Anthrax Crisis Standards of Care

On December 4, the Centers for Disease Control and Prevention (CDC) published Clinical Framework and Medical Countermeasure Use During an Anthrax Mass-Casualty Incident.  The framework provides updated recommendations for anthrax diagnosis and treatment, specifically addressing crisis standards of care.  During a mass-casualty incident involving the dissemination of B. anthracis, demand will quickly exceed available healthcare resources, and the shift to crisis standards of care represents a fundamental change in the way medical care is delivered.  In emergency situations with relatively limited resources, healthcare professionals will need to prioritize allocation of limited time, personnel, medications, medical supplies and equipment to those who stand to benefit most.

The new recommendations build upon the 2014 CDC guidelines for prevention and treatment of anthrax to address situations where increased demand for medical care will exceed available healthcare resources.  The crisis standards of care guidelines, compiled at a March 2014 meeting of 102 subject matter experts, represent evidence-based best practices to efficiently address anthrax mass-casualty scenarios.  The clinical framework addresses four specific decision points in the clinical care of anthrax cases that would likely be impacted by limited resources.

  • Due to the high incidence of meningitis in anthrax patients, the first decision point discusses “diagnostic evaluation of anthrax meningitis” in order to determine the appropriate approach to antimicrobial therapy.
  • The second decision point helps determine appropriate antimicrobial treatment options based on their availability.
  • Considering the significant pathologic effect of B. anthracis exotoxins, the third decision point addresses use of antitoxins as adjuncts to antimicrobial therapy.
  • The fourth decision point covers identifying and draining accumulated pleural, pericardial and peritoneal fluid, which is associated with improved outcomes.

The challenges associated with each decision point and the evidence supporting the associated crisis standards of care are discussed in depth.  In addition to the crisis standards of care, the report provides conventional and contingency standards of care for comparison.  The guidance also addresses the challenges posed by pregnant and lactating women and pediatric cases, determining that both of these types of cases should be considered as high a priority as non-pregnant adults while noting that they will likely require additional monitoring and specialized care.  Finally, the report identifies areas for future research, specifically assessment of potential clinical markers to better assess disease progression in anthrax cases to support clinical care decision-making.

These guidelines provide data-driven recommendations for the dire situation where demand for life-saving therapies exceeds supply.  In the absence of a situation requiring a move to contingency or crisis standards of care, all safe and effective therapies should be used in every patient who could potentially benefit from them, even if the prognosis is relatively poor.  In a situation in which limited supplies of certain medications such as toxin-directed antibodies are insufficient, however, these scarce resources should ideally be reserved for patients who will unequivocally benefit from them.  The guidelines delineate in which situations certain therapeutic actions are appropriate and provide the treating clinician with a framework with which to provide optimal care. 

The new CDC guidance is designed to be used in preparing response protocols for or in responding to the "exhaustion (or impending exhaustion) of the capability to provide conventional standards of care," but it "does not address primary triage decisions, anthrax post-exposure prophylaxis (PEP), hospital bed or workforce surge capacity, or the logistics of dispensing MCMs."  These recommendations highlight that resource deficiencies may not affect all aspects of clinical response simultaneously, so crisis standards of care may be applied to individual aspects of diagnosis and treatment as necessary.  The guidance also caveats that clinical protocols should shift back to conventional standards of care as soon as possible.  

In the event of a mass-casualty anthrax incident, the updated CDC guidance provides clinicians with a standardized methodology for optimizing limited resources to achieve the overall greatest impact on the affected population under sub-optimal conditions.