Prehospital Academy Lesson 43.3
EMS MCI Response
In a Mass Casualty Incident (MCI), the standard of care shifts from clinical individualism to a utilitarian framework: "the greatest good for the greatest number." This lecture covers the organizational structure of the Incident Command System (ICS), the physiological triggers of rapid triage algorithms, and the ethical weight of resource allocation in high-stress environments.
The Utilitarian Foundation of Triage
Under normal circumstances, EMS operates under Deontological Ethics, where the duty is to provide the best possible care to the individual patient at hand. In an MCI, resources are overwhelmed, necessitating a shift to Utilitarianism. Triage is the clinical mechanism of this shift, sorting patients based on their likelihood of survival with immediate intervention versus the cost of resources they would consume.
START Triage: Adult Physiological Markers
The Simple Triage and Rapid Treatment (START) system is designed for speed, allowing a single provider to triage a patient in under 30 seconds. The assessment follows the RPM mnemonic:
R - Respirations: If the patient is not breathing, open the airway. If they remain apneic, tag BLACK (Deceased). If they breathe >30 RPM, tag RED (Immediate).
P - Perfusion: Assess for a radial pulse or capillary refill. If the radial pulse is absent or cap refill is >2 seconds, tag RED (Immediate). This indicates compensated or decompensated shock.
M - Mental Status: Assess the ability to follow simple commands ("Squeeze my hands"). Failure to follow commands indicates altered mental status, likely from hypoxia or shock, and warrants a RED (Immediate) tag.
Patients who are "30-2-Can Do" (Resps <30, Cap <2, Can follow commands) are tagged YELLOW (Delayed). Those who can walk are tagged GREEN (Minor).
JumpSTART: Pediatric Physiological Adaptation
Children require a different triage logic because their primary cause of cardiac arrest is typically respiratory failure, not primary cardiac events. The JumpSTART algorithm accounts for this:
The Apneic Child: Unlike adults, if a child is not breathing after an airway maneuver, the provider checks for a peripheral pulse. If a pulse is present, the provider delivers 5 rescue breaths. This "jumpstart" may restore spontaneous respirations. If the child remains apneic after the breaths, they are tagged BLACK.
Respiratory Rate: The range for "normal" is wider; a child is tagged RED if their respiratory rate is <15 or >45 RPM.
SALT Triage: The Modern All-Hazards Standard
The SALT (Sort, Assess, Lifesaving Interventions, Treatment/Transport) algorithm is the latest evidence-based standard. It improves upon START by introducing "Global Sorting":
Sort: Use voice commands to sort the "walking" (Priority 3) and the "wavers/purposeful movers" (Priority 2). Responders immediately focus on those who are not moving (Priority 1).
Lifesaving Interventions (LSI): Unlike START, SALT encourages brief interventions during triage, such as applying a tourniquet for catastrophic hemorrhage or performing a needle chest decompression for tension pneumothorax.
ICS Organization: Scene Management Roles
To prevent "freelancing" and manage the chaos of an MCI, the Incident Command System (ICS) defines clear roles within the Medical Branch:
Triage Officer: Oversees the initial sorting of all patients and ensures everyone is tagged.
Treatment Officer: Establishes the Treatment Area (Casualty Collection Point) and oversees the stabilization of patients based on their priority.
Transport Officer: Manages the flow of ambulances and communicates with the Medical Communications Coordinator to ensure hospitals are not "over-triaged" (overwhelmed with patients beyond their capacity).
Staging Officer: Ensures that arriving units do not block access and are ready for immediate deployment.
Critical Thinking Questions
In the **START** system, a patient with a respiratory rate of 28, a present radial pulse, but an inability to follow commands is tagged RED. What is the physiological rationale for this?
Why does the **JumpSTART** system include 5 rescue breaths for an apneic child with a pulse, while the adult **START** system does not?
Explain the concept of "Over-Triage" in an MCI. How does a failure in the Transport Sector lead to poor patient outcomes at the regional hospital level?
During **SALT** triage, you encounter a patient with an arterial bleed in their leg. Do you tag them and move on, or do you intervene? Justify your answer based on the SALT framework.
What are the forensic and investigative reasons for leaving **Black Tagged** victims exactly where they were found during the triage phase?