Prehospital Academy Lesson 10.1
An EMS call is more than a simple response to an emergency; it is a structured, multi-phase operation that requires both rigid adherence to sequence and fluid clinical adaptability. While every call follows a general progression from dispatch to the final handover of care, the successful EMT must navigate these phases with an understanding of both operational logistics and high-stakes clinical decision-making. This companion explores the seven core clinical phases of a call while providing the broader operational framework necessary for professional practice.
The Seven Clinical Phases of EMS Patient Care
The lecture identifies seven distinct phases that define the patient-provider interaction. Understanding these phases allows the provider to mentally "gate" their priorities, ensuring that critical tasks are completed before moving to the next stage of the encounter.
Dispatch Phase: The initial point of contact where the provider receives essential data—location, nature of call, and potential hazards. This phase begins the process of "mental modeling," where the crew prepares their equipment and strategy based on the dispatch information.
Arrival Phase: Often referred to as the "Scene Size-Up," this phase is centered on safety and resource management. The provider must evaluate scene safety, the mechanism of injury (MOI) or nature of illness (NOI), and the need for additional resources (e.g., ALS, Fire, Police).
Primary Assessment: The first clinical contact where life-threats are identified and managed. While traditionally following the ABC (Airway, Breathing, Circulation) sequence, as noted in the lecture, this may shift to CAB if massive hemorrhage is present.
Transport Decision: A pivotal moment where the provider determines the urgency of the patient's condition (e.g., "Load and Go" vs. "Stay and Play") and identifies the most appropriate receiving facility based on specialty needs like trauma, stroke, or cardiac care.
Secondary Assessment and History: A deeper dive into the patient's condition, including a physical exam and a detailed history (using mnemonics like SAMPLE and OPQRST). This phase is often where the definitive clinical picture is formed.
Reassessment: The ongoing process of monitoring the patient for changes. Critical patients are typically reassessed every 5 minutes, while stable patients are reassessed every 15 minutes. This ensures that interventions are effective and no new issues have developed.
Patient Handover: The final clinical phase where responsibility for the patient is transferred. This is a high-risk period for medical errors, requiring clear, structured communication to ensure the continuity of care.
Value-Add: The Operational Framework (The 9 Phases)
While the clinical phases focus on the patient, the "Ambulance Lifecycle" includes operational phases that occur before and after the patient encounter. Standard EMS education recognizes a nine-phase model for ambulance operations:
Preparation: Ensuring the vehicle is fueled, stocked with oxygen and medications, and all equipment (like the AED and monitor) is functional. This occurs before the call is even received.
Dispatch: As discussed, the relay of information to the crew.
En Route: Driving to the scene. This is often the most dangerous part of the call for the provider, requiring high-level situational awareness and defensive driving.
Arrival: Managing the scene and establishing patient contact.
Transfer to Ambulance: Safely moving the patient using appropriate lifting techniques and securing them for transport.
En Route to Facility: The transport phase where clinical care continues in the back of the moving unit.
At Receiving Facility (Delivery): Completing the handover and moving the patient to the hospital bed.
En Route to Station: The phase after delivery but before being "back in service," often used for cleaning and initial documentation.
Post-Run: The final restocking, deep cleaning, and completion of the Patient Care Report (PCR).
Clinical Deep-Dive: Structured Handover (SBAR)
The "Handover Phase" mentioned in the lecture is one of the most critical transitions in healthcare. To prevent the loss of vital information, EMS providers often utilize the SBAR framework:
Situation: Who are you, and why are you here? (e.g., "This is a 65-year-old male with chest pain.")
Background: What led to this? (e.g., "Patient has a history of CAD and started having pain 20 minutes ago while mowing.")
Assessment: What did you find? (e.g., "Vitals are stable, but the 12-lead shows ST-depression in leads V4-V6.")
Recommendation: What did you do, and what do they need next? (e.g., "We gave 324mg Aspirin and 0.4mg Nitro. He needs an immediate evaluation by the cardiac team.")
Critical Thinking Questions
During the Dispatch phase, you are told you are responding to a "possible psychiatric emergency." How should this information influence your "Arrival Phase" differently than if the dispatch was for "chest pain"?
The lecture notes that the order of the Primary Assessment can change (e.g., checking circulation before airway). Describe a specific trauma scenario where starting with "C" (Circulation) is clinically superior to starting with "A" (Airway).
Why is the "Preparation Phase" considered the most important phase for provider safety, even though it occurs before any emergency exists?
During the "Transport Decision" phase, you have a patient with a suspected stroke. The nearest hospital is 5 minutes away, but the Comprehensive Stroke Center is 20 minutes away. What factors must you weigh to make the correct transport decision?
If a provider fails to perform a thorough "Reassessment" during a 30-minute transport of a "stable" patient, what specific clinical risks (latent errors) might be missed?