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Surge Capacity Planning: A New Paradigm
Research Forum Abstracts Methods: First, the expression of irp94 mRNA was tested after the reperfusion of the transient forebrain ischemia induction at the central nervous system in three Mongolian gerbils. Second, irp94 expression in PC12 cells, which are derived from transplantable rat pheochromocytoma cultured in the DMEM media, was tested at transcriptional and translational levels. The half life of irp94 mRNA was also determined in PC12 cells. Last, the changes of irp94 mRNA expression were investigated by the addition of various ER stress inducible chemicals (A23187, BFA, tunicamycin, DTT and H2O2) and proteasome inhibitors, and heat shock. Results: High level expression of irp94 mRNA was detected after 3 hours reperfusion in the both sites of the cerebral cortex and hippocampus of the gerbil brain. The main regulation of irp94 mRNA expression in PC12 cells was determined at the transcriptional level. The half life of irp94 mRNA in PC12 cells was approximately 5 hours after the initial translation. The remarkable expression of irp94 mRNA was detected by the treatment of tunicamycin, which blocks glycosylation of newly synthesized polypeptides, and H2O2, which induces apoptosis. When PC12 cells were treated with the cytosol proteasome inhibitors such as ALLN (N-acetyl-leucyl-norleucinal) and MG 132 (methylguanidine), irp94 mRNA expression was increased. Conclusions: These results indicate that expression of irp94 was induced by ER stress including oxidation condition and glycosylation blocking in proteins. Expression of irp94 was increased when the cells were chased after heat shock, suggesting that irp94 may be involved in recovery rather than protection against ER stresses. In addition, irp94 expression was remarkably increased when cytosol proteasomes were inhibited by ALLN and MG 132, suggesting that irp94 plays an important role for maintaining the ERAD (endoplasmic reticulum associated degradation) function.
245
Potential Under-Triage of Acute Non-Traumatic Conditions Using the Simple Triage and Rapid Treatment System
Madsen BE, Sztajnkrycer MD, Baez AA, Mayo Clinic, Rochester, MN
Study Objectives: While the majority of immediate disaster victims sustain acute traumatic injuries, the potential exists for concomitant medical emergencies. The most common disaster triage tool, Simple Triage and Rapid Treatment (START), utilizes ambulatory capacity, pulse, mentation, and respiration as surrogate markers of severity. The purpose of this study was to determine whether START adequately triages patients suffering from an acute non-traumatic condition. Methods: Retrospective IRB-approved study utilizing two national ICD-9-based disease outcomes databases. Mortality outcome data was obtained the 1998 CDC WONDER Compressed Mortality Data Request and the National Center for Health Statistics National Hospital Discharge Summary (NHDS). Crude Mortality Rate (CMR) was determined from the total deaths divided by the total US population, normalized per 100,000 population. Adjusted Mortality Rate (AMR) corrected the total population based upon disease incidence. NHDS mortality data (NMD) was determined from the 2003 NHDS, and referred to percent individuals with discharge code of "deceased" for the ICD-9 code of interest. Results: CMR, AMR, and NMD were calculated for 45 traumatic and 22 nontraumatic conditions. Despite a high likelihood of being triaged as ambulatory, AMR for four sentinel medical conditions (acute myocardial infarction, unstable angina, pulmonary embolism, and acute asthma exacerbation) were 3579.8, 41.2, 1143.8, and 46.2 per 100,000 population respectively. In contrast, individuals with selected lower extremity orthopedic injuries (tibia fractures and femur fractures), who would likely be triaged as non-ambulatory and therefore prioritized for treatment and transportation, had AMRs of 20.4 and 54.9 per 100,000 population. Similar findings were noted for both CMR and NMD. Conclusion: As ambulatory patients bypass START physiological discriminators, individuals with potentially life-threatening medical conditions may be under-triaged using the START system, thereby delaying treatment and transport to definitive care. Based upon these findings, use of START in triaging disaster victims presenting with isolated medical complaints may not be appropriate.
246
Surge Capacity Planning: A New Paradigm
Williams JM, Mueller MJ, Martin W, University of Rochester Medical Center, Rochester, NY; Consultant, Pittsford, NY; Air Worldwide, Corp, Boston, MA
Study Objectives: Apply risk modeling technology to estimate probability of terrorism, likely terror weapons and associated health outcomes in a medium-sized
Volume 46, no. 3 : September 2005
metropolitan region to identify the nature and magnitude of the more likely terrorism related mass casualty scenarios as a tool for emergency preparedness and hospital surge planning purposes. Methods: A probabilistic terrorism model based on input from a panel of counter-terrorism experts was used to simulate terrorism events over 500 thousand iterated years for a 9 county area with a population of 1.2 million. This analysis determined the likelihood of a terrorist event using various types of weapons (Chemical, Biological, Radiological, Nuclear and Explosive). Its output was a probability distribution of victims by number and injury classification (minor, moderate, life-threatening and fatal). Results: The model identified 1,902 terrorist events. The likelihood of a terrorist attack in the region that would result in injury was estimated to be 3.7% over a 10 year period. More than 61% of the simulated attacks on the study area involved radiological, 22% chemical, 7% nuclear and 6% biological weapons. There was just a 3% probability that conventional explosives would be used. The most likely ordnance was Cesium. Attacks employing this agent could cause up to 14k moderate and 11k minor injuries. Of all modeled events, a large nuclear attack could cause the greatest number of deaths (128k) and injuries (68k life-threatening, 145k moderate, and 507k minor). The most frequent chemical event employed VX (1k fatalities, 1k lifethreatening, 29k moderate, 142k minor). The most common biological event involved smallpox (30k fatalities, 9k life-threatening, 16k moderate and 6k minor). The most likely conventional weapon was a portable bomb (3 fatalities, 3 lifethreatening, 41 moderate and 339 minor injuries). There was a 1 in 640 chance in any given year that the number of victims of an attack with life-threatening and moderate injuries would exceed the current surge planning factor of 500 beds per million population. Conclusion: Although the overall risk of terrorism in the area studied is low, attacks with varying likelihoods could result in a demand for emergency medical services that would exceed the current health system’s capacity to respond. Modeling provides a tool to determine where to invest limited resources in planning and preparing for terrorist related mass casualty incidents. It use enables planners to address any associated resource, policy, financial and ethical issues before disaster strikes.
247
Potential Use of a Single Ventilator for Multiple Victim Ventilation
Irvin CB, Neyman G, St John Hospital and Medical Center, Detroit, MI
After the events of September 11, 2001, there has been a focus on anticipating the need for medical care for large numbers of potential victims. While government resources would eventually be available, there may be a time when hospitals may need to provide respiratory support for more patients than available ventilators (large botulism outbreak, for example). While manual ventilation (bagging) is possible, it is also possible that the additional personnel requirements would not be available. Objective: To determine if a ventilator available in our emergency department could quickly be modified to provide ventilation for 4 adults simultaneously. Methods: Using lung simulators, readily available plastic tubing, and one of our ventilators (840 Series Microprocessor Ventilator, Puritan-Bennett Corp), human lung simulators were added in series until the ventilator was ventilating he equivalent of 4 adults. Data collected included peak pressure, peep, Total Tidal Volume, Total Minute ventilation, respiratory rate, and I: E ratios. A visual inspection also occurred to document any obvious asymmetry in the delivery of gas to the lung simulators. The ventilator was run for 12 consecutive hours (6 hours of pressure control and 6 hours of volume control). Results: Using readily available plastic tubing, set up to minimize dead space volume, the 4 lung simulators were easily ventilated for 12 hours using one ventilator. In pressure control (set at 25mmHg), the mean tidal volume was 1910 (approximately 477 cc/lung simulator), with an average minute ventilation of 30.6 L/ min or (7.65 l/min/simulated lung). In volume control (set at 2 liters), the mean peak pressure was 27.5, and the minute ventilation was 32.5 L/min total (8.13 L/min/lung simulator). Conclusion: In cases of dire emergency, a single ventilator may be quickly modified to ventilate 4 potential adults for a limited time. The volumes delivered in this simulation should be able to sustain four 70 kg individuals. While issues such as potential infectious complications and the need to further study this on living animals remain, this pilot study suggests significant potential for expansion in the use of a single ventilator during dire emergencies.
Annals of Emergency Medicine S69
245
Potential Under-Triage of Acute Non-Traumatic Conditions Using the Simple Triage and Rapid Treatment System
Madsen BE, Sztajnkrycer MD, Baez AA, Mayo Clinic, Rochester, MN
Study Objectives: While the majority of immediate disaster victims sustain acute traumatic injuries, the potential exists for concomitant medical emergencies. The most common disaster triage tool, Simple Triage and Rapid Treatment (START), utilizes ambulatory capacity, pulse, mentation, and respiration as surrogate markers of severity. The purpose of this study was to determine whether START adequately triages patients suffering from an acute non-traumatic condition. Methods: Retrospective IRB-approved study utilizing two national ICD-9-based disease outcomes databases. Mortality outcome data was obtained the 1998 CDC WONDER Compressed Mortality Data Request and the National Center for Health Statistics National Hospital Discharge Summary (NHDS). Crude Mortality Rate (CMR) was determined from the total deaths divided by the total US population, normalized per 100,000 population. Adjusted Mortality Rate (AMR) corrected the total population based upon disease incidence. NHDS mortality data (NMD) was determined from the 2003 NHDS, and referred to percent individuals with discharge code of "deceased" for the ICD-9 code of interest. Results: CMR, AMR, and NMD were calculated for 45 traumatic and 22 nontraumatic conditions. Despite a high likelihood of being triaged as ambulatory, AMR for four sentinel medical conditions (acute myocardial infarction, unstable angina, pulmonary embolism, and acute asthma exacerbation) were 3579.8, 41.2, 1143.8, and 46.2 per 100,000 population respectively. In contrast, individuals with selected lower extremity orthopedic injuries (tibia fractures and femur fractures), who would likely be triaged as non-ambulatory and therefore prioritized for treatment and transportation, had AMRs of 20.4 and 54.9 per 100,000 population. Similar findings were noted for both CMR and NMD. Conclusion: As ambulatory patients bypass START physiological discriminators, individuals with potentially life-threatening medical conditions may be under-triaged using the START system, thereby delaying treatment and transport to definitive care. Based upon these findings, use of START in triaging disaster victims presenting with isolated medical complaints may not be appropriate.
246
Surge Capacity Planning: A New Paradigm
Williams JM, Mueller MJ, Martin W, University of Rochester Medical Center, Rochester, NY; Consultant, Pittsford, NY; Air Worldwide, Corp, Boston, MA
Study Objectives: Apply risk modeling technology to estimate probability of terrorism, likely terror weapons and associated health outcomes in a medium-sized
Volume 46, no. 3 : September 2005
metropolitan region to identify the nature and magnitude of the more likely terrorism related mass casualty scenarios as a tool for emergency preparedness and hospital surge planning purposes. Methods: A probabilistic terrorism model based on input from a panel of counter-terrorism experts was used to simulate terrorism events over 500 thousand iterated years for a 9 county area with a population of 1.2 million. This analysis determined the likelihood of a terrorist event using various types of weapons (Chemical, Biological, Radiological, Nuclear and Explosive). Its output was a probability distribution of victims by number and injury classification (minor, moderate, life-threatening and fatal). Results: The model identified 1,902 terrorist events. The likelihood of a terrorist attack in the region that would result in injury was estimated to be 3.7% over a 10 year period. More than 61% of the simulated attacks on the study area involved radiological, 22% chemical, 7% nuclear and 6% biological weapons. There was just a 3% probability that conventional explosives would be used. The most likely ordnance was Cesium. Attacks employing this agent could cause up to 14k moderate and 11k minor injuries. Of all modeled events, a large nuclear attack could cause the greatest number of deaths (128k) and injuries (68k life-threatening, 145k moderate, and 507k minor). The most frequent chemical event employed VX (1k fatalities, 1k lifethreatening, 29k moderate, 142k minor). The most common biological event involved smallpox (30k fatalities, 9k life-threatening, 16k moderate and 6k minor). The most likely conventional weapon was a portable bomb (3 fatalities, 3 lifethreatening, 41 moderate and 339 minor injuries). There was a 1 in 640 chance in any given year that the number of victims of an attack with life-threatening and moderate injuries would exceed the current surge planning factor of 500 beds per million population. Conclusion: Although the overall risk of terrorism in the area studied is low, attacks with varying likelihoods could result in a demand for emergency medical services that would exceed the current health system’s capacity to respond. Modeling provides a tool to determine where to invest limited resources in planning and preparing for terrorist related mass casualty incidents. It use enables planners to address any associated resource, policy, financial and ethical issues before disaster strikes.
247
Potential Use of a Single Ventilator for Multiple Victim Ventilation
Irvin CB, Neyman G, St John Hospital and Medical Center, Detroit, MI
After the events of September 11, 2001, there has been a focus on anticipating the need for medical care for large numbers of potential victims. While government resources would eventually be available, there may be a time when hospitals may need to provide respiratory support for more patients than available ventilators (large botulism outbreak, for example). While manual ventilation (bagging) is possible, it is also possible that the additional personnel requirements would not be available. Objective: To determine if a ventilator available in our emergency department could quickly be modified to provide ventilation for 4 adults simultaneously. Methods: Using lung simulators, readily available plastic tubing, and one of our ventilators (840 Series Microprocessor Ventilator, Puritan-Bennett Corp), human lung simulators were added in series until the ventilator was ventilating he equivalent of 4 adults. Data collected included peak pressure, peep, Total Tidal Volume, Total Minute ventilation, respiratory rate, and I: E ratios. A visual inspection also occurred to document any obvious asymmetry in the delivery of gas to the lung simulators. The ventilator was run for 12 consecutive hours (6 hours of pressure control and 6 hours of volume control). Results: Using readily available plastic tubing, set up to minimize dead space volume, the 4 lung simulators were easily ventilated for 12 hours using one ventilator. In pressure control (set at 25mmHg), the mean tidal volume was 1910 (approximately 477 cc/lung simulator), with an average minute ventilation of 30.6 L/ min or (7.65 l/min/simulated lung). In volume control (set at 2 liters), the mean peak pressure was 27.5, and the minute ventilation was 32.5 L/min total (8.13 L/min/lung simulator). Conclusion: In cases of dire emergency, a single ventilator may be quickly modified to ventilate 4 potential adults for a limited time. The volumes delivered in this simulation should be able to sustain four 70 kg individuals. While issues such as potential infectious complications and the need to further study this on living animals remain, this pilot study suggests significant potential for expansion in the use of a single ventilator during dire emergencies.
Annals of Emergency Medicine S69