Chemical, biological, radiological, and nuclear (CBRN) events occur often in concert with traumatic injuries; however, a large majority of CBRN literature and research frequently exclude the trauma perspective (Expert Opin Ther Pat 2016;26:1431-47; Expert Opin Ther Pat 2016;26:1399-1408). This article supposes that CBRN events do not predominately occur in isolation, obligating further discussion to approach CBRN management through the lens of trauma. Toxic industrial chemicals (TICs), biological agents with an infectious prodrome, radiological exposures from possible dirty bombs, nuclear detonation, and nuclear power plant disasters result in different forms of contamination (external and/or internal) in the setting of trauma (Int J Radiat Biol 2017;93:870-84; Int J Radiat Biol 2017;93:851-69).
Emergency medical services (EMS) and hospital emergency medical departments will be the first to encounter these CBRN patients, which substantiates the need for effective and efficient CBRN tools. These tools include personal protection equipment (PPE) as well as efficient and accurate methods to diagnose, triage, and manage complex patients in resource-limited settings. Despite the demands that these events place on our health care system, few hospitals are sufficiently prepared to cope with the combination of patient volume, efficient decontamination, and resource surge demand. If this was not challenging enough, traumatic injuries in addition to a CBRN event further complicate the process of triage, decontamination, and patient movement through the system with ongoing diagnosis and management.
The ongoing SARS-CoV-2 (COVID-19) pandemic revealed issues with surge planning for patients and demand for oxygen supply, PPE, ventilators, personnel, and morgue space. CBRN events become even more acutely disruptive to hospitals and communities relative to the slower surge seen in the COVID-19 pandemic, which requires urgent attention to address these risks and others that would overwhelm available medical infrastructure.
Triage, decontamination, and PPE
Effective triage is paramount to the management of CBRN events and should be performed at every echelon of medical care with redundancy. In CBRN events, triage begins alongside the demarcation of hot, warm, and cold zones. The hot zone is the site of initial exposure where patients are first categorized into color codes of black (expired), red (critical/non-ambulatory), yellow (delayed/non-ambulatory), and green (ambulatory) and moved to the warm zone for decontamination (Emerg Med J 2008;25:108-12). Ingress and egress points are established to control movement into the warm zone where patients are again categorized, decontaminated, stabilized, and transferred to the cold zone for definitive care, if possible (Expert Opin Ther Pat 2016;26:1431-47; Expert Opin Ther Pat 2016;26:1399-1408). Of note, contaminated ambulatory patients may self-present to a hospital for initial decontamination and medical management outside the hot and warm zone, transforming the ED and ambulance bay into a warm zone within the cold zone. In the hot zone, patients are triaged by first responders donned in task-limiting, mission-oriented protective posture (MOPP) gear using triage tools like START (Simple Triage And Rapid Treatment) or SALT (Sort, Assess, Life-saving interventions, Treatment and Transport) (Emerg Med J 2008;25:108-12; Eur J Anaesthesiol 2002;19:166-9). Airway management is limited to opening the airway and possibly inserting a laryngeal mask airway (Anesthesiology 2004;100:260-6).
Unlike CBRN events in isolation, combined trauma and CBRN require expedient interventions without universal delay for decontamination. In radiological exposures, treatment should not be delayed for decontamination when the patient has life-threatening injuries in the hot and warm zone. Patients with nuclear or radiological exposure can safely relocate for definitive care following removal of their contaminated clothing and simple covering of contaminated wounds followed by cocooning patients in a sheet for transportation (Int J Radiat Biol 2017;93:870-84; Int J Radiat Biol 2017;93:851-69). Chemical exposure decontamination should occur for skin contact; however, chemical vapor exposure relies on early mobilization away from the source rather than decontamination (Expert Opin Ther Pat 2016;26:1431-47; Expert Opin Ther Pat 2016;26:1399-1408). Methods of chemical agent decontamination include physical removal, chemical deactivation, and biological deactivation of the compound. For example, M291 resin is effective at decontamination of chemical agents (asamonitor.pub/3rnstTk). Biological exposure decontamination occurs in the warm zone using ozone, chlorine dioxide, ethylene oxide, and paraformaldehyde. However, the best universal liquid decontamination is 0.5% hypochlorite solution (diluted bleach) (asamonitor.pub/3qmecqy).
PPE requirements are dependent on the type of CBRN exposure, ranging from MOPP gear for chemical and biological exposures to standard precautions with face and eye protection with radiological and nuclear exposures (Figure). PPE proved to be in limited supply during the COVID-19 pandemic surges, and this is likely more limited for specialized MOPP gear and standard PPE in a CBRN mass casualty incident. This would further create demand pressure on the existing standard PPE for warm and cold zones.
Chemical exposures can include agents from industrial accidents such as hydrogen cyanide and other TICs to intentional attacks with sarin and Novichok agents. Medical personnel must remain vigilant and aware of these agents to avoid misdiagnosis and a delay in care. Biological exposures may present in concert with traumatic injuries and distract from identifying concomitant exposure to Bacillus anthracis (anthrax), Yersinia pestis (plague), Brucella suis (brucellosis), Coxiella burnetii (Q fever), or Rickettsia prowazekii (typhus) (asamonitor.pub/3qmecqy).
MOPP gear protects first responders in the hot zone; however, it significantly limits their function to establish intravenous access or perform invasive airway interventions. MOPP gear also predisposes first responders to a risk of overheating and exhaustion, while CBRN and trauma events demand expedient triage, control of massive hemorrhage, and mobilization forward to the warm zone (with the exception of radiologic and nuclear exposures) (asamonitor.pub/3rgU1JN).
Medical management of hospitalized CBRN patients with trauma involves decontamination of wounds from chemical, biological, radiological, and nuclear exposures. It also demands an in-depth understanding of specific goal-directed medical management depending on the type of exposure and the impact on necessary surgeries. Chemical and biological agents present with vague symptoms that frequently cause misdiagnosis (Expert Opin Ther Pat 2016;26:1431-47; Expert Opin Ther Pat 2016;26:1399-1408). Irrespective of correct identification of exposure, patients need intensive care and appropriate administration of countermeasures and antidotes. Radiological and nuclear exposures present very different challenges to medical management based on the effect of the exposure time to emesis, the dose delivered, radioisotope present, and if externally and/or internally exposed (Int J Radiat Biol 2017;93:870-84; Int J Radiat Biol 2017;93:851-69). Radiological exposure depends on the type of ionizing radiation (alpha, beta, or gamma) and its depth of tissue damage. Although gamma ionizing radiation is the most discussed, accidental ingestion of either alpha or beta can cause significant morbidity and mortality (Int J Radiat Biol 2017;93:870-84; Int J Radiat Biol 2017;93:851-69). Such patients suffer from acute radiation sickness, bone marrow suppression, gastrointestinal effects, and cutaneous manifestations. These have major implications on wound healing and any pending trauma-related surgeries.
CBRN patients can present from many different scenarios and overwhelm most hospital systems due to under-preparedness. We only need to look at our own experience from the protracted COVID-19 pandemic and its impact on hospital operations. By comparison, a CBRN event would cause an even more abrupt and drastic interruption to hospital systems. A combined CBRN and trauma event would create an acute spike in patients and demand for resources without the benefit of prolonged response. Hospitals need tools and training to adequately prepare to effectively manage CBRN exposures and concurrent trauma while keeping their staff protected. One of the best mechanisms for ensuring readiness is to formulate hospital and community-based disaster plans and perform large-scale simulations as a hospital in partnership with EMS, police departments, fire departments, and local government entities (asamonitor.pub/3GwyKlN). This establishes a relationship and communication between departments, and it identifies key players, potential gaps in knowledge or preparedness, and contingency planning for equipment and staffing – all aspects of medical management for the traumatically injured CBRN patient that anesthesiologists should be familiar with.