The EMT's first task upon arrival at any scene is the scene size-up, beginning with body substance isolation (BSI) and personal protective equipment, then a quick assessment of hazards, the number of patients, and the need for additional resources. Once the scene is determined safe, the EMT proceeds to the primary assessment, a rapid evaluation designed to identify and immediately address life-threatening conditions. The traditional ABCDE framework (airway, breathing, circulation, disability, exposure) is now often preceded by an X for massive hemorrhage control when significant external bleeding is present. The disability component is typically measured using the AVPU scale (Alert, Verbal, Pain, Unresponsive) for quick use, while the Glasgow Coma Scale provides a more detailed assessment ranging from 3 (deep coma) to 15 (fully alert) based on eye opening (maximum 4), verbal response (maximum 5), and motor response (maximum 6).
After life threats are managed, the EMT gathers a focused or rapid medical history. Two key mnemonics organize this information: SAMPLE captures the broader history (Signs/symptoms, Allergies, Medications, Pertinent history, Last oral intake, Events leading up), while OPQRST is used specifically to characterize the patient's chief complaint (Onset, Provocation/palliation, Quality, Radiation, Severity, Time). Vital signs are obtained and compared against age-appropriate norms because pediatric and adult ranges differ substantially. Normal adult respiratory rate is 12–20 breaths per minute, heart rate is 60–100 beats per minute, and systolic blood pressure should be less than 120 mmHg. For children over one year, minimum acceptable systolic BP is estimated as \(70 + 2 \times \text{age in years}\) mmHg, while newborns have heart rates of 100–160 bpm and respiratory rates of 30–60, and children ages 1–12 breathe 15–30 times per minute.
The choice between a rapid trauma assessment and a focused assessment depends on mechanism of injury (MOI). Patients with significant mechanisms such as falls greater than 20 feet, high-speed vehicle collisions, ejection from the vehicle, or penetrating trauma to the torso or head warrant a rapid head-to-toe exam to identify hidden life threats. In contrast, patients with an isolated injury or no significant mechanism of injury receive a focused assessment centered on their chief complaint. In both cases, transport priority is determined by life threats found in the primary assessment, not by how dramatic an injury appears on the surface. Unresponsive patients with adequate breathing and no suspected spinal injury should be placed in the recovery position to protect the airway from aspiration.