Variables influencing medical usage rates, injury patterns, and levels of care for mass gatherings

OBJECTIVES: Mass gatherings create difficult environments for which to plan emergency medical responses. The purpose of this study was to identify those variables that are associated with increased medical usage rates (MURs) and certain injury patterns that can be used to facilitate the planning process. METHODS: Patient information collected at three types of mass gatherings (professional American football and baseball games and rock concerts) over a three-year period was reviewed retrospectively. Specific variables were abstracted: (1) event type; (2) gender; (3) age; (4) weather; and (5) attendance. All 216 events (total attendance 9,708,567) studied were held in the same metropolitan region. All MURs are reported as patients per 10,000 (PPTT). RESULTS: The 5,899 patient encounters yielded a MUR of 6.1 PPTT. Patient encounters totaled 3,659 for baseball games (4.85 PPTT), 1,204 for football games (6.75 PPTT), and 1,036 for rock concerts (30 PPTT). The MUR for Location A concerts (no mosh pits) was 7.49 PPTT, whereas the MUR for the one Location B concert (with mosh pits) was 110 PPTT. The MUR for Location A concerts was higher than for baseball, but not football games (p = 0.005). Gender distribution was equal among patrons seeking medical care. The mean values for patient ages were 29 years at baseball games, 33 years at football games, and 20 years at concerts. The MUR at events held when the apparent temperature was 80 degrees F significantly lower statistically than that at events conducted at temperatures <80 degrees F were (18 degrees C) (4.90 vs. 8.10 PPTT (p = 0.005)). The occurrence of precipitation and increased attendance did not predict an increased MUR. Medical care was sought mostly for minor/basic-level care (84%) and less so for advanced-level care (16%). Medical cases occurred more often at sporting events (69%), and were more common than were cases with traumatic injuries (31%). Concerts with precipitation and rock concerts had a positive association with the incidence of trauma and the incidence of injuries; whereas age and gender were not associated with medical or traumatic diagnoses. CONCLUSIONS: Event type and apparent temperature were the variables that best predicted MUR as well as specific injury patterns and levels of care.     

Physician integration into mass gathering medical care. The United States Air Show

INTRODUCTION: Limited information exists concerning physician staffing at mass gathering events. METHODS: A retrospective review of the preparation, planning, and provision of medical care for the United States Air Show was performed. Patient encounters from the air show for the years 1981-1991 also were evaluated. RESULTS: The frequency rate of overall encounters was 8.45 patients/10,000 spectators and hospital transport rate was 0.6/10,000 spectators. The majority of complaints were related to heat or minor injuries. During this period, emergency physicians played a vital role in both medical planning and on-site staffing. Emergency medicine residents also participated. A small patient population received direct benefit from on-site physician intervention. CONCLUSION: The on-site emergency physician is of benefit in event preplanning and reducing the burden on the EMS system during mass gathering events.     

Mass gathering medicine: The Melbourne 2006 Commonwealth Games experience

Objective: To investigate the nature and acuity of medical presentations of patrons and staff attending the Melbourne 2006 Commonwealth Games (M2006) venues and festival live sites. Design and setting: Retrospective case series chart audit of patients who were managed by St John Ambulance during the M2006. Participants: Patients who presented requiring first‐aid review or treatment at any of the 21 designated event venues or 16 live sites during their prescribed operating hours between 15 March 2006 and 26 March 2006. Main outcome measures: Provisional diagnosis and ambulance transport to hospital. Results: A total of 3514 presentations occurred during the study period, of which 2279 (64.9%, 95% CI, 63.3%–66.4%) occurred at event venues. Headaches, soft tissue injuries, blisters and other wounds accounted for 64.1% (95% CI, 62.5%–65.73%) of presentations. A total of 303 patients were referred for further medical care, including 69 patients (1.96%, 95% CI, 1.54%–2.49%) who required transport to hospital via ambulance. Traumatic injuries accounted for 42.0% (95% CI, 30.5%–54.5%) of patients transported by ambulance to hospital. The patient presentation rate across all venues was 0.857 per 1000 patrons. The transport to hospital rate was 0.0186 per 1000 patrons. Conclusions: The majority of first‐aid presentations during the M2006 were of low acuity and treatment resulted in return of patrons to the event, with only a small number requiring ambulance transport to hospital.     

Analysis of a medical tent at the Toronto Caribana Parade

Objectives. To review the experience with an on-site medical tent for a mass gathering and to analyze patient records in a manner to more appropriately allocate resources and identify possible delays in definitive care. Methods. The logistics of providing an on-site medical tent is reviewed, followed by a retrospective chart review of 126 patients over a two-year period. Prior to the chart review, an injury classification was developed that categorized patients based on the necessity of transport to hospital. Data were also analyzed for times of peak patient flow, types of injuries, and needless delays in definitive care. Results. An average of 63 patients (95% CI 44-77) were seen in the tent and 1.3 patients sought care per 10,000 spectators. Peak times were between 1600 and 2000 hours. The average number of patients each hour was 6.5 (95% CI 0-13). Severe, intermediate, and minor injuries accounted for 16%, 38%, and 46% of total injuries, respectively. Nine cases were found where the patients arrived and left the medical tent by ambulance. Four of these instances may have represented a needless delay in definitive care. The details of each of these cases are reviewed. Conclusions. The results indicate that on-site medical coverage, with appropriate supports, is indeed safe. The framework provided with regard to setup and analysis of workload will help others in the planning of medical care for similar mass gatherings. PREHOSPITAL EMERGENCY CARE 2002;6:199-203     

Effect of crowd size on patient volume at a large, multipurpose, indoor stadium

A prediction of patient volume expected at "mass gatherings" is desirable in order to provide optimal on-site emergency medical care. While several methods of predicting patient loads have been suggested, a reliable technique has not been established. This study examines the frequency of medical emergencies at the Syracuse University Carrier Dome, a 50,500-seat indoor stadium. Patient volume and level of care at collegiate basketball and football games as well as rock concerts, over a 7-year period were examined and tabulated. This information was analyzed using simple regression and nonparametric statistical methods to determine level of correlation between crowd size and patient volume. These analyses demonstrated no statistically significant increase in patient volume for increasing crowd size for basketball and football events. There was a small but statistically significant increase in patient volume for increasing crowd size for concerts. A comparison of similar crowd size for each of the three events showed that patient frequency is greatest for concerts and smallest for basketball. The study suggests that crowd size alone has only a minor influence on patient volume at any given event. Structuring medical services based solely on expected crowd size and not considering other influences such as event type and duration may give poor results.     

Prehospital severity scoring at major rock concert events

INTRODUCTION: Rock and contemporary music concerts are popular, recurrent events requiring on-site medical staffing. STUDY OBJECTIVE: To describe a novel severity score used to stratify the level of acuity of patients presenting to first-aid stations at these events. METHODS: Retrospective review of charts generated at the first-aid stations of five major rock concerts within a 60,000 spectator capacity, outdoor, professional sports stadium. Participants included all concert patrons presenting to the stadium's first-aid stations as patients. Data were collected on patient demographics, history of drug or ethanol usage while at the concert event, first-aid station time, treatment rendered, diagnosis, and disposition. All patients evaluated were retrospectively assigned a "DRUG-ROCK" Injury Severity Score (DRISS) to stratify their level of acuity. Individual concert events and patient dispositions were compared statistically using chi-square, Fisher's exact, and the ANOVA Mean tests. RESULTS: Approximately 250,000 spectators attended the five concert events. First-aid stations evaluated 308 patients (utilization rate of 1.2 per 1,000 patrons). The most common diagnosis was minor trauma (130; 42%), followed in frequency by ethanol/illicit drug intoxication (98; 32%). The average time in the first-aid station was 23.5 +/- 22.5 minutes (+/- standard deviation; range: 5-150 minutes). Disposition of patients included 100 (32.5%) who were treated and released; 98 (32%) were transported by paramedics to emergency departments (EDs); and 110 (35.5%) signed-out against medical advise (AMA), refusing transport. The mean DRISS was 4.1 (+/- 2.65). Two-thirds (67%) of the study population were ranked as mild by DRISS criteria (score = 1-4), with 27% rated as moderate (score = 5-9), and 6% severe (score > 10). The average of severity scores was highest (6.5) for patients transported to hospitals, and statistically different from the scores of the average of the treated and released and AMA groups (p < 0.005). CONCLUSION: The DRISS was useful in stratifying the acuity level of this patient population. This severity score may serve as a potential triage mechanism for future mass gatherings such as rock concerts.     

A case series analysis of mass casualty incidents

Introduction. Mass casualty incidents (MCIs) are infrequent but potentially overwhelming events that can stress the capabilities of even the most organized emergency medical services (EMS) system. The Maryland EMS system has been identified as a pioneer and leader in the field of prehospital emergency care and, as with many states, Maryland's regional preparation for MCIs has been integrated into its overall EMS systems planning. Objective. To determine how successful this integration has been by examining a three-year history of response to MCIs in Maryland. Methods. A three-year case series of MCIs in Maryland was obtained from a Nexis national news publications search. These MCIs were cross-referenced with U.S. postal ZIP codes and the U.S. Census Bureau's ZIP code files. They were then mapped and summary statistics were prepared for analysis. Data obtained through the Maryland Health Services Cost Review Commission for all severely injured patients discharged from Maryland hospitals were obtained over the same three-year period for comparison. Results. Eight MCIs occurred over a three-year period, resulting in a total of 203 injuries. An average of 25.4 ± 10.7 injuries occurred per MCI. A total of 158 (77.8%) of injuries necessitated ambulance transportation. An average of 3.1 ± 1.1 hospitals were involved per MCI. Conclusions. The Maryland EMS system was effective in responding to MCIs ranging in size from 10 to nearly 40 injuries. Analyzing MCIs that reoccur on a year-to-year basis should figure into the planning process for EMS systems. PREHOSPITAL EMERGENCY CARE 2000;4:299-304     

Review of accidents/injuries among emergency medical services workers in Baltimore, Maryland

OBJECTIVES: To characterize the types of occupational exposures and injuries reported by emergency medical service (EMS) workers. METHODS: A blinded review of accidents/exposures among EMS workers employed by a Baltimore County fire department was conducted. Medical records for 1992 were reviewed. RESULTS: Two hundred and twenty-six reports were filed by EMS workers (n = 197) employed by a large, urban fire department in 1992. The most commonly reported injuries were sprains (23%), strains (20%), and exposure to blood and body fluids (15%). The body site most commonly injured was the back (20%) followed by the respiratory system (10%). Most incidents were treated at the employee health clinic, and 13% of the incidents resulted in a hospital visit. Fifteen percent of the injuries resulted in more than seven lost work days. Most incidents were caused by stretcher mishaps, especially during transport of heavy patients. Walkway impediments (e.g., icy steps, wet leaves, broken and uneven pathways) also played an important role in creating slipping and tripping hazards. CONCLUSION: These results suggest a variety of prevention strategies aimed at reducing accidents and exposures among EMS workers.     

A C ASE S ERIES A NALYSIS OF M ASS C ASUALTY I NCIDENTS

Introduction. Mass casualty incidents (MCIs) are infrequent but potentially overwhelming events that can stress the capabilities of even the most organized emergency medical services (EMS) system. The Maryland EMS system has been identified as a pioneer and leader in the field of prehospital emergency care and, as with many states, Maryland's regional preparation for MCIs has been integrated into its overall EMS systems planning. Objective. To determine how successful this integration has been by examining a three-year history of response to MCIs in Maryland. Methods. A three-year case series of MCIs in Maryland was obtained from a Nexis national news publications search. These MCIs were cross-referenced with U.S. postal ZIP codes and the U.S. Census Bureau's ZIP code files. They were then mapped and summary statistics were prepared for analysis. Data obtained through the Maryland Health Services Cost Review Commission for all severely injured patients discharged from Maryland hospitals were obtained over the same three-year period for comparison. Results. Eight MCIs occurred over a three-year period, resulting in a total of 203 injuries. An average of 25.4 ± 10.7 injuries occurred per MCI. A total of 158 (77.8%) of injuries necessitated ambulance transportation. An average of 3.1 ± 1.1 hospitals were involved per MCI. Conclusions. The Maryland EMS system was effective in responding to MCIs ranging in size from 10 to nearly 40 injuries. Analyzing MCIs that reoccur on a year-to-year basis should figure into the planning process for EMS systems.     

Hospital-based healthcare provider (nurse and physician) integration into an emergency medical services-managed mass-gathering event

INTRODUCTION: This report describes not only the implementation of a coordinated emergency medical services-hospital-based healthcare team but also investigates the integration of nurse-physician teams at a mass gathering medical care event. METHODS: A review of resource utilization, patient encounters, and local ED census was performed during this period at a college football stadium. RESULTS: During this 4-year period, 1681 patients presented for medical care during 26 events with a total attendance of 1,544,244 (1.09 patients per thousand attendees [PT]). The majority of patient contacts were for minor complaints (1451, 87.6%), whereas 205 (12.4%) received full evaluations (focused history and physical examination most often with pulse oximetric and electrocardiographic monitoring). A total of 109 patients were transported (4.19 PT), representing 6.48% of all patients. Patient census for the event medical deployment increased from 0.44 PT in 2001 to 1.75 PT in 2004. The number and percent of patients transported also increased between 2001 (0.02 PT, 4.48%) and 2004 (0.12 PT, 6.67%). However, 118 (57.6%) patients who received full evaluations were able to be discharged by a physician, avoiding transport. Chief complaints and management of patients receiving full evaluations were consistent across this period, with altered mental status (52.7%) and chest pain (12.7%) as the most common complaints. Average ED census during this period was found to be significantly higher on event days (176.2) than nonevent days (161.2) (t = 8.04, P < .001), although this produced only a minor impact on the emergent care system. CONCLUSION: This study describes one potential deployment plan for a mass gathering medical event and suggests that the incorporation of physicians into a mass gathering setting may be associated with an absolute increase in patient census and transports, while decreasing the percent of patients transported. The impact on local emergency medical services and ED resources, although not specifically investigated in this study, was likely minimal.     

Burning man 2011: mass gathering medical care in an austere environment

Abstract Introduction. Burning Man is a large weeklong outdoor arts festival held annually in the rugged and austere Black Rock Desert in northern Nevada. The 2011 event presented several unusual challenges in terms of emergency medical services (EMS) and medical care provision. Objective. This paper details the planning and subsequent emergency medical care for Burning Man 2011. Methods. This was a retrospective, observational review of the preparation, management, and medical care at Burning Man 2011. Results. Attendance at Burning Man 2011 was 53,735. Of these attendees, 2,307 were treated in the field hospital. While most patients had minor injuries, 33 were subsequently transported to a hospital (28 by ambulance and five by helicopter). The most common conditions treated were soft-tissue injuries, dehydration, eye problems, and urinary tract infections. There was one death (subarachnoid hemorrhage) and one patient in cardiac arrest (thoracic aortic dissection) who was successfully resuscitated and transferred. Burning Man 2011 presented numerous challenges in provision of EMS and medical care because of attendance size, the austere environment, and significant distance (150 miles) to definitive medical care. EMS operations included six dedicated ambulances, three quick-response vehicles, two first-aid stations, and a physician-staffed field hospital. The hospital had limited diagnostic capabilities (e.g., x-ray, ultrasound, basic laboratory analysis) and a limited formulary. We found that the use of physicians was necessary because much of the care provided was beyond the scope of paramedics. Conclusions. We describe the preparation and medical care for a large outdoor mass-gathering event held in a remote and austere environment. We met the stated goals of providing needed medical care while minimizing the need to transport attendees offsite for additional care. Our experience with Burning Man 2011 may aid planners with similar events.     

Medical care for a mass gathering: the Suwa Onbashira Festival

INTRODUCTION: The Suwa Onbashira Festival is held every six years and draws approximately one million spectators from across Japan. Men ride the Onbashira pillars (logs) down steep slopes. At each festival, several people are crushed under the heavy log. During the 2004 festival, for the first time, a medical care system that coordinated a medical team, an emergency medical service, related agencies, and local hospitals was constructed. OBJECTIVE: The aims of this study were to characterize the spectrum of injuries and illness and to evaluate the medical care system of this festival. METHODS: The festival was held 02 April-10 May 2004. The medical records of all of the patients who presented to an on-site medical tent or who were treated at the scene and transported to hospitals over a 12-day period were reviewed. The following items were evaluated: (1) the emergency medical system at the festival; (2) the environmental circumstances; and (3) patient data. RESULTS: All medical usage rates are reported as patients per 10,000 attendees (PPTT). A total 1.8 million spectators attended the festival during the 12-day study period; a total of 237 patients presented to the medical tent (1.32 PPTT), and 63 (27%) were transferred to hospitals (0.35 PPTT). Of the total, 135 (57%) suffered from trauma--two were severely injured with pelvic and cervical spine fractures; and 102 (43%) had medical problems including heat-related illness. CONCLUSIONS: Comprehensive medical care is essential for similar mass gatherings. The appropriate triage of patients can lead to efficient medical coverage.     

Out-of-hospital and Emergency Department Management of Epidemic Scombroid Poisoning

OBJECTIVE: To report two epidemic outbreaks of scombroid food poisoning and their emergency medical services (EMS) response and emergency department (ED) treatment, analyzing the impact of early physician involvement and on-line medical control. METHODS: Retrospective case series of two multiple-casualty incidents (MCIs) involving scombroid food poisoning. RESULTS: A total 57 patients were treated from two separate incidents, with 30 patients transported to area hospitals. One patient required treatment with a cardiac medication in the field and another patient eventually required hospital admission. On-scene medical control (incident 1) and early identification of the index case (incident 2) were instrumental to out-of-hospital care interventions and conservation of resources. Patient triage, field treatment, and hospital transport were expedited, with some patients treated and released from the scene. CONCLUSIONS: Immediate diagnosis of a food-borne illness in the out-of-hospital setting allows rapid treatment at the scene and allows for the efficient transport of multiple patients to a single receiving facility. EMS medical directors should be able to immediately respond to such incidents to make presumptive diagnoses and accurately direct patient care. When this is not possible, early identification of the index case facilitates early diagnosis and treatment.     

A GITATED D ELIRIUM AND S UDDEN D EATH : T WO C ASE R EPORTS

Objective. To determine the chemicals involved in fire department hazardous materials (hazmat) responses and analyze the concomitant emergency medical services' patient care needs. Methods. The setting was a mid-sized metropolitan area in the southwestern United States with a population base of 400,000 and an incorporated area of 165 square miles. The authors conducted a retrospective evaluation of all fire department hazmat reports, with associated emergency medical services patient encounter forms, and in-patient hospital records from January 1, 1992, through December 31, 1994. Results. The fire department hazardous materials control team responded to 468 hazmat incidents, involving 62 chemicals. The majority of incidents occurred on city streets, with a mean incident duration of 46 minutes. More than 70% of the responses involved flammable gases or liquids. A total of 32 incidents generated 85 patients, 53% of whom required transport for further evaluation and care. Most patients were exposed to airborne toxicants. Only two patients required hospital admission for carbon monoxide poisoning. Conclusion. Most hazmat incidents result in few exposed patients who require emergency medical services care. Most patients were exposed to airborne toxicants and very few required hospitalization. Routine data analysis such as this provides emergency response personnel with the opportunity to evaluate current emergency plans and identify areas where additional training may be necessary.     

Pediatric emergency care in a metropolitan area

Regional emergency medical services (EMS) system planning requires a data base describing the population to be served. No such regional data base exists for childhood emergencies. This study was undertaken for two reasons: (1) to establish, in a metropolitan region, the demographics of the population and the type of clinical problems for which pediatric emergency care is sought, and (2) to determine if the critical care categories used for EMS planning accurately reflect the emergency care needs of pediatric patients in the region.

All pediatric visits (6,190) to 13 area hospitals during 1 month were reviewed. The most common diagnostic categories seen were trauma (48%) and infectious illness (29%).

Six hundred and six visits satisfied criteria for inclusion in one of the following critical care categories: trauma, poisonings, burns, spinal cord injuries, behavioral disorders, cardiovascular illness, and a general category designated “medical.” The last group was the largest of the categories (185 visits) and contained the greatest number of seriously or critically ill children.

Of the total visits, 9.5% were by children 1 year or under, and 19.1% were by children 13 to 16 years old. For visits of a serious or critical nature, these age groups comprised 16% and 29%, respectively, of the total for such visits.

This study documents that the emergency care needs of children differ from those of adults and deserve special attention in the planning of emergency care systems.     

Concert Medicine: Spectrum of Medical Problems Encountered at 405 Major Concerts

OBJECTIVES: To identify factors predictive of patient load at major commercial concert first-aid stations, and to characterize the spectrum of presenting injuries and illnesses at such events. METHODS: This study was a retrospective case series of patients presenting to on-site first-aid stations at five major concert venues in southern California over a five-year period. The authors compared the number of patients per ten thousand attendees (PPTT) with four potential predictors (music type, overall attendance, temperature, and indoor vs outdoor location) using univariate techniques and negative binomial regression. The spectrum of chief complaints observed is described. RESULTS: There were 1,492 total patients out of 4,638,099 total attendees at 405 separate concerts. The median patient load per concert was 2.1 PPTT, ranging from 0 PPTT at 53 concerts to 71 PPTT at a punk rock festival that turned into a riot. Patient load varied significantly by music category (p = 0.0001) but not with overall attendance, temperature, or indoor vs outdoor location. Median PPTT by music category ranged from 1.3 PPTT for rhythm and blues to 12.6 PPTT for gospel/Christian, with negative binomial regression indicating that rock concerts had 2.5 times (95% CI = 2.0 to 3.0) the overall patient load of non-rock concerts. Music type, however, was able to account for only 4% of the variability observed in the regression model. Trauma-related complaints predominated overall, with similar rates at rock and non-rock concerts. Four cardiac arrests occurred at classical concerts. CONCLUSION: Rock concert first-aid stations evaluated 2.5 times the patient load of non-rock concerts overall, although there was substantial concert-to-concert variability. Trauma-related complaints predominate at both rock and non-rock events. These data may assist individuals and organizations planning support for such events.