Trauma: Primary & Secondary Survey (ATLS)
A boards-focused walkthrough of the ATLS primary (ABCDE) and secondary surveys, drilling next-best-step decisions for the immediate thoracic killers, hemorrhagic-shock classification, and the airway-before-everything priority rule.
ATLS: fastest killer first
ATLS organizes trauma care so the fastest killer is treated first. The primary survey (ABCDE) is a rapid, repeatable sweep to find and immediately treat life-threatening injuries—you never advance to the next letter until the current threat is controlled, and you re-survey (return to A) whenever the patient deteriorates. The order is Airway with C-spine protection, then Breathing, Circulation (with hemorrhage control), Disability, Exposure. Assessment and resuscitation happen simultaneously. Only after the primary survey and initial resuscitation do you perform the secondary survey: a head-to-toe exam plus AMPLE history to catch every remaining injury. On the boards, the next best step almost always follows ABCDE order—a threatened airway outranks a positive FAST, and controlling arterial hemorrhage outranks getting imaging.
- A – Airway + C-spine: A patient who speaks clearly has a patent airway. Indications for a definitive (cuffed, intubated) airway: apnea, GCS ≤ 8, inability to protect the airway, or impending obstruction (expanding neck hematoma, inhalation/facial burns).
- B – Breathing: Expose the chest and treat the injuries that kill by impairing ventilation—tension pneumothorax, open pneumothorax, massive hemothorax, flail chest with pulmonary contusion.
- C – Circulation: Two large-bore (14–16 g) IVs, control external bleeding with direct pressure, give warmed crystalloid then blood/balanced transfusion. Trauma hypotension is hemorrhagic until proven otherwise; also consider obstructive shock—cardiac tamponade and tension pneumothorax.
- D – Disability: GCS, pupil size/reactivity, lateralizing signs.
- E – Exposure/Environment: Fully undress the patient; then prevent hypothermia with warm fluids and blankets.
Vignette: After a high-speed MVC, a man is in severe respiratory distress with absent breath sounds and hyperresonance on the left, trachea deviated to the right, distended neck veins, and BP 78/40.
Dx: Tension pneumothorax—a clinical diagnosis. Do not wait for a chest X-ray.
Next step: Immediate needle decompression (5th intercostal space anterior/mid-axillary line, or 2nd ICS midclavicular line), followed by tube thoracostomy (chest tube), the definitive treatment.
Contrast: Distended neck veins + muffled heart sounds + hypotension (Beck triad) with equal breath sounds → cardiac tamponade → pericardiocentesis (temporizing) or pericardial window/thoracotomy (definitive).
Vignette: After blunt abdominal trauma, BP 82/50, HR 130. FAST shows fluid in Morrison's pouch (hepatorenal recess).
Dx: Hemoperitoneum causing hemorrhagic shock.
Next step: Exploratory laparotomy—a hemodynamically unstable patient with a positive FAST goes to the OR, not the CT scanner.
Key rule: Unstable → OR (use FAST/DPL if the source is unclear). Stable → CT abdomen/pelvis to characterize injury and permit non-operative management. In a stable patient, a negative FAST does not rule out injury (misses retroperitoneal and hollow-viscus injury) and does not replace CT.
Classes of hemorrhagic shock
| Feature | Class I | Class II | Class III | Class IV |
|---|---|---|---|---|
| Blood loss | <15% | 15–30% | 30–40% | >40% |
| Heart rate | <100 | 100–120 | 120–140 | >140 |
| Systolic BP | Normal | Normal | ↓ | ↓ |
| Pulse pressure | Normal/↑ | ↓ | ↓ | ↓ |
| Urine output | >30 mL/h | 20–30 | 5–15 | Negligible |
| Mental status | Slightly anxious | Mildly anxious | Anxious/confused | Confused/lethargic |
ABCDE — the primary survey order: Airway/C-spine, Breathing, Circulation, Disability, Exposure.
AMPLE — the trauma history taken during the secondary survey:
- A – Allergies
- M – Medications
- P – Past illnesses / Pregnancy
- L – Last meal
- E – Events / Environment (mechanism of injury)
"Blood on the floor and four more" — the sites of major occult hemorrhage that can cause shock: external blood loss ('the floor') plus chest, abdomen, pelvis/retroperitoneum, and long bones (thighs).
- Adjuncts to the primary survey: ECG, pulse oximetry, ABG, portable CXR and pelvic X-ray, FAST, plus urinary and gastric catheters.
- Secondary survey = full head-to-toe exam + AMPLE, performed only after ABCDE and initial resuscitation; includes log-roll to inspect the back/spine and a complete neuro exam.
- Foley is contraindicated if urethral injury is suspected—blood at the meatus, high-riding/boggy prostate, or scrotal/perineal hematoma; obtain a retrograde urethrogram first.
- Reassess (return to A) whenever vital signs deteriorate.
- Pelvic binder for an unstable pelvic fracture to tamponade venous bleeding; angioembolization for ongoing arterial bleeding.
Vignette: A trauma patient has GCS 6, a positive FAST, and an open femur fracture. BP 100/70, O2 sat 88% with gurgling respirations.
Priority/Dx: Threatened airway (GCS ≤ 8 plus secretions/inability to protect).
Next step: Secure a definitive airway (rapid-sequence intubation) with in-line C-spine stabilization first—Airway (A) precedes the positive FAST (C) and the dramatic fracture. GCS ≤ 8 alone mandates intubation.
Pearl: Address problems in strict ABCDE order, no matter how attention-grabbing a distal injury appears.
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