BACKGROUND AND OBJECTIVES: Although mass transit systems are convenient and efficient for urban people, little attention has been paid to the potential hearing hazard from their noise. The purpose of the current study was to measure and analyze levels of subway interior noise at peak commuter times and to provide information about commuters' daily dose of noise exposure. MATERIALS AND METHODS: To measure the subway interior noise, nine subway lines inside Seoul (i.e., lines 1-9) and six lines surrounding the capital city area (i.e., Central, Bundang, Sinbundang, Incheon, Gyeongui, and Gyeongchun) were chosen. The noise was measured and recorded by a sound level meter for two-hour periods in the morning and evening. RESULTS: 1) In the LZeq analysis, the average noise level of all 15 lines was 72.78 dB; the maximum and minimum noise levels were 78.34 and 62.46 dB, respectively. The average noise level of the nine lines inside Seoul was 73.45 dB, which was 1.68-dB louder than that of the six lines surrounding the capital city area. 2) Based on the LZeq analysis of 33 measured frequencies, 12.5 Hz was the highest frequency and 20,000 Hz was the lowest. 3) There was no remarkable difference in the level of subway interior noise between morning and evening peak commuter times. CONCLUSIONS: We concluded that the level of subway interior noise was not loud enough for commuters to incur noise-induced hearing loss. Regardless, environmental noise control efforts in the subway system might be needed for commuters who take a subway every day.
Hearing ; Hearing Loss, Noise-Induced ; Incheon ; Noise* ; Railroads* ; Seoul

BACKGROUND: All medical conduct should be practiced under the permission of patients or guardians. Because anesthetic procedures have high risk, every anesthesia practice is done under verbal and/or written consent. However, collecting anesthetic permission is not common in Korean medical anesthesiologists. The purpose of this article is to survey current anesthetic status and to provide some suggestions. METHODS: We had given questionnaire sheet to anesthesiologists participating in an annual meeting of the Korean Society of anesthesiologists. It included the percentage of receiving the anesthetic consent, the reasons why they received the informed consent or not, and the conditions to improve to receive it. RESULTS: The total number of responded anesthesiologists was 187. More than half of the responders had received the informed consents from less than 25% of their patients. And only thirty percent of them had taken the consents from more than 75% of their patients. To increase this rate, they replied, it is needed to strengthen the legal validity of the consent and to improve working conditions. CONCLUSIONS: The rate of receiving the informed consent is very low for the anesthesia practice in Korea. There are some procedures that are needed to improve the current situation so that anesthesiologists can provide better quality to the patients.
Anesthesia* ; Humans ; Informed Consent* ; Jurisprudence ; Korea* ; Patient Rights

BACKGROUND: Surgical patients should be provided adequate information on operation. The information on mortality is extremely important among them. The purposes of this study are to investigate the recent mortality associated with anesthesia and surgery, and to get a logistic regression model of mortality based on patient information. METHODS: We collected all of the anesthetic cases except local anesthesia during 5 years (between 2000 and 2004) in a hospital. All deaths within 7 days after anesthesia were retrieved. These data were analyzed in terms of age, gender, department in charge, time point after anesthesia, elective or emergency surgery, type of anesthesia, operation name, and diagnosis. The combined effects of the variables on the mortality were evaluated with logistic regression. The causes of death were also analyzed. RESULTS: There were 155 deaths among 74,458 patients under anesthesia. Age less than 1 year old or greater than 80 years old, male gender, department of thoracic surgery, emergency operation, cardiovascular surgery, and diseases for transplantation had higher mortality than their counterparts. Regression model was followed with assignment of '1' for the above mentioned categories. Other categories were designated by '0'. Log[p (death)/{1-p (death)}] = -9.15+1.03xage+0.66xsex+0.79xdepartment+2.77xemergency+2.52 xdiagnosis+0.89xoperation The leading cause of death was sepsis (21.9%). CONCLUSIONS: The average of mortality within 7 days after anesthesia was 21 per 10,000 anesthetic cases (0.21%). Estimated mortality based on logistic regression ranged from 0.01% to 10.25% depending on patient information.
Aged, 80 and over ; Anesthesia* ; Anesthesia, Local ; Cause of Death ; Diagnosis ; Emergencies ; Hospital Mortality ; Humans ; Logistic Models ; Male ; Mortality* ; Sepsis ; Thoracic Surgery

BACKGOUND: The accuracy of a disposable blood pressure transducer (DBPT) is determined by its physical properties: natural frequency (NF) and damping coefficient (DC). We planned this study to investigate whether the NF and DC of a DBPT are altered by attaching extended catheters and evaluated changes of these physical properties over time. METHODS: Fifteen DBPT sets were connected to a monitor and recorder set. These sets were divided into three groups; five sets had catheters of normal length (Group 1), five sets had 50 cm extended catheters (Group 2), and five sets had 100 cm extended catheters (Group 3). The NF and DC of each system were measured using the fast flush (FF) test. After the DBPT sets were installed, the FF test was performed for each group at five time intervals: 4, 24, 48, 72, and 96 hours. RESULTS: The NF of Groups 2 and 3 decreased and their DC increased compared to those of Group 1. Whereas the NF of Group 3 increased over time, those of Groups 1 and 2 did not. The DC of Groups 2 and 3 decreased over time, but remained unchanged over time for Group 1. When the FF test was done at intervals longer than 24 hours, it was found that the NF, but not the DC, increased for all groups. CONCLUSIONS: Attention should be paid to interpret blood pressure using DBPTs measured by extended catheters and using DBPTs for long periods of time without FFs.
Blood Pressure ; Catheters* ; Transducers ; Transducers, Pressure*

BACKGROUND: The chemical reaction of carbon dioxide absorbent and sevoflurane is known to produce compound A. However, carbon dioxide absorbents are not controlled by the Food and Drug Administration, but are treated as industrial products in some nations. Moreover, carbon dioxide absorbents differ in their capacities to produce compound A, because their chemical compositions differ. In this study, we compared the renal safety between carbon dioxide absorbent products in patients under sevoflurane anesthesia. METHODS: Eighty patients with no preexisting renal disease undergoing elective gynecologic surgery were randomly assigned to receive sevoflurane or isoflurane anesthesia with one of four carbon dioxide absorbent products (Sodasorblime(R), Sodalyme(R), Sodasorb(R), Spherasorb(R)) at the same fresh gas flow of 2 L/min. The renal safety was evaluated by changes of blood urea nitrogen (BUN), creatinine and urine N-acetyl-b-glucoseaminidase (NAG)-creatinine ratio at 24 hours and 72 hours after surgery from preoperative level. RESULTS: There was no significant difference in the renal safety indicators between carbon dioxide absorbents during sevoflurane anesthesia (P > 0.05). However, the BUN and urine NAG-creatinine ratios at 72 hours after surgery were higher in isoflurane anesthesia in some carbon dioxide absorbent groups (P = 0.03 and 0.04, respectively). CONCLUSIONS: We could not find significant differences of renal safety indicators with carbon dioxide absorbents. Although the adverse effect of carbon dioxide absorbents on renal function was not proved, consideration should be given to their contol by the regulation on their efficacy and safety because carbon dioxide absorbents can produce compound A.
Anesthesia ; Anesthetics ; Blood Urea Nitrogen ; Carbon ; Carbon Dioxide ; Creatinine ; Female ; Gynecologic Surgical Procedures ; Humans ; Inhalation ; Isoflurane ; Kidney ; Methyl Ethers ; Pilot Projects ; United States Food and Drug Administration

Presacral ganglioneuromas are extremely rare benign tumors and fewer than 20 cases have been reported in the literature. Ganglioneuromas are difficult to be differentiated preoperatively from tumors such as schwannomas, meningiomas, and neurofibromas with imaging modalities. The retroperitoneal approach for resection of presacral ganglioneuroma was performed for gross total resection of the tumor. Recurrence and malignant transformation of these tumors is rare. Adjuvant chemotherapy or radiation therapy is not indicated because of their benign nature. We report a case of a 47-year-old woman with a presacral ganglioneuroma.
Chemotherapy, Adjuvant ; Female ; Ganglioneuroma* ; Humans ; Meningioma ; Middle Aged ; Neurilemmoma ; Neurofibroma ; Recurrence ; Sacrum*

BACKGROUND: The goal of this study is to develop a general population job-exposure matrix (GPJEM) on asbestos to estimate occupational asbestos exposure levels in the Republic of Korea. METHODS: Three Korean domestic quantitative exposure datasets collected from 1984 to 2008 were used to build the GPJEM. Exposure groups in collected data were reclassified based on the current Korean Standard Industrial Classification (9th edition) and the Korean Standard Classification of Occupations code (6th edition) that is in accordance to international standards. All of the exposure levels were expressed by weighted arithmetic mean (WAM) and minimum and maximum concentrations. RESULTS: Based on the established GPJEM, the 112 exposure groups could be reclassified into 86 industries and 74 occupations. In the 1980s, the highest exposure levels were estimated in “knitting and weaving machine operators” with a WAM concentration of 7.48 fibers/mL (f/mL); in the 1990s, “plastic products production machine operators” with 5.12 f/mL, and in the 2000s “detergents production machine operators” handling talc containing asbestos with 2.45 f/mL. Of the 112 exposure groups, 44 groups had higher WAM concentrations than the Korean occupational exposure limit of 0.1 f/mL. CONCLUSION: The newly constructed GPJEM which is generated from actual domestic quantitative exposure data could be useful in evaluating historical exposure levels to asbestos and could contribute to improved prediction of asbestos-related diseases among Koreans.
Asbestos* ; Classification ; Dataset ; Mesothelioma ; Occupational Exposure ; Occupations* ; Republic of Korea* ; Talc

Background: Research on the status of many chemicals used in the semiconductor industry is needed. The purpose of this study was to describe the overall status of chemical use in the semiconductor industry in Korea and to examine it from a health perspective. Methods: Data on the status of chemical use and safety data sheets at 11 of 12 major semiconductor workplaces in Korea were collected. The number of chemical products and chemical constituents, quantities of chemicals, and trade secret ingredients used, as well as the health hazards were examined. Results: On average, 210 chemical products and 135 chemical constituents were used at the surveyed workplaces. Among all chemical products, 33% (range: 16–56%) contained at least one trade secret ingredient. Most of the trade secret ingredients were used in the photolithography process. Several carcinogens, including sulfuric acid, chromic acid, ethylene oxide, crystalline silica, potassium dichromate, and formaldehyde were also used. Only 29% (39 of 135) of the chemical constituents had occupational exposure limits, and more than 60% had no National Fire Protection Association health, safety, and reactivity ratings. Based on the aforementioned results, this study revealed the following. First, many chemical products and constituents are being used in the semiconductor industry and many products contained trade secret ingredients. Second, many products contained significant amounts of carcinogenic, mutagenic, and reproductive toxicant materials. Conclusion We conclude that protecting workers in the semiconductor industry against harm from chemical substances will be difficult, due to widespread use of trade secret ingredients and a lack of hazard information. The findings of the status of chemical use and the health and safety risks in semiconductor industry will contribute to epidemiological studies, safe workplace, and worker health protection.

Background: Research on the status of many chemicals used in the semiconductor industry is needed. The purpose of this study was to describe the overall status of chemical use in the semiconductor industry in Korea and to examine it from a health perspective. Methods: Data on the status of chemical use and safety data sheets at 11 of 12 major semiconductor workplaces in Korea were collected. The number of chemical products and chemical constituents, quantities of chemicals, and trade secret ingredients used, as well as the health hazards were examined. Results: On average, 210 chemical products and 135 chemical constituents were used at the surveyed workplaces. Among all chemical products, 33% (range: 16–56%) contained at least one trade secret ingredient. Most of the trade secret ingredients were used in the photolithography process. Several carcinogens, including sulfuric acid, chromic acid, ethylene oxide, crystalline silica, potassium dichromate, and formaldehyde were also used. Only 29% (39 of 135) of the chemical constituents had occupational exposure limits, and more than 60% had no National Fire Protection Association health, safety, and reactivity ratings. Based on the aforementioned results, this study revealed the following. First, many chemical products and constituents are being used in the semiconductor industry and many products contained trade secret ingredients. Second, many products contained significant amounts of carcinogenic, mutagenic, and reproductive toxicant materials. Conclusion We conclude that protecting workers in the semiconductor industry against harm from chemical substances will be difficult, due to widespread use of trade secret ingredients and a lack of hazard information. The findings of the status of chemical use and the health and safety risks in semiconductor industry will contribute to epidemiological studies, safe workplace, and worker health protection.

PURPOSE: Increased robotic surgery is attended by increased reports of complications, largely due to limited operative view and lack of tactile sense. These kinds of obstacles, which seldom occur in open surgery, are challenging for beginner surgeons. To enhance robotic surgery safety, we created an augmented reality (AR) model of the organs around the thyroid glands, and tested the AR model applicability in robotic thyroidectomy. METHODS: We created AR images of the thyroid gland, common carotid arteries, trachea, and esophagus using preoperative CT images of a thyroid carcinoma patient. For a preliminary test, we overlaid the AR images on a 3-dimensional printed model at five different angles and evaluated its accuracy using Dice similarity coefficient. We then overlaid the AR images on the real-time operative images during robotic thyroidectomy. RESULTS: The Dice similarity coefficients ranged from 0.984 to 0.9908, and the mean of the five different angles was 0.987. During the entire process of robotic thyroidectomy, the AR images were successfully overlaid on the real-time operative images using manual registration. CONCLUSION: We successfully demonstrated the use of AR on the operative field during robotic thyroidectomy. Although there are currently limitations, the use of AR in robotic surgery will become more practical as the technology advances and may contribute to the enhancement of surgical safety.
Carotid Artery, Common ; Esophagus ; Humans ; Robotic Surgical Procedures ; Surgeons ; Thyroid Gland* ; Thyroid Neoplasms ; Thyroidectomy ; Trachea