Constructing Constraint-Based Simulation System for Creating Emergency Evacuation Plans: A Case of an Outpatient Chemotherapy Area at a Cancer Medical Center.

Making emergency evacuation plans for disaster prevention is always a high priority for hospital administrators to ensure the safety of patients and employees. This study employs the outpatient chemotherapy area of a cancer medical center as an example, and its area involves professional medical care and relatively complex human group behaviors. Hence, it is necessary to simulate evacuations in advance to formulate a special evacuation plan. To achieve this task, a constraint-based simulation system is developed with three major processes: defining spatial and activity constraints, agent-based modeling, and optimizing resource allocation. The spatial boundaries are converted from a three-dimensional model in the Building Information Modeling (BIM) to conduct a visualized simulation. Based on the spatial boundaries, the activities of the agents are set to obey the process specified by work studies. Finally, the Monte Carlo method is employed to simulate the stochastic rescue behaviors of nurses during disasters to determine the fittest resource allocation with the shortest evacuation time for different numbers of patients. The results reveal that the proposed system can output a suggested list of resource allocations and visualized results for administrators when making evacuation plans such that all the people in the area can be safely evacuated.

How Universal Are Universal Symbols? An Estimation of Cross-Cultural Adoption of Universal Healthcare Symbols.

OBJECTIVE: To evaluate the effectiveness of universal health symbol usage and to analyze the factors influencing the adoption of those symbols in Taiwan. BACKGROUND: Universal symbols are an important innovative tool for health facility wayfinding systems. Hablamos Juntos, a universal healthcare symbol system developed in the United States, is a thoughtful, well-designed, and thoroughly tested symbol system that facilitates communication across languages and cultures. METHODS: We designed a questionnaire to test how well the selected graphic symbols were understood by Taiwanese participants and determined factors related to successful symbol decoding, including participant-related factors, stimulation factors, and the interaction between stimulation and participants. Additionally, we further established a design principle for future development of localized healthcare symbols. RESULTS: (1) Eleven symbols were identified as highly comprehensible and effective symbols that can be directly adopted in Taiwanese healthcare settings. Sixteen symbols were deemed incomprehensible or confusing and thus had to be redesigned. Finally, 14 were identified as relatively incomprehensible and could thus be redesigned and then have their effectiveness evaluated again. (2) Three factors were found to influence the participants' differing levels of comprehension of the Hablamos Juntos symbols. CONCLUSIONS: In order to prevent the three aforementioned factors from causing difficulty in interpreting symbols, we suggest that the local symbol designers should (1) use more iconic images, (2) carefully evaluate the indexical and symbolic meaning of graphic symbols, and (3) collect the consensus of Taiwanese people with different educational backgrounds.

Albumin administration in patients with severe sepsis due to secondary peritonitis.

BACKGROUND: To determine whether or not intravenous administration of human albumin can reduce mortality in patients with severe sepsis due to secondary peritonitis. METHODS: Adult patients who were admitted to the surgical intensive care unit (SICU) who fulfilled the criteria of severe sepsis due to secondary peritonitis were consecutively included in this retrospective study. Patients who received and those who did not receive at least a daily minimum of 25 g intravenous human albumin for 3 days during their first 7 days of SICU admission were classified as the study group and control group, respectively. RESULTS: A total of 133 patients were included in this study. For patients with baseline serum albumin < or = 20 g/L, 28-day mortality was significantly lower in the study group. For patients with baseline serum albumin > 20 g/L, albumin administration had no significant effects on 28-day mortality. CONCLUSION: For patients with severe sepsis due to secondary peritonitis, albumin administration may reduce 28-day mortality in patients whose baseline serum albumin is < or = 20 g/L, but no such effect was found in patients whose baseline serum albumin was > 20 g/L.

Wood smoke extract promotes both apoptosis and proliferation in rat alveolar epithelial type II cells: the role of oxidative stress and heme oxygenase-1.

OBJECTIVE: Inhalation of toxic smoke causes oxidant lung injury. Alveolar epithelial type II cells are important in the re-epithelialization of alveolar walls after lung injury. We investigated the responses of alveolar epithelial type II cells to insult by wood smoke extract, and we identified the role of reactive oxygen species and heme oxygenase-1 (an oxidative stress protein) in these responses. DESIGN: A randomized, controlled study. SETTING: A research laboratory. SUBJECTS: Cultured rat L2 and primary alveolar epithelial type II cells. INTERVENTIONS AND MAIN RESULTS: Exposure of L2 alveolar epithelial type II cells to smoke extract (60 microg/mL) caused increases in reactive oxygen species, mitogen-activated protein kinases phosphorylation, heme oxygenase-1 expression, apoptosis, proliferation and cell population, all of which were largely reduced by N-acetylcysteine (an antioxidant). Additionally, the smoke extract-induced heme oxygenase-1 induction was significantly attenuated by mitogen-activated protein kinases inhibitors, by small interfering RNA targeting mitogen-activated protein kinases or by N-acetylcysteine. Furthermore, knockdown of heme oxygenase-1 by small interfering RNA prevented heme oxygenase-1 induction whereas increasing smoke extract-induced apoptosis and suppressing smoke extract-induced proliferation. Conversely, cobalt protoporphyrin IX (a heme oxygenase-1 inducer) amplified heme oxygenase-1 induction while suppressing smoke extract-induced apoptosis and augmenting smoke extract-induced proliferation. Consequently, the smoke extract-induced increase in cell population was changed into a decrease by heme oxygenase-1 small interfering RNA, but was further elevated by cobalt protoporphyrin IX. Smoke extract also caused increases in heme oxygenase-1 expression, apoptosis, proliferation and cell population in primary alveolar epithelial type II cells, and heme oxygenase-1 small interfering RNA similarly augmented smoke extract-induced apoptosis and suppressed smoke extract-induced proliferation in these primary cells. CONCLUSIONS: Smoke extract increases intracellular reactive oxygen species, which up-regulates heme oxygenase-1 via the mitogen-activated protein kinase pathways and also promotes both apoptosis and proliferation in rat alveolar epithelial type II cells. Additionally, smoke extract-induced heme oxygenase-1 induction counteracts smoke extract-induced apoptosis, but mediates smoke extract-induced proliferation, resulting in a net increase in cell population. Thus, in response to oxidant smoke insult, alveolar epithelial type II cells have evolved an adaptive mechanism involving heme oxygenase-1 that increases their cell population, presumably to help them perform their function of re-epithelialization following lung injury.

Instructor-based real-time multimedia medical simulation to update concepts of difficult airway management for experienced airway practitioners.

BACKGROUND: We integrated lecture, real-time multimedia display and medical simulation into a new renewal airway management training protocol for experienced nurse anesthetists. METHODS: Trainees of the Taiwan Association of Nurse Anesthetists from northern Taiwan and junior residents from our department were enrolled into the training program. A 4-hour renewal curriculum in the management of airway emergencies was developed, which consisted of a 2-hour general lecture (including 4 divided sections) and a 2-hour instructor-based real-time multimedia medical simulation of 4 specific techniques. After detailed explanation of each specific instrument at the beginning of each simulation, the instructors demonstrated accurate and successful management of 4 airway crises from clinical experience by using a standardized human patient simulator situated on the stage of the conference room. Meanwhile, real-time display of instructors' performance, responsive physical parameters and images from specific instruments were conducted by video camera and video processor, and projected on a 3-frame screen. Brief summary and feedback were performed after each simulation. Trainees completed a questionnaire 6 months after they participated in the training program. RESULTS: Two hundred and forty-two nurse anesthetists and 13 young residents were trained with this protocol. The questionnaire revealed that the renewal training program was useful. Participants updated their knowledge of difficult airway management, gained more confidence, improved performance, and provided effective assistance in handling airway crises. CONCLUSION: Renewing practice guidelines and teaching airway management skills, especially for difficult airway crises and protection of personnel, continues to be an important issue. Instructor-based real-time multimedia simulation is a fast, useful and systematic renewal educational method for many participants with extensive experience of airway management to update their knowledge about difficult airway management, and acquire improved decision-making and communication capabilities, skills of specific airway management.

Exacerbation of wood smoke-induced acute lung injury by mechanical ventilation using moderately high tidal volume in mice.

We investigated the effects of mechanical ventilation with a moderately high tidal volume (VT) on acute lung injury (ALI) induced by wood smoke inhalation in anesthetized mice. Animals received challenges of air, 30 breaths of smoke (30SM) or 60 breaths of smoke (60SM) and were then ventilated with a VT of 10 ml/kg (10VT) or 16 ml/kg (16VT). After 4-h mechanical ventilation, the bronchoalveolar-capillary permeability, pulmonary infiltration of inflammatory cells, total lung injury score and pulmonary expressions of interleukin-1beta and macrophage inflammatory protein-2 mRNA and proteins in the 30SM+16VT and 60SM+16VT groups were greater than those in the 30SM+10VT and 60SM+10VT groups, respectively. Additionally, the wet/dry weight ratio of lung tissues and lung epithelial cell apoptosis in the 60SM+16VT group were greater than those in the 60SM+10VT group. These differences between the 16VT and 10VT groups were not seen in animals with air challenge. Thus, mechanical ventilation with a moderately high VT in mice exacerbates ALI induced by wood smoke inhalation.

Subcutaneous emphysema associated with pneumomediastinum after general anesthesia--closed rhinolalia as an initial presentation in one of two cases.

We report two cases of subcutaneous emphysema associated with pneumomediastinum after general anesthesia. One of them was devoid of common symptoms such as chest pain and dyspnea, but significant closed rhinolalia was noted initially. Though in these two cases the chest CT scanning revealed no perivascular emphysema, we highly suspected that this phenomanum resulted from alveolar rupture with Macklin effect. Close observation was the best treatment since neither trachea injury was in evidence nor was there the occurrence of other complication. The differential diagnosis and approach to therapy are presented after review of the relevant literature.

Instability of spontaneous breathing patterns in patients with persistent vegetative state.

We investigated the breathing patterns of 27 patients in a persistent vegetative state (PVS) and 15 normal control volunteers. During the baseline period breathing air, 15 patients (the PVS-IB) exhibited irregular breathing (IB), whereas the other 12 (the PVS-OB) displayed oscillatory breathing (OB). Both groups maintained an average value for tidal volume (V(T)), total breath duration (T(TOT)), minute ventilation (V (E)), oxygen saturation (SpO2) similar to the control, but the PVS-OB displayed significantly lower end-tidal CO2 tension (P(ET)CO2) than the control. The V(T), T(TOT), V (E) and P(ET)CO2 of the PVS-OB showed cyclic changes. The coefficients of variation of V(T), T(TOT) and V (I) were: PVS-OB>PVS-IB>control. Inhalation of 100% O2 significantly reduced the respiratory variability and prevented OB of the PVS-OB. We concluded that PVS patients display respiratory instability and that brain damage, hypocapnia, and/or increased loop gain of arterial chemoreceptors may contribute to the pathogenesis of OB, whereas brain damage presumably may be the cause of IB.

Breathing pattern variability: a weaning predictor in postoperative patients recovering from systemic inflammatory response syndrome.

OBJECTIVE: To investigate whether breathing pattern variability can serve as a potential weaning predictor for postoperative patients recovering from systemic inflammatory response syndrome (SIRS). DESIGN AND SETTING: A prospective measurement of retrospectively analyzed breathing pattern variability in a surgical intensive care unit. PATIENTS: Seventy-eight mechanically ventilated SIRS patients who had undergone abdominal surgery were included when they were ready for weaning. They were divided into success (n=57) and failure (n=21) groups based upon their weaning outcome. MEASUREMENTS AND RESULTS: Before weaning, tidal volume, total breath duration, inspiratory time, expiratory time, and peak inspiratory flow were continuously monitored for 30 min, while patients received 5 cmH2O pressure support weaning trial. After the patients successfully completed the trial, they were extubated. Successful weaning was defined as patients free from the ventilator for over 48 h, whereas a weaning failure was considered as reinstitution of mechanical ventilation within 48 h of extubation. The coefficient of variation and two values of standard deviation (SD1 and SD2; indicators of the dispersion of data points in the plot) obtained from the Poincaré plot of five respiratory parameters in the failure group were significantly lower than those in the success group. The area under the receiver operating characteristic curve of these variability indices was within the range of 0.73-0.80, indicating the accuracy of prediction. CONCLUSIONS: Small breathing pattern variability is associated with a high incidence of weaning failure in postoperative patients recovering from SIRS, and this variability may potentially serve as a weaning predictor.

Linguistic analysis of the human heartbeat using frequency and rank order statistics.

Complex physiologic signals may carry unique dynamical signatures that are related to their underlying mechanisms. We present a method based on rank order statistics of symbolic sequences to investigate the profile of different types of physiologic dynamics. We apply this method to heart rate fluctuations, the output of a central physiologic control system. The method robustly discriminates patterns generated from healthy and pathologic states, as well as aging. Furthermore, we observe increased randomness in the heartbeat time series with physiologic aging and pathologic states and also uncover nonrandom patterns in the ventricular response to atrial fibrillation.