The effect of COVID-19 pandemic on the length of stay and outcomes in the emergency department

Objective@#This study aimed to evaluate the change in length of stay (LOS) in the emergency department (ED) and outcomes during the coronavirus disease 2019 (COVID-19) pandemic. @*Methods@#This is a single-center, retrospective observational study. We compared ED LOS and outcomes in patients aged ≥19 years who presented to the ED of Soonchunhyang University Bucheon Hospital, a single tertiary university hospital, between January and December in 2018, 2019, and 2020. We included patients who were diagnosed with fever, pneumonia, and sepsis in the ED, based on the International Statistical Classification of Diseases and Related Health Problems 10th Revision. We also compared the LOS and outcomes of overall ED patients in 2019 (before COVID-19) and in 2020 (after COVID-19). @*Results@#A total of 5,061 patients with fever, pneumonia, and sepsis were analyzed. The LOS in the ED in 2020 significantly increased compared with 2018 and 2019 (177.0±115.0 minutes in 2018, 154.0±85.0 minutes in 2019, and 208.0±239.0 minutes in 2020). The proportion of patients who were transferred to other hospitals in 2020 (2.1%) increased compared with 2018 (0.8%) and 2019 (0.7%). Intensive care unit admission significantly increased in 2020 (13.7%) compared with 2019 (10.3%). Among all ED patients, ED LOS in 2020 was longer than in 2019, particularly in patients who were admitted and then transferred to another hospital. Intensive care unit admission (4.4% vs. 5.0%), transfer rate (0.7% vs. 0.9%), and ED mortality (0.6% vs. 0.7%) also significantly increased. @*Conclusion@#The ED LOS, time to intensive care unit admissions, time to transfer to other hospitals, and ED mortality significantly increased during the COVID-19 pandemic.

Emergency medicine residents’ needs assessment for education and training using nationwide survey

Objective@#This study was conducted to identify the needs assessment for education and training of emergency medicine (EM) residents. @*Methods@#The results of a national survey of EM residents of the Korean Society of Emergency Medicine in 2019 were used. Education was one of the five categories in the survey. The preferred learning methods and their perceived importance and ability to perform in nine competencies were assessed. The Borich’s needs assessment model was used to analyze their needs. @*Results@#Among 591 EM residents, 382 responded, and 371 responses were finally analyzed. Regarding the learning methods, junior residents preferred in-hospital conferences, staff lectures, internet resources, and textbooks. Overall, medical knowledge and procedural skills were the most important, and research was less important to recognize. Medical knowledge showed the highest rank in the needs assessment in all years, and ethics and professionalism showed the lowest ranks. The needs for procedural skills were higher in junior years but lower in senior years. @*Conclusion@#These results will form the basis for the design of training programs to meet the educational needs of EM residents for each grade. Furthermore, an analysis of the educational needs should be done periodically according to the changes and demands of the times.

How many emergency medicine residents reselect their specialty if they could?

Objective@#The 2019 Korean Emergency Medicine Residents Survey (KEMRS) is the first survey by the Korean Society of Emergency Medicine (KSEM) on the comprehensive satisfaction of their residents. Satisfaction is important not only for the personal well-being of the residents but also for patient safety. @*Methods@#A total of 622 emergency medicine residents were surveyed, using both a paper and email questionnaire from May to August of 2019. Factors related to satisfaction were analyzed. @*Results@#Of the responders, 66% said they would reapply for the emergency specialty and 51% said that they would reselect the same training hospital. The group of residents who said they would choose emergency medicine again felt that their expectations had been met and that they were comfortable with the choice of the specialty. They felt that the factors of satisfaction with their shift schedule and personal health played a more important role in their reselection of the training hospital than the workload. @*Conclusion@#The satisfaction levels of the Korean emergency residents were low. Thus, training hospitals should provide a reasonable working environment to increase their satisfaction. Also, it is important to create an environment where residents can feel rewarded and proud of the work they do.

Comparison of the characteristics and injury severity of passengers in motor vehicle accidents between urban and rural cities in South Korea

Objective@#To analyze motor vehicle accidents in two different traffic environments and compare differences in severity between both regions. @*Methods@#Injury data were collected by the Emergency Medicine and Traffic Accident Research Team as part of the Korean In-Depth Accident Study. Patients admitted to emergency medical centers located in Wonju, Gangwon province (population 345,143, rural, group A) and Bucheon, Gyeonggi province (population 870,735, urban, group B) between January 2011 and December 2017 were included for analysis. Injury severity was classified into four categories based on Injury Severity Score (ISS): minor (1≤ <9), moderate (9≤ <15), major (15≤ <25), and critical (≥25). @*Results@#Overall, 1,807 patients were included (group A, 1,484; group B, 323). There was a higher proportion of daytime accidents, accidents involving larger cars, passenger injuries, and accidents involving lack of seat belt use in group A than in group B. The mean ISS value was 8.98 in group A and 4.62 in group B (P<0.001). Minor (20.4% vs. 10.8%) and major/critical (15.7% vs. 5.0%) injuries were more frequent in group A than group B (P<0.001). Patient ratios (A/B) for each ISS classification were 0.76 (minor), 1.89 (moderate), 3.43 (major), and 2.77 (critical). The factors showing a significant relationship with severity were driver’s seat (P=0.037) and no seat belt (P<0.001). @*Conclusion@#Patients in a rural city who visited the emergency room owing to motor vehicle accidents had more severe injuries than those in an urban city.

How many emergency medicine residents reselect their specialty if they could?

Objective@#The 2019 Korean Emergency Medicine Residents Survey (KEMRS) is the first survey by the Korean Society of Emergency Medicine (KSEM) on the comprehensive satisfaction of their residents. Satisfaction is important not only for the personal well-being of the residents but also for patient safety. @*Methods@#A total of 622 emergency medicine residents were surveyed, using both a paper and email questionnaire from May to August of 2019. Factors related to satisfaction were analyzed. @*Results@#Of the responders, 66% said they would reapply for the emergency specialty and 51% said that they would reselect the same training hospital. The group of residents who said they would choose emergency medicine again felt that their expectations had been met and that they were comfortable with the choice of the specialty. They felt that the factors of satisfaction with their shift schedule and personal health played a more important role in their reselection of the training hospital than the workload. @*Conclusion@#The satisfaction levels of the Korean emergency residents were low. Thus, training hospitals should provide a reasonable working environment to increase their satisfaction. Also, it is important to create an environment where residents can feel rewarded and proud of the work they do.

Simulation of healthcare provider's safety on emergency transportation using advanced airway: extension tube usage or not

OBJECTIVE: Healthcare providers are exposed to risky environments during prehospital transportation when they give O₂ supply to patients. This study examined the problems with risky environments during prehospital transportation and suggests safe and efficient O₂ supply methods through extension tube simulation. METHODS: Fifty-seven volunteers participated the study. The volunteer's back angle was measured during transportation simulation. This study measured the grip strength difference and forearm circumference difference in two situations. Without an extension tube and with extension tube, the participants measured the grip strength and forearm circumference before and after giving an O₂ supply to the mannequin for 5 minutes. The participants replied which body part showed the most discomfort. RESULTS: In the without extension tube group, participants leaned forward on average. On the other hand, the mean of anterior angle was 0° with an extension tube group. Without an extension tube, the grip strength decreased by whereas it decreased by with an extension tube. The decrease in grip strength was similar in both groups (P<0.05), and there was no significant difference in the forearm circumference. With the extension tube, 43.9% of participants reported no discomfort when they gave an O₂ supply. CONCLUSION: The extension tube improved the healthcare provider's safety and O₂ supply convenience during pre-hospital transportation.

Improvement of Waste Drug Management System by Comparing Domestic and Overseas Programs

BACKGROUND@#At the end of the‘Waste Drug Disposal Project’, collection and disposal of waste drugs remain a social issue.@*OBJECTIVE@#This study aimed to provide suggestions to improve the drug waste management system in Korea by comparing domestic and overseas relevant programs. Methods: This is a comparative study between South Korea, Australia, Canada, France, and the US. These overseas countries were selected because they have been operating waste drug management programs continuously to date. Comparison was conducted by a pre-determined analysis frame including legal regulation, enforcement program and its performance.@*RESULTS@#All selected countries except Australia had legal regulations on drug wastes. The US had the largest variety of drug waste disposal methods. Canada had recommended that pharmacies actively participate in drug waste withdrawal programs. France had the largest variety of methods to promote relevant programs, including window sticker, SNS, and app, as well as the highest level of awareness and participation. Australia had the lowest level of awareness and participation in pharmaceutical waste management programs. Pharmaceutical companies took responsibility of paying for these programs in the selected overseas countries.@*CONCLUSION@#Further efforts should be made to establish a clear guideline including the role of pharmaceutical companies, and to develop various methods for the public to be aware of appropriate ways of disposing drug wastes in Korea.

Visual Analysis of Regional Variations in Antidepressant Use and Suicide Rate

BACKGROUND: Some mental illnesses such as depression are known to be one of the risk factors of suicide and proper antidepressant therapy can reduce suicidal behavior. OBJECTIVES: This study aimed to analyze regional variations in antidepressant consumption and adherence, suicide rate, prevalence of suicide related mental disorders, and access to relevant healthcare services. METHODS: Cross-sectional analyses were conducted using National Patients Sample data compiled by the Health Insurance Review and Assessment Service between 2014 and 2016. We included patients who had a diagnosis record of suicide related mental disorders during the study period. Cause of death statistics and National health and medical statistics were used to identify suicide rate and distribution of healthcare service. We conducted visual analyses, chi-squared tests, independent t-tests and correlation analyses to demonstrate regional variations. RESULTS: Between 2014 and 2016, the average prevalence of suicide related mental disorders was 5.4 per cent. Suicide rate and prevalence of suicide related mental disorders were higher in Gangwon, Chungcheong, and Jeolla (p < 0.001), and lower in Seoul (p < 0.001) than the national average. Unexpectedly, regional variations in antidepressant consumption were seen in the limited area including Daejeon, Chungnam and Gyeongnam (p < 0.05). The number of mild patient-centered clinics was associated positively with antidepressant consumption (p < 0.01) and associated negatively with suicide rate (p < 0.01). CONCLUSION: There were some regional variations in prevalence of suicide related mental disorders, antidepressant adherence and suicide rate. The higher level of antidepressant therapy and the lower level of suicide rates were seen in regions with easy access to mild patient-centered clinics.

Comparison with in-hospital Korean Triage and Acuity Scale (KTAS) and prehospital triage system in a metropolitan city

OBJECTIVE: This study was conducted to analyze and compare the classifications of a prehospital triage system and an in-hospital triage system. METHODS: The records of patients transferred from the ‘119’ emergency service for 5 months (from January 1 to May 31, 2016) were collected and records of first aid activities were assessed. We examined cases classified as four (urgent, semi-urgent, potentially urgent, and non-urgent) of five stages, excluding death. In the hospital, data were collected from medical records and classifications made using the five Korean Triage and Acuity Scale (KTAS) stages (1, resuscitation; 2, emergency; 3, urgent; 4, less urgent; and 5, non-urgent) were analyzed. RESULTS: The number of patients enrolled in the study was 3,457. Of them, 2,301 were discharged after treatment and 1,156 were hospitalized. According to the prehospital triage classification, 726 of the 3,457 cases were urgent, 593 were semiurgent, 1,944 were potentially urgent, and 194 were non-urgent. The results of the in-hospital triage were as follows: 114 KTAS 1 (3.3%), 491 KTAS 2 (14.2%), 1,345 KTAS 3 (38.9%), 1,227 KTAS 4 (35.5%), and 280 KTAS 5 (8.1%). The odds ratio trend for hospitalization showed a larger decrease according to in-hospital staging (95% CI, 0.32–0.39) than according to prehospital staging (95% CI, 0.50–0.60). The odds ratio trend for intensive care unit (ICU) admission also showed a larger decrease according to in-hospital staging (95% CI, 0.16–0.22) than according to prehospital staging (95% CI, 0.37–0.48). CONCLUSION: We found little correspondence in classifications made according to the KTAS and prehospital triage systems. However, the tendencies toward decreases in the hospitalization and ICU admission rates were similar.

An analysis of caregivers' preference regarding fever management in the emergency department

PURPOSE: To investigate caregivers' preference regarding fever management in the emergency department. METHODS: Between July 2011 and June 2014, we surveyed the preference in fever management by caregivers of febrile children aged 7 years or younger who visited the emergency department. The questionnaire consisted of the characteristics of the children and their caregivers, usefulness of tepid massage, and the caregivers' preference in fever management, in particular the combination of methods and the doses of antipyretics. RESULTS: Among a total of 161 children, 161 were enrolled in the study, with the mean age of 5.0 years. Of the caregivers, 64.6% were in their 30s and 50.9% were parents, and 70.2% and 24.2% reported that tepid massage was "very useful" and "a little useful," respectively. The most preferred combination of methods was "tepid massage, acetaminophen, and ibuprofen (50.9%; P < 0.001)." "Tepid massage and ibuprofen" was preferred to "tepid massage and acetaminophen (24.2% vs 7.5%)." The most preferred dose of antipyretics was 1 mL/kg/day (divided into 3 doses; 60.2%; P = 0.012), followed by 1 mL/kg/day (divided into 3 doses) plus 2 mL/dose (29.1%). CONCLUSION: Caregivers may recognize tepid massage as a useful fever management. The most preferred fever management was the combination of tepid massage, acetaminophen, and ibuprofen with a dose of 1 mL/kg/day.

Should Let Them Go? Study on the Emergency Department Discharge of Patients Who Attempted Suicide

OBJECTIVE: The purpose of this study was to analyze the characteristics and factors of voluntary discharged patients after suicide attempt and analyze the effectiveness of follow-up measures. METHODS: Total 504 adult patients aged 14 years and over, who visited a local emergency medical center from September 1, 2013 to December 31, 2015 were enrolled and retrospectively reviewed. We analyzed the relationship with voluntary discharge group (VDG) among basic characteristics, suicidal attempt variables, outcome variables related to suicide attempts, and treatment related variables comparing with normal discharge group (NDG). RESULTS: Of the total 504 suicide attempts, three hundred eleven (61.7%) patients were VDG and 193 (38.2%) were NDG. The proportion of patients who completed the community service linkage were 18.7% (36/193) in NDG, compared with 7.7% (24/311) in VDG (p < 0.05). In addition, the ratio of the patients who visited psychiatric outpatient department in NDG were 57.0% (110/193), more than four times as likely as 14.5% (45/311) in VDG (p < 0.05). CONCLUSION: Over sixty percent of suicide attempters discharged against medical advice. Further various aspects of national supportive measures including strengthening case management service should be considered.

Safety and Efficacy of Tolvaptan in Korean Patients with Hyponatremia Caused by the Syndrome of Inappropriate Antidiuretic Hormone

BACKGROUND: The aim of this multicenter study was to evaluate the safety and efficacy of tolvaptan (TLV) in Korean patients with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). METHODS: Of 51 enrolled patients with SIADH, 39 patients (16 female patients, aged 70.8 ± 11.3 years) were included in an intention to treat analysis. All patients received 15 mg/day as the initial dose, and the dose was then increased up to 60 mg/day (as needed) until day 4. RESULTS: Serum sodium increased significantly from baseline during the first 24 hours (126.8 ± 4.3 vs. 133.7 ± 3.8 mmol/L, P < 0.001), rose gradually between days 1 and 4 (133.7 ± 3.8 vs. 135.6 ± 3.6 mmol/L, P < 0.05), and then plateaued until day 11 (136.7 ± 4.5 mmol/L). The correlation between the change in serum sodium for the first 24 hours and initial serum sodium concentration was significant (r = −0.602, P < 0.001). In severe hyponatremia (< 125 mmol/L), the change was significantly higher (11.1 ± 4.8 mmol/L) than in moderate (6.4 ± 2.5 mmol/L, P < 0.05) or mild hyponatremia (4.3 ± 3.3 mmol/L, P < 0.01). In addition, logistic regression analysis showed that body weight (odds ratio [OR], 0.858; 95% confidence interval [CI], 0.775–0.976; P = 0.020) and body mass index (BMI) (OR, 0.692; 95% CI, 0.500–0.956; P = 0.026) were associated with rapid correction. No serious adverse events were reported, but in 13% of patients hyponatremia was overcorrected. CONCLUSION: TLV is effective in correcting hyponatremia and well-tolerated in Korean patients with SIADH. However, those with low body weight, low BMI or severe hyponatremia, could be vulnerable to overcorrection with the initial dose of 15 mg TLV.

Satisfaction surveys on major subjects in emergency medical system in Korea: joint investigation of the Korean Society of Emergency Medicine and Korean Science Journalists Association

OBJECTIVE: This study was conducted to investigate satisfaction surveys of the emergency medical system in Korea administered to both members of the Korean Society of Emergency Medicine and patients and their guardians. METHODS: The joint survey was conducted by the Korea Scientist Journalists Association and the Public Affairs Committee of the Korean Society of Emergency Medicine. Questionnaires administered to each group included questions about the general environment, safety, and overcrowding. Satisfaction of medical staffs and awareness of cardiopulmonary resuscitation were only included in the patient questionnaire, while public health was only surveyed in the member questionnaire. The satisfaction was evaluated on a 5-point scale. RESULTS: Patient questionnaires were answered by 20 of 413 national emergency medical centers, and about 4.3% of the medical institutions participated in the questionnaire. A total of 704 reply sheets were returned by patients. Member questionnaires were answered by 280 of the 1,108 members (25%). Among patients, the lowest satisfaction was the item of “medical expenses,” followed by “waiting time”. Among providers, the lowest satisfaction was “appropriateness of medical staff”, while the highest complaint was “overcrowding.” CONCLUSION: Emergency care users had the lowest satisfaction with “medical expenses,” while members had the lowest satisfaction with “lack of manpower” and were most dissatisfied with “violence” and “overcrowding.”

Analysis the Change of Recognition and Attitude between Before and After Experience of Emergency Medicine Education Program in Medical School Students

PURPOSE: This study was performed to analyze the results from a 2016 three-day emergency medicine camp for premedical students. METHODS: The Public Relations Committee of Korea Emergency Medical Association planned the camp. We sent an official letter to 41 universities to recruit participants and create programs for three days. Questionnaires were prepared and analyzed before and after the camp. RESULTS: A total of 37 participants participated. There were three times more males than females. According to the recognition survey, knowledge (3.4±2.0 vs. 7.2±1.8) and preference (5.4±1.8 vs. 7.4±1.4) after the camp were better than before the camp (p<0.05). In detail, anxiety about funerals (3.5±2.5 vs. 2.4±2.8) and perception of the role (5.8±2.2 vs. 4.5±2.6) were improved (p<0.05). Worries regarding physical and psychological burden and danger were also greatly improved (p<0.05). The mean satisfaction was 8.6 points out of 10 points, according to the general survey. CONCLUSION: The three-day camp increased awareness of emergency medicine and improved their preferences.

Confirmation of the Relation between Femoral Artery and Vein for Central Venous Cannulation: A Prospective Investigation Using Ultrasound

PURPOSE: Femoral vein catheterization is often performed using a landmark technique, despite the recommended method of using ultrasound guidance. Although the landmark-based procedure is a well-known, widely adopted method to date, there are insufficient studies validating the effectiveness of this method. Hence, the purpose of this study was to confirm the relationship between femoral artery and vein using an ultrasound, as well as to validate the effectiveness of the femoral vein catheterization method using the landmark technique. METHODS: This was a prospective, repeated measurement study. Using an ultrasound with a 10 MHz transducer, the femoral vein cross-sectional areas on the right side were saved at a distance of 1, 2, 3, and 4 cm from the inguinal ligament with supine and hip abduction-external rotation positions. The width of the femoral vessels, center-to-center distance between the femoral artery and vein(horizontal distance between the center of the femoral artery and vein) and width of exposed femoral vein (not posterior to femoral artery) were measured. RESULTS: The width of the femoral vein, the center-to-center distance between the femoral artery and vein, as well as the width of the exposed femoral vein were significantly decreased as the distance from the inguinal ligament was increased, regardless of the posture change (p<0.001). However, at a distance of 1 cm from the inguinal ligament, only 5.4% of the femoral veins were exposed without disturbance of the femoral artery, and there were also a few cases in which the femoral veins were not exposed at all. CONCLUSION: It appears that an ultrasound-guided femoral vein catheterization is recommended over the conventional landmark technique.

Analysis of Prognostic Factors Affecting Admission in Acute Alcohol-intoxicated Patients with Traumatic Brain Injury Visiting Emergency Room

PURPOSE: This study analyzed the prognostic factors affecting admission in acute alcohol-intoxicated traumatic brain injury (TBI) patients visiting the emergency room. METHODS: A multicenter, retrospective observational study was conducted on 821 acute alcohol-intoxicated adult trauma patients, who visited 10 university hospital emergency centers from April to November 2016. The primary outcome was hospital admission. The secondary outcome was in-hospital mortality. RESULTS: One hundred sixty-eight patients diagnosed with acute alcohol-intoxicated TBI were analyzed. The increase in blood alcohol concentration was associated significantly with a mild decrease in admission (adjusted odds ratio, 0.993; 95% confidence interval, 0.989 to 0.998; p=0.01). Moderate to severe TBI patients showed a significant increase in admission compared to mild TBI patients (adjusted odds ratio, 12.449; 95% confidence interval, 3.316 to 46.743; p < 0.001). CONCLUSION: This study showed that the admission was inversely correlated with the blood alcohol concentration and is correlated directly with the increase in the severity in TBI. Therefore, emergency physicians may be required to identify the severity of TBI rapidly and accurately in acute alcohol-intoxicated trauma patients visiting the emergency room.

Considerations for physicians using ketamine for sedation of children in emergency departments

OBJECTIVE: Ketamine use in emergency departments (EDs) for procedural sedation and analgesia is becoming increasingly common. However, few studies have examined patient factors related to adverse events associated with ketamine. This study investigated factors for consideration when using ketamine to sedate pediatric ED patients. METHODS: The study included pediatric patients receiving ketamine for laceration repair in the ED. Before sedation, information was collected about upper respiratory tract infection symptoms, allergy history, and fasting time. Patients received 2 mg/kg ketamine intravenously or 4 mg/kg ketamine intramuscularly. The primary outcomes were adverse events due to ketamine. RESULTS: We studied 116 patients aged 8 months to 7 years (2.8±1.5 years). The group with adverse events was significantly younger on average than the group without adverse events (2.5±1.5 vs. 3.1±1.5, P=0.028). Upper respiratory tract infection symptoms were not significant variables affecting ketamine sedation (48.9% vs. 43.7%, P=0.719). There was no significant association between duration of fasting and adverse events (P=0.073 and P=0.897, respectively), or between food type and adverse events (P=0.734). However, the number of attempts to sedate and ketamine dose correlated with adverse events (P<0.001 and P=0.022, respectively). In multiple logistic regression analysis, intravenous injection and ketamine dose were significant factors (odds ratio, 16.77; 95% confidence interval, 1.78 to 498.54; odds ratio, 4.37; 95% confidence interval, 1.59 to 22.9, respectively). CONCLUSION: Emergency medicine physicians should consider injection type and ketamine dose when using ketamine sedation while suturing lacerations.

Does hypokalemia contribute to acute kidney injury in chronic laxative abuse?

Prolonged hypokalemia from chronic laxative abuse is recognized as the cause of chronic tubulointerstitial disease, known as "hypokalemic nephropathy," but it is not clear whether it contributes to acute kidney injury (AKI). A 42-year-old woman with a history of chronic kidney disease as a result of chronic laxative abuse from a purging type of anorexia nervosa (AN-P), developed an anuric AKI requiring hemodialysis and a mild AKI 2 months later. Both episodes of AKI involved severe to moderate hypokalemia (1.2 and 2.7 mmol/L, respectively), volume depletion, and mild rhabdomyolysis. The histologic findings of the first AKI revealed the remnants of acute tubular necrosis with advanced chronic tubulointerstitial nephritis and ischemic glomerular injury. Along with these observations, the intertwined relationship among precipitants of recurrent AKI in AN-P is discussed, and then we postulate a contributory role of hypokalemia involved in the pathophysiology of the renal ischemia-induced AKI.

Current Duty Hours of Emergency Resident Physicians in Korea: Multicenter Cross-sectional Study

PURPOSE: This study was conducted in order to determine the current status of duty hours of emergency resident physicians in Korea. METHODS: The training committee of the Korean Society of Emergency Medicine surveyed using a questionnaire on resident training status, which contained the total number of duty hours during four weeks of July (first to 28th day) according to the grades of the resident physician. The proportions of both irregular working hours and independent working hours without supervision of a board certified physician were also evaluated. RESULTS: Responses from 80 hospitals out of 97 training hospitals were analyzed. The average number of duty hours of emergency resident physicians was 63.7+/-10.7 hours/week. The proportion of hospitals for which the average number of duty hours exceeded 80 hours/week was 16.1%. Irregular working hours consisted of 63.9%. Residents in 15(18.7%) hospitals worked 3.7~73.5% of their duty hours without supervision of a board certified physician. The higher grade resident had fewer working hours (p<0.001). No statistical difference was observed in the rate of both irregular work and unsupervised work according to the grade. CONCLUSION: Results of this study showed that nine(11.3%) hospitals had average duty hours above 80 hours/week. In Korea, training hospitals should prepare to minimize the impact of duty hour restriction in the near future, as well as to improve training quality.

Effectiveness of Polydeoxyribonucleotide (PDRN) Material on Murine Subcutaneous Laceration Wounds

PURPOSE: To evaluate the effectiveness of polydeoxyribonucleotide (PDRN) material on murine subcutaneous laceration wounds. METHODS: Subcutaneous laceration wounds were made on the back of mice. The mice were divided into two groups according to method of PDRN applied: Group I (control, general dressing, and management) and Group II (PDRN injection). We evaluated gross findings and histological findings for the groups. RESULTS: A total of 18 mice (9 in the Suture group and 9 with Suture+PDRN) were enrolled. In the mean results of gross finding (5-point Likert scale), the mean gross findings for wounds in the PDRN group were significantly higher than the suture groups on post-operative day 4 and 7 (for day 4, Suture: 2, Suture+PDRN: 3.2; for day 7, Suture: 2.7, Suture+PDRN: 4.2; p<0.05). In the histological analysis of wounds in the Suture+PDRN group after 10 days, re-epithelization and granulation tissue formation were better than the Suture group. In terms of wound-healing grade, re-epithelization and inflammation were not different; however, in the Suture+PDRN group, more granulation tissue formation was noted compared to the Suture group (p<0.05). In addition, the expression of VEGF in the Suture+PDRN group significantly increased compared to the Suture group (Suture: 11170+/-2475, Suture + PDRN: 27243+/-6621, p<0.05). CONCLUSION: The Suture+PDRN group can be used for the early treatment and histological healing of subcutaneous laceration wounds.