What are the steps of the Advanced Trauma Life Support (ATLS) primary survey?

ATLS Primary Survey: The Systematic Approach to Trauma Assessment

The ATLS primary survey follows a systematic ABCDE approach (or x-ABCDE in the most recent 2025 update) to rapidly identify and treat life-threatening injuries in a prioritized sequence: Airway (with cervical spine protection), Breathing, Circulation, Disability (neurologic status), and Exposure/Environmental control. 1

The Sequential Steps

X - Control of Exsanguinating Hemorrhage (New Priority)

The 2025 ATLS 11th Edition now emphasizes immediate control of major external hemorrhage before proceeding with the traditional ABCDE sequence 1. This represents a critical update recognizing that massive external bleeding can kill faster than airway compromise.

• Apply direct pressure or tourniquets to control life-threatening external hemorrhage immediately
• This step precedes all other assessments when obvious major bleeding is present

A - Airway with Cervical Spine Protection

• Assess airway patency by asking the patient to speak (if conscious) or looking for signs of obstruction
• Look for: facial trauma, foreign bodies, vomitus, blood, broken teeth, or anatomic distortion
• Simultaneously maintain cervical spine immobilization in all blunt trauma patients 2, 3
• Establish definitive airway if needed (intubation or surgical airway)

Critical pitfall: Never hyperextend or rotate the neck during airway management in trauma patients.

B - Breathing and Ventilation

• Expose the chest completely to assess respiratory effort 4
• Count respiratory rate (normal 14-20; concerning if <10 or >29) 2, 5
• Administer supplemental oxygen immediately 4
• Inspect for: chest wall movement symmetry, use of accessory muscles, open wounds, flail segments
• Palpate for: subcutaneous emphysema, rib fractures, tenderness
• Percuss for: hyperresonance (pneumothorax) or dullness (hemothorax)
• Auscultate for: bilateral breath sounds
• Immediately treat life-threatening conditions: tension pneumothorax, open pneumothorax, massive hemothorax, flail chest

Ventilation strategy: Use protective ventilation with tidal volumes <6 ml/kg and moderate PEEP, even in patients with normal lungs, to prevent acute lung injury 2.

C - Circulation and Hemorrhage Control

• Palpate central pulses (carotid or femoral) for presence, rate, and quality 4
• Assess heart rate (normal <100 bpm; concerning if >120) 2
• Measure blood pressure - systolic BP <90 mmHg indicates Class III-IV hemorrhage 2
• Evaluate skin perfusion: color, temperature, capillary refill
• Establish two large-bore IV lines (or intraosseous access) 4
• Control internal hemorrhage sources

Hemorrhage classification (for 70 kg adult) 2:

• Class I: <750 ml (15% blood volume) - normal vital signs
• Class II: 750-1500 ml (15-30%) - tachycardia 100-120, normal BP
• Class III: 1500-2000 ml (30-40%) - tachycardia 120-140, decreased BP, anxious/confused
• Class IV: >2000 ml (>40%) - tachycardia >140, decreased BP, confused/lethargic

Resuscitation approach 1:

• Permissive hypotension (target SBP 80-90 mmHg) until hemorrhage controlled
• Limit crystalloids - avoid excessive fluid administration
• Early blood product transfusion for Class III-IV hemorrhage

D - Disability (Neurologic Assessment)

• Assess Glasgow Coma Scale (GCS) score 5, 4
• Rapid assessment: Alert, responds to Voice, responds to Pain, Unresponsive (AVPU)
• Check pupil size and reactivity bilaterally
• Assess for lateralizing signs or obvious spinal cord injury

Key threshold: GCS <14 significantly increases mortality risk and requires Level I trauma center transport 5.

E - Exposure and Environmental Control

• Completely undress the patient to identify all injuries 4
• Log-roll to examine the back (maintaining spinal precautions)
• Prevent hypothermia: cover with warm blankets, use warmed IV fluids, increase room temperature 2

Diagnostic Adjuncts During Primary Survey

Performed simultaneously with the ABCDE assessment 2, 3:

• Chest X-ray - identify pneumothorax, hemothorax, widened mediastinum
• Pelvic X-ray - detect unstable pelvic fractures (major hemorrhage source) 3
• Extended FAST (E-FAST) - detect free fluid in abdomen, pericardium, or hemothorax 3, 6
• Arterial blood gas - measure base deficit and lactate (sensitive markers of hemorrhagic shock) 3
• Point-of-care coagulation testing (TEG/ROTEM) if available 3

Important limitation: E-FAST has low sensitivity for detecting pelvic bleeding but adequate for excluding need for immediate laparotomy 3.

Critical Decision Points

Hemodynamically Unstable Patient

If positive FAST with hypotension: proceed directly to trauma laparotomy - do not delay for CT imaging 6, 2. Every 3 minutes spent in the emergency department increases death probability by 1% 6.

Hemodynamically Stable Patient

Proceed to secondary survey (complete head-to-toe examination) and CT imaging for definitive injury identification 2, 7.

Common Pitfalls to Avoid

1. Skipping steps: Studies show primary survey tasks are frequently omitted, particularly during overnight shifts and with burn injuries 8
2. Inadequate exposure: Failure to completely undress patients leads to missed injuries
3. Premature CT imaging: Unstable patients should not leave the resuscitation bay for imaging
4. Over-resuscitation: Excessive crystalloid administration worsens outcomes - use blood products early 1
5. Hyperventilation: Avoid hypocapnia (PaCO2 <27 mmHg) which worsens cerebral perfusion in traumatic brain injury 2
6. Delayed hemorrhage control: Time to operating room inversely correlates with survival in hemorrhagic shock 3

Performance Enhancement

Checklist use significantly improves ATLS adherence: Implementation of trauma checklists increases primary survey task completion (OR 2.66) and speeds vital sign assessment 4, 9. Standardized approaches with video review and feedback reduce physician variability and improve compliance to >90% 9.