General Clinical Assessment and Management

For initial lifesaving care, utilize the (MARCHE)2 protocol and CRESS assessment/intervention algorithms applicable for general and for CBRN casualties (see JTS Chemical, Biological, Radiological and Nuclear Injury Response Part I: Initial Response CPG).49  MARCHE2 is designed for point of injury care in the immediate aftermath of exposure to a chemical agent. Due to incubation periods for illness and delays in patient presentation, biological agent exposure may not be recognized in a time frame where the MARCHE2 paradigm is relevant. However, CRESS could be helpful for the evaluation of casualties from toxins which behave more like chemical agents than infectious diseases. As a result, CRESS toxin criteria were created to supplement the CRESS findings for chemical agents contained in the JTS Chemical, Biological, Radiological and Nuclear Injury Response Part I: Initial Response CPG (Table 4).      

As per JP 4-02, medical units must have a basic CBRN mass casualty plan that can be modified to meet varying situations, and each medical facility must be able to establish its own patient decontamination site. The vast majority of biothreat exposures would be able to be managed by standard DoD triage algorithms. However, medical units could consider layering on use of a sepsis screening tool (qSOFA or NEWS2), in the setting of a bioincident. See Appendix H for details of both scoring methods. 

Once the initial PROTECT tasks have been implemented and the casualty is stabilized, a detailed clinical assessment needs to occur as operational conditions allow (UNDERSTAND). It is critical to obtain an accurate chief complaint, history of the present illness with symptom attributes/progression, exposure history, past medical history, review of systems, and conduct a detailed physical exam (see Appendix G). Once this assessment is complete, providers should utilize syndromic characterization to generate a differential diagnosis. Understanding common endemic diseases in the area of operations and available diagnostics will also help reach a leading diagnosis. In addition, always inquire about other unit members who may be ill. 

Appendix A provides potentially diagnostic clinical clues (PDCs) in an algorithmic format to help narrow the differential diagnosis when epidemiologic clues are absent, and specific laboratory diagnostic tests are pending or unavailable. It is important to regularly reassess as the clinical picture may evolve and suggest an alternate diagnosis or confirm the initial leading diagnosis. It is also important to obtain technical reach-back early and as needed (Table 9). See JTS Telemedicine in the Deployed Setting, 19 Sep 2023 CPG50 for additional information for technical reach-back guidance.

Broad-spectrum empiric antimicrobial treatment should begin promptly based on the clinical scenario (MITIGATE) and should not be delayed pending confirmatory diagnostics. The early administration of appropriate antimicrobials is one of the most effective interventions to reduce mortality in patients with sepsis. Note that improved clinical outcomes from early, appropriate use of antimicrobials is not only limited to antibiotics for bacterial infections, but also applies to systemic viral51-53 fungal,54 and parasitic55 infections. Keep in mind, that in a bioweapon context, standard treatments may not work due to engineered resistance of pathogens. In addition, proper supportive care is extremely important to improve outcomes. Follow the latest Surviving Sepsis Guidelines/resources56 and the JTS Sepsis Management in Prolonged Field Care CPG.57 Specific pre-exposure prophylaxis (PrEP), post-exposure prophylaxis (PEP), and treatment recommendations for select biothreats are detailed in Appendix G with links to additional resources.