• Title/Summary/Keyword: Tidal volume

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Anesthetic Effect of Different Ratio of Ketamine and Propofol in Dogs

  • Lee, Mokhyeon;Kim, Sohee;Moon, Chawnghwan;Park, Jiyoung;Lee, Haebeom;Jeong, Seong Mok
    • Journal of Veterinary Clinics
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    • v.34 no.4
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    • pp.234-240
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    • 2017
  • Use of ketamine and propofol combination (so-called Ketofol) anesthesiain a fixed ratio (1:1 mg/ml) was reported in dogs. The use of ketofol reduced cardiovascular suppression, but respiratory-related side effects was not significantly different from propofol alone. In this study, we evaluated the quality of ketofol anesthesia and changes in cardiopulmonary function according to the ratio of ketamine to propofol. The experimental groups were divided into three groups: propofol alone (P group), 3:7 ketofol group (PK1 group) and 1:1 ketofol group (PK2). For each group, the dose of 0.8 ml/kgwas administered intravenously at a constant rate until the tracheal intubation was possible and anesthesia was maintained with isoflurane for 120 minutes after induction of anesthesia. There was no significant difference in the anesthetic quality among three groups. Also, there was no difference in respiratory rate, tidal volume, end-tidal carbondioxide, and oxygen saturation. In group P, heart rate was not changed significantly during anesthesia, but arterial blood pressure decreased, while heart rate and arterial blood pressure increased significantly in group PK2. In the PK1 group, heart rate and arterial blood pressure during anesthesia remained similar to pre-anesthetic values. In conclusion, ketofol might be used as induction agent, and 3:7 ratioof ketofol showed more safe and effective anesthetic effect in dogs. Additionally, 1:1 ketofol may be used in patients with severe bradycardia orhypotension with close monitoring during anesthesia.

The Cross-Sectional Characteristic and Spring-Neap Variation of Residual Current and Net Volume Transport at the Yeomha Channel (경기만 염하수로에서의 잔차류 및 수송량의 대조-소조 변동과 단면 특성)

  • Lee, Dong Hwan;Yoon, Byung Il;Woo, Seung-Buhm
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.5
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    • pp.217-227
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    • 2017
  • The object of this study is to estimate the net volume transport and the residual flow that changed by space and time at southern part of Yeomha channel, Gyeonggi Bay. The cross-section observation was conducted at the mid-part (Line2) and the southern end (Line1) of Yeomha channel for 13 hours during neap and spring-tides, respectively. The Lagrange flux is calculated as the sum of Eulerian flux and Stokes drift, and the residual flow is calculated by using least square method. It is necessary to unify the spatial area of the observed cross-section and average time during the tidal cycle. In order to unify the cross-sectional area containing such a large vertical tidal variation, it was necessary to convert into sigma coordinate system by horizontally and vertically for every hour. The converted sigma coordinate system is estimated to be 3~5% error when compared with the z-level coordinate system which shows that there is no problem for analyzing the data. As a result, the cross-sectional residual flow shows a southward flow pattern in both spring and neap tides at Line2, and also have characteristic of the spatial residual flow fluctuation: it northwards in the main line direction and southwards at the end of both side of the waterway. It was confirmed that the residual flow characteristics at Line2 were changed by the net pressure due to the sea level difference. The analysis of the net volume transport showed that it tends to southwards at $576m^3s^{-1}$, $67m^3s^{-1}$ in each spring tide and neap tide at Line2. On the other hand, in the control Line1, it has tendency to northwards at $359m^3s^{-1}$ and $248m^3s^{-1}$. Based on the difference between the two observation lines, it is estimated that net volume transport will be out flow about $935m^3s^{-1}$ at spring tide stage and about $315m^3s^{-1}$ at neap tide stage as the intertidal zone between Yeongjong Island and Ganghwa Island. In other words, the difference of pressure gradient and Stokes drift during spring and neap tide is main causes of variation for residual current and net volume transport.

Difference in Patient's Work of Breathing Between Pressure-Controlled Ventilation with Decelerating Flow and Volume-Controlled Ventilation with Constant Flow during Assisted Ventilation (보조환기양식으로서 감속형유량의 압력-조절환기와 일정형유량의 용적-조절환기에서 환자의 호흡일의 차이)

  • Kim, Ho-Cheol;Park, Sang-Jun;Park, Jung-Woong;Suh, Gee-Young;Chung, Man-Pyo;Kim, Ho-Joong;Kwon, O-Jung;Rhee, Chong-H.
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.6
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    • pp.803-810
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    • 1999
  • Background : The patient's work of breathing(WOBp) during assisted ventilation may vary according to many factors including ventilatory demand of the patients and applied ventilatory setting by the physician. Pressure-controlled ventilation(PCV) which delivers gas with decelerating flow may better meet patients' demand to improve patient-ventilator synchrony compared with volume-controlled ventilation(VCV) with constant flow. This study was conducted to compare the difference in WOBp in two assisted modes of ventilation, PCV and VCV with constant flow. Methods : Ten patients with respiratory failure were included in this study. Initially, the patients were placed on VCV with constant flow at low tidal volume($V_{T,\;LOW}$)(6-8 ml/kg) or high tidal volume($V_{T,\;HIGH}$)(10-12 ml/kg). After a 15 minute stabilization period, VCV with constant flow was switched to PCV and pressure was adjusted to maintain the same tidal volume($V_T$) received on VCV. Other ventilator settings were kept constant. Before changing the ventilatory mode, WOBp, $V_T$, minute ventilation($V_E$), respiratory rate(RR), peak airway pressure (Ppeak), peak inspiratory flow rate(PIFR) and pressure-time product(PTP) were measured. Results : The mean $V_E$ and RR were not different between PCV and VCV during the study period. The Ppeak was significantly lower in PCV than in VCV during $V_{T,\;HIGH}$. HIGH ventilation(p<0.05). PIFR was significantly higher in PCV than in VCV at both $V_T$ (p<0.05). During $V_{T,\;LOW}$ ventilation, WOBp and PTP in PCV($0.80{\pm}0.37\;J/min$, $164.5{\pm}74.4\;cmH_2O.S$) were significantly lower than in VCV($1.06{\pm}0.39J/mm$, $256.4{\pm}107.5\;cmH_2O.S$)(p<0.05). During $V_{T,\;HIGH}$ ventilation, WOBp and PTP in PCV($0.33{\pm}0.14\;J/min$, $65.7{\pm}26.3\;cmH_2O.S$) were also significantly lower than in VCV($0.40{\pm}0.14\;J/min$, $83.4{\pm}35.1\;cmH_2O.S$)(p<0.05). Conclusion : During assisted ventilation, PCV with decelerating flow was more effective in reducing WOBp than VCV with constant flow. But since individual variability was shown, further studies are needed to confirm these results.

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The Effects of Nitric Oxide and Sphingosine 1-phosphate on the Pulmonary Microstructure in a Rat Model of Acute Lung Injury: An Intravital Videomicroscopic Approach (Nitric Oxide 및 Sphingosine 1-phosphate가 말초 호흡 단위에 미치는 영향의 생체 내 분석: 백서의 급성 폐 손상 모델에서 생체 접촉 현미경을 이용한 연구)

  • Lee, Jae-Ik;Jheon, Sang-Hoon;Sung, Sook-Whan;Kim, Joo-Hyun
    • Journal of Chest Surgery
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    • v.41 no.2
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    • pp.177-188
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    • 2008
  • Background: To evaluate the effects of inhaled nitric oxide (NO) and sphingosine 1-phosphate (S1P) as potential therapeutic agents of acute lung injury, we analyzed the morphology in vivo of the pulmonary microstructure using intravital videomicroscopy in a rat model of acute lung injury. Material and Method: Sprague Dawley rats were divided into five groups: a control group that underwent normal saline aspiration, an acute lung injury (ALI) group that underwent hydrochloric acid aspiration, and three treatment groups that underwent hydrochloric acid aspiration and were administered therapeutic agents- the S1P group, the NO group, and the S1P+NO group (n=7 per group). To quantify alveolar compliance and interstitial edema, the diameters of all measurable alveoli and interalveolar septa were averaged at one and two hours after aspiration. Alveolar compliance was determined according to diameter changes during the respiratory cycle and the change in tidal volume. Result: At two hours after aspiration, the mean alveolar compliance (% change) in the All group decreased significantly versus the control group of rats (respiratory cycle: 1.9% for the ALI group vs 6.5% for the control group, p=0.03; tidal volume: 3.2% for the ALI group vs 9.1% for the control group, p=0.003) and versus the NO group (tidal volume: 3.2% for the ALI group vs 16.9% for the NO group, p=0.001). At two hours after aspiration, the mean interalveolar septal thickness in the NO group tended to be smaller as compared to that in the All group ($15.2{\mu}m$ for the ALI group vs $12.3{\mu}m$ for the NO group, p=0.06). S1P did not exert a significant effect on the pulmonary microstructure of the injured rat lung. Conclusion: Improved alveolar compliance and reduced interstitial edema, observed by intravital videomicroscopy, suggest that inhaled NO ameliorates lung injury.

Geo-surface Environmental Changes and Reclaimed Amount Prediction Using Remote Sensing and Geographic Information System in the Siwha Area (원격탐사와 지리정보시스템을 이용한 시화지구 일대의 지표환경변화와 토공량 예측연구)

  • Yang, So-Yeon;Song, Moo-Young;Hwang, Jeong
    • The Journal of Engineering Geology
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    • v.9 no.2
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    • pp.161-176
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    • 1999
  • The objectives of this study are to analyze the changes of geo-surface topography in the Siwha embankment and the Ahsan city area by the image processing of Landsat Thematic Mapper data, and to estimate the reclaimed amount of the exposed tidal flat in the Siwha area using the GIS. False color composite, Tasseled cap, NVDI(normalized difference vegetation index), and supervised classification techniques were used to analyze the distribution of sediments and the aspect of topographical variations caused by artificial human actions. The total amount of the exposed tidal flat was estimated on the basis of the database snch as aerial photography, hydrographic chart, geological map, and scheme drawing in the Siwha area. The possible excavation regions for a seawall were predicted analyzing the supervised classification image of Landsat TM data. Tasseled cap images were used to observe the distribution of sediments. The difference of the NDVI images between spring and summer seasons indicates that deciduous and coniferous forests were distributed over the whole areas. The total fill-volume of the exposed Siwha tidal flat and the fill-volume of the construction planning seawall were calculated as $581,485,354\textrm{m}^3{\;}and{\;}3,387,360\textrm{m}^3$, respectively, from the digital terrain analysis. Daebu Island, Sunkam Island, and the part of Songsan-myeon were chosen as the cut area to make the seawall, and their cut-volumes were estimated as $5,229,576\textrm{m}^3,{\;}79,227,072\textrm{m}^3,{\;}and{\;}47,026,008\textrm{m}^3$, respectively. Therefore, the cut-volume of Daebu Island alone among three areas was sufficient to make the seawall.

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A Study on the Physiological and Psychological Factors related to Successful Weaning from a Mechanical Ventilator (기계환기기 이탈의 성공과 관련된 생리적${\cdot}$심리적 요인에 관한 조사 연구)

  • Kim, Cho-Ja;Kim, Hwa-Soon;Jang, Yeon-Soo;Kim, Eun-Sung
    • Journal of Korean Academy of Nursing
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    • v.30 no.4
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    • pp.995-1005
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    • 2000
  • This study was performed to identify the physiological and psychological variables related to successful weaning from a mechanical ventilator. The subjects of this study were 22 patients who received mechanical ventilation therapy for more than 3 days in intensive care units. Before the weaning trial, baseline data for following physiologic variables were obtained: spontaneous respiration rate, blood pressure, pulse rate, PaO2, PaCO2, PEEP, static compliance, minute ventilation, tidal volume, rapid shallow breathing index(f/VT), SaO2, PaO2/FiO2 and mean arterial pressure. During spontaneous breathing, physiologic and psychologic variables such as vital signs, ABG, perspiration, chest retraction, paradoxical respiration, dyspnea, anxiety, confidence and efficacy were measured. Successful weaning was defined as sustaining spontaneous respiration over 24 hours after extubation. Weaning failure was defined as the development of more than one of following signs: (1) hypoxemia, (2) CO2 retention or (3) perspiration, tachypnea, chest retraction, tachycardia, arrhythmia, hypotension or hypertension. Subjects (N=18) who successfully weaned from mechanical ventilator were compared with subjects (N=4) who failed. The results are as follows; Eighteen percents of the subjects failed during the weaning trial. Most subjects in the failed group were mechanically ventilated for long-time. This result shows that the success of weaning is more difficult in long-term ventilation patients. In the baseline data that was measured before weaning trial, the mean score of PaO2 in the successfully weaned group was 121mmHg. This is significantly higher than the mean score of PaO2 in the failed group(95mmHg). However, the scores of pH, tidal volume, f/VT, pulse rates, blood pressure, mean airway pressure, SaO2, and PaCO2 were similar between the two groups. Specially the scores of f/VT index as a predominant predictor for successful weaning were not significant (f/VT=44.4) and (f/VT=47). During spontaneous breathing, the scores of dyspnea and anxiety level in the successfully weaned group were less than those of the failed group. On the contrary, the scores of confidence and efficacy in the successful group were greater than those of the failed group. In conclusion, the baseline data that were measured before weaning trial were similar between the both groups, therefore future studies are needed to focus on searching other variables besides physiological parameters related to weaning outcome.

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Clinical Practice Guideline of Acute Respiratory Distress Syndrome

  • Cho, Young-Jae;Moon, Jae Young;Shin, Ein-Soon;Kim, Je Hyeong;Jung, Hoon;Park, So Young;Kim, Ho Cheol;Sim, Yun Su;Rhee, Chin Kook;Lim, Jaemin;Lee, Seok Jeong;Lee, Won-Yeon;Lee, Hyun Jeong;Kwak, Sang Hyun;Kang, Eun Kyeong;Chung, Kyung Soo;Choi, Won-Il
    • Tuberculosis and Respiratory Diseases
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    • v.79 no.4
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    • pp.214-233
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    • 2016
  • There is no well-stated practical guideline for mechanically ventilated patients with or without acute respiratory distress syndrome (ARDS). We generate strong (1) and weak (2) grade of recommendations based on high (A), moderate (B) and low (C) grade in the quality of evidence. In patients with ARDS, we recommend low tidal volume ventilation (1A) and prone position if it is not contraindicated (1B) to reduce their mortality. However, we did not support high-frequency oscillatory ventilation (1B) and inhaled nitric oxide (1A) as a standard treatment. We also suggest high positive end-expiratory pressure (2B), extracorporeal membrane oxygenation as a rescue therapy (2C), and neuromuscular blockage for 48 hours after starting mechanical ventilation (2B). The application of recruitment maneuver may reduce mortality (2B), however, the use of systemic steroids cannot reduce mortality (2B). In mechanically ventilated patients, we recommend light sedation (1B) and low tidal volume even without ARDS (1B) and suggest lung protective ventilation strategy during the operation to lower the incidence of lung complications including ARDS (2B). Early tracheostomy in mechanically ventilated patients can be performed only in limited patients (2A). In conclusion, of 12 recommendations, nine were in the management of ARDS, and three for mechanically ventilated patients.

Long-Period Sea Level Variations around Korea, Japan, and Russia (우리나라 근해의 장기적인 해수면변화)

  • PANG Ig-Chan;OH Im-Sang
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.6
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    • pp.733-753
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    • 1994
  • Monthly mean sea levels from 103 tidal stations in Korea, Japan, and Russia are analyzed to study long-period sea level variations. Barometric adjustment are done for all the sea level data, using monthly air pressures at sea levels from meteorological stations near tidal stations. Seasonal variation is dominant in most of study area. It is the largest in the coasts along the Tsushima Current, and the smallest in the Russian coasts. The cross-correlations of seasonal variations are very high between the coasts along the Tsushima Current. In these marginal seas, seasonal variations seem to be related with the Tsushima Current. The phase of seasonal variations is generally getting late from south to north, and also from west to east. On the other hand, longer-period variations(longer than seasonal variation) have the largest amplitudes and the earliest phases in the coasts along the Pacific Ocean, which shows that they propagate from the Pacific Ocean. Shorter-period variations (shorter than seasonal variation) have generally lower cross correlations. Their values do not show any dictinct difference between areas, and show a common tendency that they are inversely proportional to distance. It implies that the shorter period waves are generated all over the study areas, and propagate in all the directions with faster dissipations. The trends of sea levels in the study area are generally negative in the coasts along the Pacific Ocean and positive in the other areas during the period of 1965 to 1985. By the trends, the mean volume transport between Cheju and Sasebo can be reduced by about 1 Sv during the period. The seasonal variation of volume transport obtained by sea level difference is about 2 Sv in the Korea Strait. The values are comparable to previous reports.

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A Rough Estimation of Environmental Capacity in the Yellow Sea using a Numerical Hydrodynamic Model (해수운동모델을 이용한 황해 환경용량의 개략 산정)

  • Kim Gwang Su;Kim Dong Myung;Park Chung Kil
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.2 no.1
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    • pp.63-73
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    • 1999
  • The results of residual currents simulation by a three-dimensional hydrodynamic model showed the water volume transport and the residence time to be about 4km³ per tidal cycle and about 6 years through the line of latitude, 34° 25' N in the Yellow Sea, and to be about 13km³ per tidal cycle and about 2.5 years through the southeastern boundary line of the Yellow Sea, respectively. On the bases of the entire seawater volume of the Yellow Sea and dissolved oxygen (DO) in summer, the environmental capacity of the Yellow Sea for reception of the maximum pollution load without reducing DO concentration below 5.0mg/ℓ in seawater may be estimated to be about 58×10/sup 6/tons of chemical oxygen demand (COD), which is equivalent to the load about 8 times as high as the annual organic pollution load from 14 major rivers. On the bases of DO transports by residual currents calculated on the line of 34° 25' N latitude and on the southeastern boundary line of the Yellow Sea being about 57×10³tons and about 203×10³tons of DO per day, respectively, the environmental capacities of the Yellow Sea for reception of the maximum pollution loads without reducing DO concentration in seawater nay be equivalent to COD loads about 3 times and 10 times, respectively, as high as the existing organic pollution loads from 14 major rivers.

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Evaluation of Dispersant Application to Stranded Oil as a Clean-up Technique at Sandy Tidal Flat (사질 조간대 표착유의 방제를 위한 유화분산제의 적용 평가)

  • Cheong, Cheong-Jo
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.11 no.4
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    • pp.227-231
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    • 2008
  • The purpose of this study is to clarify the behavior of stranded crude oil and to estimate the restoration of seawater infiltration by application of dispersant as one of cleaning techniques. We made visualization of infiltration process of seawater and stranded crude oil on the sandy beach sediments by using of a model sandy beach. Major conclusions derived from this study are as follows. The seawater infiltration volume was reduced by the stranded crude oil. However, thirty percentage of the sweater infiltration into the sediments was restored by dispersant application to the penetrated oil in sandy beach. The penetration depth of stranded oil were dropped at first falling tide, but were not significantly fluctuated after that. Moreover, oil concentration was most high within the upper 2 cm. The stranded crude oil was broken into small size droplets and dispersed into the sediments by the dispersant application. Therefore, dispersant applications play an important roles in the large increase of surface area of given volume of oil, and it resulted in promoting to biological degradation process at the oil/water interface, dispersing the stranded oil into the water column and restoration of the supplement of the dissolved oxygen and nutrients to the benthic organisms.

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