Emergency Medical Services: Systems, Triage, and Field Decisions
Core concepts
The EMS domain covers system design, medical direction, triage, transport decisions, and field protocols. Candidates should understand the difference between online (direct) and offline (indirect) medical direction, the role of EMS medical directors in protocol development and quality improvement, and the structure of triage and destination policies (trauma center levels, stroke and STEMI bypass, mass-casualty triage such as START).
Traps to watch
- Conflating scope of practice with certification. Scope is defined by state law and local protocol, not by national curriculum alone.
- Choosing "transport immediately" when the question describes a scene safety hazard. Scene safety precedes patient care.
- Missing the difference between lights-and-sirens transport and routine transport for stable patients.
- Forgetting documentation and handoff. SBAR or similar structured handoff is a tested concept.
- Confusing mass-casualty triage categories. Remember: immediate (red), delayed (yellow), minor (green), expectant/deceased (black/gray).
Worked example
A question describes a bus crash with 20 patients and asks how to prioritize. The trap is to treat the most visibly injured first. The correct approach is scene safety, then rapid triage using a validated system (START), tagging red patients for immediate transport and black for expectant care, and distributing patients across receiving facilities. Rule of thumb: in mass casualty, do the greatest good for the greatest number, not the sickest first.