Critical Pathway Implementation for Minor Motor Vehicle Trauma Patients

홍종근,황성연,이영환,성애진,이준호,조광원,신지미 대한응급의학회 2011 大韓應急醫學會誌 Vol.22 No.5

Purpose: The high rate of road traffic crashes and rising medical costs are critical health care problems in Korea as well as in the United States. To reduce the medical cost of minor traffic accidents, we hypothesized that implementation of a 7-day critical pathway (CP) for minor car accident patients (MCP) would decrease medical costs and hospitalization time without lowering patient satisfaction level. Methods: A pretest-posttest experimental design was used to verify the effects of CP on MCP, from June 1 to December 31, 2010. A 7-day admission schedule with daily predefined order communication system (OCS) order set was implementated for MCP. On the day of discharge,MCP completed a satisfaction survey, and the total medical cost and cost per day were calculated. Satisfaction with physician and nursing care were also surveyed using the Brief Encounter Psycho-Social Instrument-Korea tool. Results: Overall rating did not differ in patients processed normally and using the CP, but length of admission was reduced in CP patients. Total medical costs were not different in either group but cost per day was higher in the CP group. Satisfaction with physicians, but not nurses, satisfaction was improved after CP implementation. Conclusion: A critical pathway for MCP reduces length of admission without decreasing patient satisfaction. Total medical costs are not changed after CP implementation but cost per day is significantly increased. Improved job satisfaction in physician but not for nurses was observed after CP implementation. It seems that CP is a effective tool for MCP.

금속재료의 저주기 피로특성을 이용한 피로균열 전파속도의 예측 ( Prediction of Fatigue Crack Propagation Rate Based on Low Cycle Fatigue Characteristics of Metals )

홍종근,강성수,배재현,김정규 대한기계학회 1996 대한기계학회 춘추학술대회 Vol.- No.-

한국인 3차원 인체형상모델을 이용한 고리뼈의 성별판별 검증

홍종근(Chong-Kun Hong),정재광(Jae-Kwang Chung),이우영(U-Young Lee),김덕수(Duk-Soo Kim),박대균(Dae-Kyoon Park),박경호(Kyung-Ho Park) 대한체질인류학회 2014 해부·생물인류학 (Anat Biol Anthropol) Vol.27 No.4

사망 당시의 정보를 알고 있는 마른뼈들을 통계학적으로 분석한 연구가 있다면 마른뼈를 법의인류학적으로 분석하여 개인식별항목(biological profile)을 추정하는 것이 가능하다. 한국인의 경우 개인식별항목을 추정하는 데 필요한 뼈표본이 거의 없기 때문에 개인식별항목을 추정하기 위한 통계학적 자료가 부족하다. 그러므로 뼈대에 붙어 있는 물렁조직을 모두 제거하여 뼈표본을 제작하는 방법의 대안으로 방사선으로 촬영된 진단영상을 활용하여 뼈대를 3차원으로 재구성하는 연구가 제안되고 있다. 이 연구는 해부용 시신을 컴퓨터단층촬영(computed tomography)하여 구축한 3차원 인체형상모델에서 뼈대 정보를 재구성하여 계측하였고, 통계학적 분석을 통해 성별을 추정하는 데 도움이 되는지를 조사하였다. 가톨릭대학교 가톨릭응용해부연구소에서 관리하고 있는 디지털 코리언(Digital Korean) 데이터베이스에서 고리뼈 (atlas) 100개 (남성 51개, 여성 49개)를 계측하였다. 3차원 컴퓨터 프로그램인 미믹스 (Mimics, Simulation module, Version 13.0, Materialise NV, Belgium)를 이용하여 계측항목들을 계측하였고, IBM® SPSS® (version 20.0, Armonk, New York)를 이용하여 통계학적 분석을 하였다. 계측 결과를 실제 마른뼈의 연구에서 얻은 판별함수를 적용하였을 때 정확도가 떨어졌기 때문에 새롭게 판별함수를 구하였고, 19개 계측항목들 중에서 고리뼈너비(Width of Atlas)가 성별을 추정하는 데 가장 유용한 계측 항목이었다. 본 연구 결과 고리뼈너비가 76.7mm보다 큰 값일 경우 남성으로 판별할 수 있었다. 뼈표본이 부족한 현실에서 한국인 뼈대의 체질인류학적 특징을 연구하는 것은 한계가 있다. 그러므로 방사선 진단영상에서 3차원으로 재구성한 뼈대를 활용하여 형태학적 특징을 규명하려고 시도된 이번 연구의 결과는 디지털 코리언 데이터베이스를 활용하여 체질인류학적 연구를 할 수 있는 가능성을 보여주었다고 생각되고 현장에서도 계측값을 통해 성별을 추정하는 데 도움이 될 것으로 판단된다. Estimation of biological profile for skeletal remains by forensic anthropological examination would be possible based on physical anthropological studies which were statistically analyzed. However, physical anthropological studies for Korean population are not enough to establish biological profile for Korean because there is lack of documented osteological specimens in Korea. Recent study suggested that physical anthropological examination could be possible on the three dimensional data which were reconstructed from computed tomography, instead of preparing skeletal specimen by defleshing bone. One of the aim of this study is to evaluate Digital Korean database which were composed of computed tomographic images of 100 cadavers. The other is to perform statistical analysis on morphometrics for segmented atlas whether the results could be helpful to estimate sex in Korean. We measured 100 segmentation atlases (male 51, female 49) from the Digital Korean database which were under the control of Catholic Institute for Applied Anatomy, The Catholic University of Korea. Measurements of segmented atlas were carried out by using Mimics software (Simulation module, Version 13.0, Materialise NV, Belgium), and values of measurement were performed statistical analysis by IBM® SPSS® (version 20.0, Armonk, New York). Among 19 measurements, the width of atlas showed most crucial element for estimating sex, which was consistent with the result using dried bones of atlas and hit ratio of discriminant functions was 88.0%. 76.7 was the cut-off score of discriminant functions. This results showed that morphometrics for segmented atlas could be helpful in estimating sex using the Digital Korean database. In the future, we expect that the other researchers could more actively use the Digital Korean database as a good specimen for physical and forensic anthropological study.

일개 응급센터에서 급속가압수액주입기의 사용경험

홍종근 ( Chong Kun Hong ),송형곤 ( Hyoung Gon Song ) 대한외상학회 2006 大韓外傷學會誌 Vol.19 No.1

Purpose: Hypovolemia is not uncommon among trauma patients in the emergency department (ED). Successful resuscitation of a hypovolemic patient often requires rapid intravenous administration of massive amounts of fluid. A rapid fluid infuser is used in the ED for this purpose, there have been no studies of their clinical uses and effectiveness. We studied clinical experience with a rapid fluid infuser at an urban university hospital in Seoul, Korea. Methods: We reviewed the medical records of 38 patients admitted to the ED with a history of application of a rapid fluid infuser from January 2004 to July 2005. Adult trauma patients older than 15 years of age were included in this study. Clinical data on the patients and the volume of fluid used to achieve a stable blood pressure were extracted from their medical records. Results: The total number of adult trauma patients with a history of application of a rapid fluid infuser from January 2004 to July 2005 in the ED was 16. The mean systolic blood pressure for deciding to apply the rapid fluid infuser was 74.9±12.7 mmHg. The mean time and volume used to achieve a stable blood pressure were 40.4 min and 2947.3±1339.2 ml, respectively. In all patients, the amount of fluid infused before using the rapid fluid infuser was between 500 ml and 10,000 ml, compared to 1,000 ml and 6,200 ml with the rapid fluid infuser. The mean amount of fluid per min. via the rapid fluid infuser was 85.5 ml. Vital signs were stabilized in 11 patients, 6 of the 11 were discharged alive. Conclusion: The mean amount of fluid delivered per min. via the rapid fluid infuser was much less than expected; thus, there should be clinical guidelines on volume resuscitation with a rapid fluid infuser in the ED. In the future, prospective, multicenter, clinical-data collection is needed for a more sophisticated study. (K Korean Soc Traumatol 2006;19:41-46)

농용 회전익기 로터 양력의 현장측정과 CFD 시뮬레이션 비교

홍종근 ( J. G. Hong ),구영모 ( Y. M. Koo ),하이더바샤랏알리 ( B. A. Haider ),손창현 ( C. H. Sohn ) 한국농업기계학회 2017 한국농업기계학회 학술발표논문집 Vol.22 No.2

농용 회전익기의 로터 블레이드는 익형의 설계를 통하여 양력을 향상시킬 수 있다(Koo, 2012). 본 연구의 목적은 개발된 익형을 장착한 농용 헬리콥터(AGROHELI_4G)의 양력 특성을 자유형 양력시험장치를 이용하여 측정하는데 있어 지면에 앵커된 현장실험 조건을 반영한 CFD 시뮬레이션을 수행하고 현장실험의 결과와 비교하는데 있다. 현장 및 모의실험결과는 제자리 또는 서행조건으로 확장하기 위하여 현장실험과 근사한 조건에서 총양력을 예측하여 검증하였다. 시뮬레이션은 MRF (multiple reference frame) 모델을 채용하여 유동영역을 구성하였으며, 경계층을 wall로 설정한 지면바닥으로부터 블레이드를 0.7R (R: 블레이드 반경)의 높이에 위치시켜 지면효과(ground effect)를 시뮬레이션에 적용하였다. 로터를 둘러싸고 있는 원통 모양의 유동장은 20R로서 정지역(stationary zone)과 운동역(moving zone)으로 구성되어 있고 운동역과의 경계조건은 Interface로 유체의 유입 및 유출이 가능하도록 하였고, 18,000~20,000 iteration 사이에서 양력의 표준편차가 5% 정도까지 수렴하도록 수행하였다. 자유형 양력 시험 장치를 이용하여 현장 측정한 결과 조정간 위치 신호는 피치각과 엔진 스로틀이 연동되어 피치각 5~10도에서 로터의 회전속도는 600~1000 rpm의 범위에서 연동되었다(Koo et al., 2016). 조정간의 신호를 환산한 CPA와 스로틀의 연동으로 결정된 로터 회전속도의 연동에 따른 양력의 비교에서 CPA 8°에서 자중(68 kgf)을 극복하고 유상하중(payload)의 양력을 발휘하기 시작하였다. CPA 10°에서는 유상하중 60 kg을 보이며 총양력 128 kg을 발휘하였다. 실제 현장에서의 CPA의 운용범위는 실속각(stall angle: 약 22°)에 훨씬 못 미치는 각도이며, 본 연구에서 사용된 24.5 kW의 엔진동력은 약 12°의 CPA 이하에서 사용이 제한되었다. 시뮬레이션 결과에서는 CPA 약 8°에서 자중을 극복하고 유상하중(payload)을 발휘하기 시작하였으며, CPA 10°에서의 총양력은 1,266 N으로 유상하중이 61.2 kg로 예측되어 양력 실험치보다 약 2% 높게 예측되었다. CPA 10°에서의 시뮬레이션 세부결과는 양력 1,266 N, 항력 127.2 N, 토크 147.9 N · m, 동력은 15.5kW로 나타났으므로, 현장에서의 유상하중 측정치와 지면효과를 적용한 시뮬레이션의 결과는 2%의 오차에서 일치하였다.

Metronome vs. popular song: A comparison of long-term retention of chest compression skills after layperson training for cardiopulmonary resuscitation

채민석,홍종근,황성연,김영식,하영록,신태용,안정환 대한응급의학회 2015 대한응급의학회 학술대회초록집 Vol.2015 No.2

Introduction: This study compared the long-term retention of chest compression skills after either metronome-guided (MG) or popular song-guided (PG) CPR training. Material & Methods: This was a prospective randomized simulation trial. Untrained laypersons were randomly allocated to MG (n=61) or PG (n=68) groups at CPR training sessions. After CPR training, each participant performed 5-cycle CPR using a manikin with a Skill- ReporterTM immediately and six months after the training. Results: Immediately after training, the mean compression rate (MCR) was slightly higher in the PG than the MG group (107.4 vs. 102.2 min-1; p<0.0001), but there was no significant difference in the proportions of participants with an appropriate chest compression rate (100~120 min-1) (PSACCR) between the MG and PG (53/61 (86.9%) vs. 65/68 (95.6%); p=0.114). Six months later, MCR was faster in the MG than the PG (124.8 vs. 110.0 min-1; p<0.0001), and PSACCR in the PG was higher than that in the MG (62/68 (91.2%) vs. 25/61 (41.0%); p<0.0001). In both tests, there were no significant differences in other chest compression parameters of between the two groups, except for a minimal difference in incomplete chest release. Conclusion: CPR training using a popular song was more effective than metronome-guided training in helping laypersons to maintain recommended compression rates after 6 months.

A Comparison of Compression Rates on the Quality of Cardiopulmonary Resuscitation

홍영훈,홍종근,이경렬,정한호,김정현,김용환,이준호,조광원,황성연 대한응급의학회 2013 大韓應急醫學會誌 Vol.24 No.2

Purpose: In cardiopulmonary resuscitation (CPR) there are different opinions on the compression rate that should be applied. The aim of this study was to compare the total number of adequate compressions delivered during a fiveminute period among four groups of lay persons (≥139min-1, 129-138, 114-128, and <114). Methods: This study represents a secondary data analysis from our previous research about the influence of age on fatigue during CPR. Participants were asked to perform chest compressions (without rescue breaths) at a rate of >100 times/minute and a depth of >5 cm for five minutes. A total of 86 participants were then divided into four groups based on their mean compression rate. Age, sex, and body mass index were analyzed as factors affecting the compression rates. Results: The group delivering a compression rate above 139 compressions min-1 performed better than those delivering below 114 compressions min-1 (p=0.03). There was no significant difference in the mean compression depth (p=0.13), percentage of incomplete chest recoil (p=0.277),or the percentage of incorrect hand positioning (p=0.091). All participants (except five) performed chest compressions at a rate above 100 compressions min-1. EDITOR: It may help to indicate whether age, sex, or body mass index (BMI)had an impact on compression rate. Conclusion: Our results suggest that a chest compression rate above 139 compressions min-1 does not deteriorate the quality of compressions compared to a lower chest compression rate (below 114 min-1) during a five-minute period. Most untrained lay people performed chest compressions well, within a range of 100~150 min-1.

Can clinical scoring systems improve the diagnostic accuracy in patients with suspected adult appendicitis and equivocal preoperative computed tomography findings?

채민석,홍종근,하영록,채민정,김영식,신태용,안정환 대한응급의학회 2017 Clinical and Experimental Emergency Medicine Vol.4 No.4

Objective Adult appendicitis (AA) with equivocal computed tomography (CT) findings remains a diagnostic challenge for physicians. Herein we evaluated the diagnostic performance of several clinical scoring systems in adult patients with suspected appendicitis and equivocal CT findings. Methods We retrospectively evaluated 189 adult patients with equivocal CT findings. Alvarado, Eskelinen, appendicitis inflammatory response, Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA), and adult appendicitis score (AAS) scores were evaluated, receiver operating characteristic analysis was conducted, and the optimal, low, and high cut-off values were determined for patient classification into three groups: low, intermediate, or high. Results In total, 61 patients were included in the appendicitis group and 128 in the non-appendicitis group. There were no significant differences between the area under the curve of the clinical scoring systems in the final diagnosis of AA for equivocal appendicitis on CT (Alvarado, 0.698; Eskelinen, 0.710; appendicitis inflammatory response, 0.668; RIPASA, 0.653; AAS, 0.726). A RIPASA score greater than 7.5 had a high positive predictive value (90.9) and an AAS score less than or equal to 5 had a high negative predictive value (91.7) in the diagnosis of AA. Conclusion The accuracy of clinical scoring systems in the diagnosis of AA with equivocal CT findings was moderate. Therefore, a high RIPASA score may assist in the diagnosis of AA in patients with equivocal CT findings, and a low AAS score may be used as a criterion for patient discharge. Most patients presented with intermediate scores. The patients with equivocal CT findings may be considered as a third diagnostic category of AA.

트랙터 장착형 평두둑 복합기의 작업동력 및 견인특성

구영모,홍종근,한정우,하유신 경상대학교 농업생명과학연구원 2018 농업생명과학연구 Vol.52 No.4

지역 밭작물 생산의 생력화를 제고하기 위하여 개발한 복합 작업기(BG-1200AB)를 트랙터(DK753C:55kW)에 장착하고 평두둑 복합기의 작업동력 및 견인력을 평가하였다. 견인 동력계의 여섯 로드셀에서 측정된 신호는 분력식에 따라 견인력(Ph), 수직력(Pv) 및 수평력(Ps)으로 계산되었고 각축에 생성되는 모멘트(Mh, Mv, Ms)를 계산하여 작업상태를 분석하였다. 견인력은 주로 토양의 다짐상태에 따라 영향을 받으며 평균 108-578kgf의 견인력에 대하여 견인동력은 0.5~0.9kW 정도였다. 작업속도는 0.4~2.0km/h 범위에서 절단피치가 증가할수록 비견인력(specific draft)이 감소하는 감소지수 관계를 보였다. PTO 토크는 경심에 따라 평균 160~350N․m으로 측정되었으며, 로터리 경운과 펌프 구동에 사용되는 PTO동력(9.0~19.8kW)이 소비동력의 대부분을 차지하였다. 따라서 복합기의 운용은 견인 동력효율에 맞춰져서는 이점이 나타나지 않으며 작업결과의 질 즉, 파종상토와 멀칭작업의 품질에 초점이 맞춰져야 한다. 상부견인 또는 하부견인에 따라 부하의 위치와 크기가 변화되고 작업기의 균형이 결정되므로 작업기의 고품질 작업을 추구하기 위하여 하부 링크의 독립적 제어를 제안한다. The integrated tractor implement, developed for saving labor in the production of local upland crop was assessed to determine the operating power and draft using a draft dynamometer and torque meter. Components of draft are measured using six load-cells of the draft dynamometer, and moments of the axises are determined to analyzed operating performance. Draft is influenced mainly by soil compaction, ranging 108-578 kgf and consuming 0.5-0.9 kW of power. With travel speeds of 0.4-2.0 kph, the specific draft is exponentially decaying to the cutting pitch. Therefore, the operation strategy of the integrated attachment should be focused on the quality of seed bed preparating and mulching, rather than the drafting power efficiency. PTO torque is mainly related with tilling depth and measured in the range of 160-350 N․m, resulting in the most of total power consumption in the range of 9.0-19.8 kW power. Depending upon the upper or lower drafts, the draft location is varied and the balance of the attachment is performed. Therefore, the independent control of lower links is necessary to pursue the stable operation of the integrated tractor implement.

응급실 다방문환자의 임상적 특성에 관한 연구 - 응급실 다방문환자의 응급실 과밀화 및 중증도와의 관련성 -

신태건,홍종근,송진우,송형곤 대한응급의학회 2011 대한응급의학회지 Vol.22 No.1

Purpose: Crowding causes dysfunction in the emergency department (ED) and is associated with poor quality of patient care, dissatisfaction of the physicians, and increased financial burden of medical care. Frequent use is often considered a major contributor to ED crowding. The present study sought to verify the relationship between the frequent ED users and ED crowding, and to ascertain the severity of the frequent ED users. Methods: One-year ED visit data from a tertiary teaching hospital located in an urban area were analyzed. Frequent ED users were defined as four or more ED visits per year. Crowding indicators were defined as the length of stay and the percentage of patients staying over 6 hours. Severity indicators were defined as operation within 24 h, admission to intensive care unit, and expiry in the ED. Results: The 2.7% of patients who had four or more ED visits were responsible for 11.9% of visits. The median length of stay of frequent users was significantly longer (6.18 h) than that of infrequent users (3.42 h). The percentage of patients who stayed more than 6 h was significantly larger in the frequent user group than infrequent user group (51.4% vs. 32.9%, respectively; OR=2.158; 95% CI,2.041~2.281). However, the severity of frequent users was lower than that of infrequent users (3.0% vs. 5.3%, respectively;OR=0.553; 95% CI, 0.472~0.648). Conclusion: Frequent users presenting to an ED located in an urban area were more likely to stay longer in the ED,and were less likely to be severe. Active interventions to reduce ED crowding are required.