Scene Size-Up and Primary Assessment: The First Minutes of Every Call
The five parts of the scene size-up, the primary assessment from general impression to XABCDE, why massive bleeding now comes first in trauma, and the priority decision that ends it.
Practice this on a patient. The 60-second call is free, with no account.Start a free call
Every patient assessment starts the same way. Before you touch anyone, you size up the scene. Then, in the first minute or two with the patient, you do the primary assessment: find and fix whatever will kill them first. Everything else, the history, the secondary assessment and the vital signs, comes after. This is the part of the call that the NREMT patient assessment stations, and real patients, punish for skipping.
The scene size-up
The size-up has five parts. Texts and the NREMT skill sheets order them slightly differently (the NREMT sheet puts PPE first), so learn the order your program expects, and keep doing them for the whole call: a scene that was safe when you arrived can stop being safe.
| Part | What you are asking |
|---|---|
| Scene safety | Is it safe for me, my partner, bystanders and the patient? Traffic, fire, hazardous materials, unstable structures, weapons, animals, an angry crowd. If not, stay out until it is made safe or call for the people who can make it safe. |
| Standard precautions and PPE | What protection does this patient need from me and me from them? Gloves at minimum; eye protection, a mask or a gown when blood, fluids or an airborne illness are likely. |
| Mechanism of injury or nature of illness | What happened? For trauma, the forces involved and where they went. For a medical call, what the patient, family or scene tells you about the problem. |
| Number of patients | How many are there, and is it more than you can handle? Look beyond the obvious patient: the other car, the second floor, the bystander who is also sick. |
| Additional resources | Who else do I need now? More units, fire and rescue, law enforcement, air medical, a hazardous materials team, an advanced provider. Call early; you can always cancel. |
If the number of patients is more than your resources can treat, this is where a mass-casualty incident starts and triage replaces individual assessment.
Walk through START and JumpSTART triage
The primary assessment
The primary assessment finds immediate threats to life and treats them as you find them. It is short, it is done on every patient, and it ends with a decision about how urgent this patient is.
General impression
From the doorway or as you approach: age, sex, position, whether they look sick or not sick, and any obvious life threat such as massive bleeding. Experienced providers trust this impression and then confirm it.
Responsiveness
Check the level of responsiveness with AVPU: Alert, responds to Verbal stimulus, responds to Pain, or Unresponsive. Ask the chief complaint if the patient can answer. A patient who is unresponsive and not breathing, or only gasping, moves straight to a pulse check, and to CPR if there is no pulse.
X, A, B, C, D, E
| Step | What you check | What you do now |
|---|---|---|
| X: exsanguinating hemorrhage | Major external bleeding that will kill within minutes | Control it immediately: direct pressure, a tourniquet or wound packing as your protocol allows |
| A: airway | Is it open and clear? Sounds of obstruction, blood, vomit, a jaw that needs support | Position, suction, airway adjuncts; consider spinal motion restriction from the mechanism and the findings, per protocol |
| B: breathing | Rate, depth, effort, breath sounds, chest wall injury | Oxygen as indicated, assist ventilation if inadequate, seal an open chest wound |
| C: circulation | Pulse rate and quality, skin color, temperature and condition, other bleeding | Treat for shock, control remaining bleeding, keep the patient warm |
| D: disability | Level of responsiveness, pupils, gross movement and sensation | Note a change from baseline; check glucose where mental status is altered |
| E: exposure | Expose to find hidden injuries, then cover | Protect from cold and from bystanders |
Many curricula now teach life-threatening external bleeding first in a trauma patient, before the airway, because a patient can bleed to death faster than they suffocate. PHTLS uses this XABCDE order. Check the order your program and the NREMT trauma skill sheet expect, and use it consistently.
The priority decision
End the primary assessment by deciding whether this is a high-priority patient who needs rapid transport with treatment on the way, or a stable patient who can be assessed further on scene. Findings that usually make a patient high priority include:
- A poor general impression or altered responsiveness.
- An airway or breathing problem.
- Signs of shock, or bleeding that is hard to control.
- Chest pain with signs of poor perfusion, or a severe headache with altered mental status.
- A complicated childbirth.
- Uncontrolled pain or a mechanism that suggests serious hidden injury.
What comes next
For a responsive medical patient, the history comes next: the chief complaint, explored with OPQRST, and the SAMPLE history. For a trauma patient, the secondary assessment looks for injuries with DCAP-BTLS. Both are covered in their own guides in this library, and the NREMT medical and trauma assessment guides walk through the whole station in order.
Whether to restrict spinal motion is part of the trauma assessment and is decided by your protocol; the guide to the NEXUS criteria and the Canadian C-Spine Rule covers the common decision rules.
The short version
- Scene size-up: scene safety, PPE, mechanism or nature of illness, number of patients, additional resources. Keep doing it all call.
- Primary assessment: general impression, responsiveness and chief complaint, then X, A, B, C, D, E, treating each threat as you find it.
- Massive external bleeding comes first in trauma in many curricula.
- Finish with a priority decision: rapid transport, or more assessment on scene.
- Then the history (OPQRST, SAMPLE) or the secondary assessment (DCAP-BTLS).