PURPOSE: In this study a system dynamics methodology was used to identify correlation and nonlinear feedback structure among factors affecting unplanned extubation (UE) of ICU patients and to construct and verify a simulation model. METHODS: Factors affecting UE were identified through a theoretical background established by reviewing literature and preceding studies and referencing various statistical data. Related variables were decided through verification of content validity by an expert group. A causal loop diagram (CLD) was made based on the variables. Stock & Flow modeling using Vensim PLE Plus Version 6.0b was performed to establish a model for UE. RESULTS: Based on the literature review and expert verification, 18 variables associated with UE were identified and CLD was prepared. From the prepared CLD, a model was developed by converting to the Stock & Flow Diagram. Results of the simulation showed that patient stress, patient in an agitated state, restraint application, patient movability, and individual intensive nursing were variables giving the greatest effect to UE probability. To verify agreement of the UE model with real situations, simulation with 5 cases was performed. Equation check and sensitivity analysis on TIME STEP were executed to validate model integrity. CONCLUSION: Results show that identification of a proper model enables prediction of UE probability. This prediction allows for adjustment of related factors, and provides basic data do develop nursing interventions to decrease UE.
Adult ; Airway Extubation/*psychology ; Female ; Humans ; Intensive Care Units ; Intubation, Intratracheal ; Male ; Middle Aged ; *Models, Theoretical ; Nonlinear Dynamics ; Risk Factors

BACKGROUND: In many studies, oxidative stress markers have been employed to serve as a measure of a disease process or to reflect oxidative status. These oxidative stress markers must have some degree of predictive validity, but full substantiation of this relation is still lacking. This paper presents data on levels of three biomarkers, oxidized low-density lipoproteins (LDL), carbonyl, and 8-hydroxy-2'-deoxyguanosine (8-OHdG), and a number of life style factors associated with oxidative stress in healthy adults. METHODS: For 237 healthy adults aged 40-60 years, a number of life style factors, biochemical characteristics and oxidative status were evaluated. Markers of oxidative stress were measured by an ELISA method. RESULTS: Waist-hip ratio and use of vitamin supplement were associated with serum oxidized LDL (P<0.05). Body mass index and stress had a relationship (P<0.05) with protein carbonyl. Creactive protein was related to serum oxidized LDL (P<0.01). There was no correlation among three oxidative stress markers, oxidized LDL, carbonyl, and 8-OHdG. CONCLUSIONS: The oxidative stress markers used in this study could not be regarded as a general estimate of the healthy individual oxidative status. Further studies focusing on the development of biomarkers to reflect changes in the oxidative status under normal, non-pathological conditions in humans will be required.
Adult ; Biomarkers ; Body Mass Index ; Deoxyguanosine ; Enzyme-Linked Immunosorbent Assay ; Humans ; Life Style* ; Lipoproteins, LDL ; Oxidative Stress* ; Protein Carbonylation ; Vitamins ; Waist-Hip Ratio

PURPOSE: This study was aimed to develop secondary triage rule for decision of interfacility transfer to higher level of trauma center for patients with traumatic brain injury (TBI). METHODS: In a prospective observational study from August 2006 to December 2007 conducted in an urban tertiary emergency department, data were obtained from patients more than 15 years old and with TBI. Primary outcome was defined as meaningful positive CT findings. Secondary outcome was defined as meaningful intervention. Non-adjusted univariated logistic regression model was derived from result of chi-square test and adjusted model was derived using stepwise selection manner. Hosman-Lemeshow test for the goodness of fit was used. RESULTS: Total number of eligible patients with traumatic brain injury was 653. Primary outcome was positive in 103 patients and secondary outcome was positive in 42 patients. In univariate logistic regression, risk factors were age over 65(OR: 2.40), history of cerebrovascular disease(OR: 7.08), fall over two meter(OR: 6.28), pedestrian struck(OR: 18.5), headache(OR: 2.18), vomiting(OR: 3.03), disorientation(OR: 5.37), any evidence of open fracture(OR: 24.03), Glasgow coma sacle less than 13(OR: 4.97), Racoon's eye sign (OR: 2.50). These 10 risk factors were statistically significant in adjusted model which was derived using stepwise selected manner. Hosman-Lemeshow test for the goodness of fit was used and chi-square was 1.307(p=0.86). This decision rule had a sensitivity of 93.48%, a specificity of 41.13%, and a negative predictive value of 97.32%. CONCLUSION: A sensitive clinical decision rule with high negative predictive value for detection of abnormal CT lesions which need transfer to higher level of trauma center was developed.
Brain Injuries ; Coma ; Emergencies ; Eye ; Humans ; Logistic Models ; Prospective Studies ; Risk Factors ; Sensitivity and Specificity ; Trauma Centers ; Triage

PURPOSE: The purpose of this study were to identify the influential factors of bullying of intensive care nurses and to suggest a final structural model based on identified relationships between nursing organizational culture, authentic leadership, self-esteem, and bullying in the workplace. METHODS: Data were collected from 221 nurses at intensive care units in eight general hospitals using structured questionnaires and analyzed by structural equation modeling. RESULTS: In this study, the average of bullying in the workplace was 1.34±0.40, nursing organizational culture was 3.31±0.47, self-esteem was 2.79±0.44, and authentic leadership was 3.61±0.60. The factors affecting nursing organizational culture were authentic leadership (β=.54, p<.001) and self-esteem (β=.24, p=.002) that had direct positive effects on the nursing organizational culture. The nursing organizational culture had also a direct effect on reducing workplace bullying (β=−.45, p<.001). Authentic leadership (β=−.24, p=.004) and self-esteem (β=−.11, p=.004) had indirect effects on workplace bullying, which was mediated by the nursing organizational culture. CONCLUSION To understand and reduce workplace bullying, evaluating a nursing organizational culture should be preceded. Based on the finding of this study, an intervention for increasing authentic leadership and self-esteem of nurses can positively help to create the nursing organizational culture and then reduce workplace bullying.

OBJECTIVES: We have investigated the toxic effects of the inhalation of subchronic and acute levels of n-octane. METHODS: The rats were exposed to n-octane of 0, 2.34, 11.68 and 23.36 mg/L (n = 5 rats/group/gender) in an acute inhalation test (Organization for Economic Co-operation and Development (OECD) TG 403), or to 0, 0.93, 2.62 and 7.48 mg/L (n = 10 rats/group/gender) for a subchronic inhalation test (OECE TG 413), to establish a national chemical management system consistent with the Globally Harmonized Classification System (GHS). RESULTS: Acutely-exposed rats became lethargic but recovered following discontinuation of inhalation. Other clinical symptoms such as change of body weight and autopsy finds were absent. The LC50 for the acute inhalation toxicity of n-octane was determined to exceed 23.36 mg/L and the GHS category was 'not grouping'. Subchronically-treated rats displayed no significant clinical and histopathological differences from untreated controls; also, target organs were affected hematologically, biochemically and pathologically. Therefore, the no observable adverse effect level was indicated as exceeding 7.48 mg/L and the GHS category was 'not grouping' for the specific target organ toxicity upon repeated exposure. CONCLUSION: However, n-octane exposure should be controlled to be below the American Conference of Industrial Hygienists recommendation (300 ppm) to prevent inhalation-related adverse health effects of workers.
Animals ; Autopsy ; Body Weight ; Inhalation ; Octanes ; Rats

PURPOSE: To assess the CT findings of remote metastasis to the gastric cardia in patients with esophageal carcinoma. MATERIALS AND METHODS: Among patients with esophageal carcinomas treated between June 1994 and May 1999, five males aged 65-75 (mean, 67.4) years with histologically proven remote metastasis to the gastric cardia from esophageal squamous cell carcinoma, detected at surgery (n=2) or endoscopic biopsy (n=3), underwent CT scanning. We retrospectively evaluated the findings in terms of the location, size and appearance of each lesion and the presence or absence of associated lymphadenopathy. RESULTS: The primary esophageal carcinomas were located in the middle third (n=4) and lower third (n=1) of the esophagus. All five gastric metastases were solitary and occurred in the gastric cardia, and were separated from the primary tumors. CT showed that the metastases ranged in size from 4.2 to 8.0 (mean, 6.7) cm, and all were larger than the primary tumors. All were ulcerated, and in four cases there was associated abdominal lymphadenopathy. They were all well defined, poorly enhanced, submucosal masses that were endogastric in three cases and exogastric in two. The latter were difficult to differentiate from extrinsic masses compressing the gastric cardia. CONCLUSION: Our results suggest that when a submucosal gastric cardial mass with associated lymphadenopathy is detected by CT during the initial staging or follow-up evaluation of esophageal carcinoma, remote gastric metastasis should be considered.
Biopsy ; Carcinoma, Squamous Cell ; Cardia* ; Esophagus ; Follow-Up Studies ; Humans ; Lymphatic Diseases ; Male ; Neoplasm Metastasis* ; Retrospective Studies ; Tomography, X-Ray Computed ; Ulcer

PURPOSE: We aimed to validate clinical spine clearance criteria for selective pre-hospital spine immobilization and to evaluate the appropriateness, according to those criteria, of spine immobilizations currently being performed in the field. METHODS: This was a 4-month double blind prospective study. Targets were patients with trauma who were transported to a regional emergency center by emergency medical technicians (EMTs). Independent hospital EMTs specified that a spine immobilization was necessary if patients were positive for any of the following 8 criteria: (1) altered mental status, (2) evidence of intoxication, (3) neurological deficit, (4) suspected proximal extremity fracture, (5) cervical pain, (6) cervical tenderness, (7) thoraco/lumbar pain, or (8) thoraco/lumbar tenderness. The appropriateness of the immobilization was evaluated afterward on the basis of the final diagnosis. RESULTS: The study collected data on 171 trauma victims from among 1,135 eligible patients. 10 out of 171 patients (5.1%) received a final diagnosis of spinal fracture or spinal cord injury, and all of them had been assessed according to the criteria as requiring spinal immobilization. Sensitivity, specificity, positive predictive value, and negative predictive value were 100.0%, 44.7%, 10.1%, and 100.0%, respectively. On the other hand, among the 99 patients eventually judged to have required immobilization, 54 patients were not immobilized (54/99 = 54.5%) and were therefore underprotected, and among the 72 patients eventually judged to not require immobilization, 11 were over-protected (11/72 =15.3%). CONCLUSION : Clinical spine clearance criteria were useful both for judging the necessity of pre-hospital spine immobilization and for predicting spinal injuries. If these criteria can be applied to the emergency medical service system of Korea, it will contribute to the performing of appropriate spine immobilization.
Diagnosis ; Emergencies ; Emergency Medical Services ; Emergency Medical Technicians ; Extremities ; Hand ; Humans ; Immobilization* ; Korea ; Neck Pain ; Prospective Studies ; Sensitivity and Specificity ; Spinal Cord Injuries ; Spinal Fractures ; Spinal Injuries ; Spine*

PURPOSE: We aimed to validate clinical spine clearance criteria for selective pre-hospital spine immobilization and to evaluate the appropriateness, according to those criteria, of spine immobilizations currently being performed in the field. METHODS: This was a 4-month double blind prospective study. Targets were patients with trauma who were transported to a regional emergency center by emergency medical technicians (EMTs). Independent hospital EMTs specified that a spine immobilization was necessary if patients were positive for any of the following 8 criteria: (1) altered mental status, (2) evidence of intoxication, (3) neurological deficit, (4) suspected proximal extremity fracture, (5) cervical pain, (6) cervical tenderness, (7) thoraco/lumbar pain, or (8) thoraco/lumbar tenderness. The appropriateness of the immobilization was evaluated afterward on the basis of the final diagnosis. RESULTS: The study collected data on 171 trauma victims from among 1,135 eligible patients. 10 out of 171 patients (5.1%) received a final diagnosis of spinal fracture or spinal cord injury, and all of them had been assessed according to the criteria as requiring spinal immobilization. Sensitivity, specificity, positive predictive value, and negative predictive value were 100.0%, 44.7%, 10.1%, and 100.0%, respectively. On the other hand, among the 99 patients eventually judged to have required immobilization, 54 patients were not immobilized (54/99 = 54.5%) and were therefore underprotected, and among the 72 patients eventually judged to not require immobilization, 11 were over-protected (11/72 =15.3%). CONCLUSION : Clinical spine clearance criteria were useful both for judging the necessity of pre-hospital spine immobilization and for predicting spinal injuries. If these criteria can be applied to the emergency medical service system of Korea, it will contribute to the performing of appropriate spine immobilization.
Diagnosis ; Emergencies ; Emergency Medical Services ; Emergency Medical Technicians ; Extremities ; Hand ; Humans ; Immobilization* ; Korea ; Neck Pain ; Prospective Studies ; Sensitivity and Specificity ; Spinal Cord Injuries ; Spinal Fractures ; Spinal Injuries ; Spine*

An association study with Korean schizophrenic patients(N=84) and normal controls(N=87) was performed to find the relationship between catechol-o-methyltransferase(COMT) gene polymorphism and schizophrenia using polymerase chain reaction-restriction fragment length polymorphism. When we compared the allele and genotype frequencies of Bg/I COMT gene polymorphism in schizophrenics and normal controls, there was no significant difference between two groups. Our results do not support an association between the Bg/I polymorphism of COMT gene and schizophrenia.
Alleles ; Genotype ; Schizophrenia

The objective of this study is to investigate the clinical and demographic factors that influence the quality of life in patients with Parkinson's disease (PD). This is a crosssectional observational study of 47 patients in 2 hospitals with PD. All participants were asked to complete a disease-specific quality of life (QoL) questionnaire (PDQ-39). We gave a structured questionnaire interview and did a complete neurological examination on the same day. Additionally, we measured depression and dependency with the Geriatric Depression Scale-Short Form (GDS-SF) and the Korean version of the Modified Barthel Index (K-MBI).The PDQ-39 had a significant relationship with each motor part of the Unified Parkinson's Disease Rating Scale, the Korean Mini-Mental State Examination (K-MMSE), the GDS-SF, and the K-MBI (p < 0.05). The factors that independently contributed to the PDQ-39 scores were K-MMSE, GDS-SF, and K-MBI (p < 0.05). Factors having the greatest influence on the PDQ-39 were K-MBI, K-MMSE, and GDS-SF in that order. In addition, the mobility item in the K-MBI was independently a significant relating factor in the PDQ-39 (p < 0.05). These results demonstrated that dependency, especially with the mobility issue, was the greatest influence on the QoL in patients with PD.