvantages and that it can continuously monitor stroke volume, contractility of cardiac muscle, and systolic time interval (STI) as well as cardiac output. While this impedance technique has been widely used and vigorously studied adroad, it is not introduced yet in Korea. Thus an Impedance Cardiograph has been developed in order to introduce this new technique. Its accuracy also has been verified by simultaneous measurement of cardiac output with the thermodilution technique. Finally changes of cardiac function during exercise were also measured.