Patient Assessment: Scene Size-Up and Primary Survey

Patient Assessment: Scene Size-Up and Primary Survey

Every call begins before you touch the patient. The first two phases of the patient assessment sequence — the scene size-up and the primary survey — exist for one purpose: identify and correct threats to life, yours and the patient's, as fast as possible. NREMT skill sheets evaluate these phases separately and penalize any critical failure. Learn them in order; practice them until the sequence is automatic.

Scene Size-Up

BSI / PPE. Before you exit the unit, don your body substance isolation (BSI) gear. At minimum, this means gloves and eye protection. If blood splatter, airway management, or an infectious disease risk is likely, add a mask and gown. PPE is not optional — it is the first step, every time, on every call. No gloves means an automatic critical failure on the NREMT skill sheet.

Scene safety. Scan the scene continuously. Ask: Is it safe to enter? Look for traffic, fire, downed power lines, structural instability, violent bystanders, or hazardous-materials placards. If a hazmat placard is visible, do not enter the hot zone — call for a hazmat team and establish a perimeter. Your job is emergency medical care; you cannot provide it if you become a victim. Scene safety is never a one-time check; reassess throughout the call.

Mechanism of injury (MOI) / Nature of illness (NOI). For trauma, identify the forces involved — motor vehicle crash, fall, penetrating injury. MOI guides your index of suspicion for hidden injuries. For a medical patient, determine NOI by speaking with the patient, family, or bystanders. MOI/NOI shapes every decision that follows.

Number of patients. Count all patients immediately. If you have more patients than your crew can manage safely, activate your mass-casualty incident (MCI) plan and request additional resources before beginning individual care. On a multiple-casualty scene, briefly survey the area before committing to the first patient you see.

Additional resources. Based on your size-up, call early for what you need — advanced life support (ALS) intercept, additional ambulances, law enforcement, fire suppression, or utility company response. Early activation saves critical minutes.

The Primary Survey (XABC)

The primary survey is a rapid, structured scan to find and treat immediate life threats. The modern mnemonic taught in many fire-based EMS systems is XABC: Exsanguinating hemorrhage, Airway, Breathing, Circulation, Disability. (Some curricula use ABCDE; confirm the format required by your program and state.)

X — Exsanguinating Hemorrhage. Before anything else, control massive, life-threatening external bleeding. Arterial hemorrhage from an extremity can kill in minutes. Apply a tourniquet for extremity arterial bleeds; use wound packing and direct pressure for junctional or truncal wounds. Do not skip past a spurting wound to assess the airway.

A — Airway. Determine whether the airway is open. In an unresponsive patient, use the head-tilt chin-lift (no trauma) or jaw-thrust (suspected spinal injury) to open the airway. Look and listen for air movement. Suction if secretions or vomit are present. Insert an oropharyngeal airway (OPA) if the patient is unconscious and has no gag reflex, or a nasopharyngeal airway (NPA) if a gag reflex is present.

B — Breathing. Look, listen, and feel for breathing. Count rate and assess adequacy — are respirations too slow, too fast, or too shallow? Apply high-flow oxygen via non-rebreather mask for most serious trauma or medical patients, or assist ventilations with a bag-valve mask (BVM) if breathing is inadequate. Seal an open chest wound with a vented chest seal if indicated.

C — Circulation. Check for a pulse (carotid in unresponsive adults, brachial in infants). Assess skin color, temperature, and condition for signs of shock. Control any remaining significant external bleeding with direct pressure or hemostatic dressings. If there is no pulse, begin CPR.

D — Disability. Rapidly assess level of consciousness using the AVPU scale: Alert, responds to Verbal stimuli, responds to Painful stimuli, Unresponsive. Check pupils with a penlight — are they equal and reactive? Note any obvious motor deficit. This is a 15-second check, not a full neurological exam.

Putting It Together: Forming a General Impression

Simultaneous with the XABC, form a general impression — the patient's apparent age, sex, and how sick or injured they appear. This global read helps you set urgency and decide on rapid transport versus on-scene treatment.

Special Situations

• Combative patient: Ensure law enforcement is on scene before approaching. Do not restrain without appropriate assistance. Your safety comes first.
• Pediatric patients: Use length-based resuscitation tape (such as a Broselow tape) for weight estimation. Normal vital-sign ranges differ by age.
• Hazmat scenes: Identify the material using placards, the Emergency Response Guidebook (ERG), or CHEMTREC before committing personnel. No EMS responder operates in the hot zone without proper training and equipment — Hazmat Operations certification is the minimum.

Safety Reminders

• PPE on before every patient contact.
• Reassess scene safety continuously — conditions change.
• Never enter a hazmat hot zone as a standard EMT.
• Tourniquet application is a life-saving intervention, not a last resort for arterial extremity bleeds.
• When in doubt about scene safety, stage and wait for the appropriate resource.