Physicians face off with triple digit weather incidents, stampede in prehospital event.
Famous artists. A hundred-degree weather. False reports of gunfire. And a stampede leading to an Mass Casualty Incident (MCI) declaration by local fire and EMS. All in all, it made for an eventful music festival.
Like any MCI event, there were several learning opportunities involving both direct patient care and operational considerations that became apparent while overseeing the medical care at the event as prehospital physicians.
Heat Illness
Exertional heat illness encompasses clinical presentations that are incredibly varied and can be difficult to diagnose. Mild symptoms include muscle cramps, headache, weakness, and heat related syncope. More severe forms of illness include “heat injury,” which is defined as end organ damage due to hyperthermia (but lacking changes in mental status). The most severe form is heat stroke, which is end organ damage coupled by encephalopathy and altered mental status.
Generally, peripheral temperatures do not reflect the true potential for heat illness; thus, it is imperative to get a core rectal temperature on every altered patient. In heat stroke, cardiac output decreases as a result of end-organ damage thereby causing peripheral vascular vasoconstriction and lower peripheral temperatures rendering axillary and peripheral skin temperatures inaccurate and unreliable.
One young male was carried into the medical clinic by friends for syncope which sounded benign enough. EKG revealed no arrhythmogenic causes of syncope. However, even when recumbent and after multiple liters of intravenous fluids, the patient had recurrent syncope and was slightly altered per his family.
Although the core temperature was not significantly elevated, he was transported to the ED for further evaluation, of which an atypical presentation of heat stroke was high on the differential. He was one out of hundreds of patients who suffered some degree of heat illness that day.
Persistent Tachycardia
Among a deluge of patients with mild heat illness or syncope, it is important to stay vigilant and not chalk up every presentation to these two processes. We had the case of a 44-year-old male with no PMH who presented for lightheadedness. Vitals were all normal except for a HR of 144. Again, despite fluids, the patient’s HR remained at 144 during his entire course, although he did feel better. It was very tempting to discharge this well appearing patient as we were being inundated with patients and he simply wanted to go home.
After rechecking the HR a third time, the rate had still not changed and we decided to obtain an EKG, which revealed that the patient was in Atrial Flutter. He could not tell us exactly when his symptoms started. Given he had no evidence of VS instability, we decided to rate control him with Diltiazem.
There are actually a few studies detailing prehospital use of Diltiazem. Some providers are hesitant to approve this medication in the prehospital setting because of possible hypotension.
However, in one retrospective review where 278 patients received prehospital Diltiazem, only two patients experienced an episode of hypotension. The average dose given was 16.7 mg and 73% of patients had a HR drop of >20%. Our patient safely received diltiazem (0.25mg/kg) and his HR lowered to 110. The patient then had follow-up arranged to determine the need for possible cardioversion and anticoagulation.
Defining and Managing an MCI (or two)
A MCI is defined as an incident where the number of patients overwhelms local resources. Mass gathering events have an enormous potential to place a severe strain on the local health care system, possibly even delaying local residents from obtaining the healthcare to which they are entitled. To prevent this, event organizers must prepare for communicable disease outbreaks, injuries to participants, adequate crowd control, and proper on-site medical care. At this festival, we were faced with two of these events. The first was a gradual mass casualty from heat due to a lack of shade, lack of cooling stations, and early show times which coincided with the hottest parts of the day. The festival’s show times were 11am-11pm; other festivals in that locale started much later in the day through the early morning and in New York City, you cannot get a music festival permitted before 1pm in order to avoid the peak heat index of the day.
At one point during the heat catastrophe, there were many more pending calls requesting EMS response than available EMS units. With a declaration as a MCI by local Fire & EMS, outside prehospital resources from the city entered the venue to respond and transport more patients to the medical clinic on-site. With the full resources of the city available, city buses were brought in to act as cooling stations to offer a respite to a significant proportion of attendees with heat exhaustion. Additionally the festival changed its re-entry policy, allowing people to exit back to their hotel rooms or nearby commercial areas to cool down. Eventually, with the daylight hours winding down and the many additional cooling stations that were brought in, the EMS units were able to clear the list of pending calls and the MCI was resolved. However several hours later, there was a (false) report of gunfire and a stampede broke out resulting in a new flood of patients. Fortunately, due to crowd control measures and on-site medical care, local hospitals were not inundated with patient transports.
Crowd Control
In many ways, event medicine is a preventive service and effective crowd control is a cornerstone. Mass gathering events ideally should have access points solely for entrance or exit, promoting a unidirectional flow of crowd members and dramatically reducing the risk of crowd convergence.
In 2010, the Love Parade in Germany had a stampede from crowd convergence because a tunnel provided the only means of entrance and exit to festival attendees. Other means of reducing stampedes include sectioning off areas of the main audience, a functioning public address system and protocols to stop artists performing should crushing or stampedes develop.
Another key element is adequate site access, not only for participants to leave, but also for EMS to enter. At this festival, there was an exclusive outer ring road designed for emergency response vehicles to allow more resources to come in and easy egress to transport patients out.
Conclusion
Provision of on-site physician-level medical care at mass gatherings has been shown to significantly reduce the number of patients requiring transport to hospital and therefore reducing the impact on local healthcare. The majority of injuries and medical complaints at a mass gathering can be effectively treated on scene, which reduces the number of hospital transports and event attendees utilizing local hospitals.
Nonetheless, local emergency departments should be made aware of events so they could prepare for patient surges as needed and plan accordingly. The on-site medical team cleared C-collars, sewed up lacerations, and reduced a shoulder dislocation to help decrease the burden on the local health infrastructure. In Britain, a common staffing model for fixed venue sporting events is one first aid personnel per 1,000 guests, one fully equipped ambulance per 5,000 guests, and an equipped medical facility for crowds over 25,000. The goal was to provide BLS care within 4 mins, ALS care within 8 mins, and transport to a hospital from a patient contact in 30 mins.
Prehospital physicians must both be flexible and be aware of all the resources at their disposal to provide appropriate care for all event goers. It is imperative that prehospital physicians have an opportunity to revise operational plans for events in order to properly prepare for and mitigate public health risks.
References:
Luk JH, Walsh B, Yasbin P. Safety and efficacy of prehospital diltiazem. West J Emerg Med. 2013;14(3):296-300. doi:10.5811/westjem.2011.8.6692
http://www.emdocs.net/em3am-heat-stroke
De Almeida, M., & Von Schreeb, J. (2019). Human Stampedes: An Updated Review of Current Literature. Prehospital and Disaster Medicine, 34(1), 82-88. doi:10.1017/S1049023X18001073
Yasser A. Alaska, Abdulaziz D. Aldawas, Nawfal A. Aljerian, Ziad A. Memish, Selim Suner, The impact of crowd control measures on the occurrence of stampedes during Mass Gatherings: The Hajj experience, Travel Medicine and Infectious Disease, Volume 15, 2017, Pages 67-70, ISSN 1477-8939
