Trauma & ATLS Primary Survey

Trauma is the leading cause of death in the first four decades of life, and a disproportionate share of those deaths are preventable. The Advanced Trauma Life Support (ATLS) framework gives a reproducible, priority-driven method — treat the greatest threat to life first — so that resuscitation begins before a full diagnosis is reached. This note covers the primary survey (ABCDE), adjuncts (FAST, X-rays), haemorrhage control, the lethal chest injuries, massive transfusion, and damage-control principles.

The trimodal distribution of death

Understanding when trauma kills explains why ATLS is structured the way it is.

Peak	Timing	Cause of death	Influenced by
First (immediate)	Seconds–minutes	Major brain/brainstem/high spinal cord injury, aortic/cardiac rupture	Prevention (helmets, seatbelts), not treatment
Second (early)	Minutes–hours	Subdural/extradural haematoma, haemo/pneumothorax, ruptured spleen/liver, pelvic fracture, multiple injuries with blood loss	The "golden hour" — ATLS targets this peak
Third (late)	Days–weeks	Sepsis, multi-organ dysfunction syndrome (MODS)	ICU care, source control

High-yield: ATLS is designed primarily to reduce second-peak deaths — the "golden hour." These are the potentially preventable deaths from haemorrhage and airway/breathing problems.

Core principles

1. Treat the greatest threat to life first.
2. The lack of a definitive diagnosis should never delay life-saving treatment.
3. A detailed history is not essential to begin evaluation (AMPLE history is taken later: Allergies, Medications, Past illness/Pregnancy, Last meal, Events/Environment).
4. Reassess constantly — if the patient deteriorates, start again at A.

Primary survey — the ABCDE

The primary survey identifies and simultaneously treats immediately life-threatening conditions. In a single rescuer the sequence is strictly ordered; in a trauma team, steps occur in parallel.

A → B → C → D → E, with C-spine protection running alongside A.

A — Airway with cervical spine protection

• Assess: ability to speak (a talking patient has a patent airway and adequate cerebral perfusion). Look for stridor, gurgling, hoarseness, facial/laryngeal trauma, foreign body.
• Assume a cervical spine injury in any blunt trauma above the clavicle, multisystem trauma, or altered consciousness → maintain in-line immobilisation (rigid collar + blocks + tape, or manual in-line stabilisation during intubation).
• Interventions, escalating: chin-lift/jaw-thrust → suction → oropharyngeal (Guedel) airway (only if unconscious, no gag) or nasopharyngeal airway → definitive airway = cuffed tube in the trachea.

High-yield: A GCS ≤ 8 mandates a definitive (cuffed) airway — "GCS 8, intubate." Rapid-sequence induction (RSI) is the standard method. Indications for surgical airway (cricothyroidotomy): inability to intubate due to massive facial trauma, laryngeal injury, or oedema. Surgical cricothyroidotomy is contraindicated/avoided in children < 12 years (needle cricothyroidotomy preferred) due to cricoid cartilage importance.

B — Breathing and ventilation

A patent airway does not guarantee ventilation. Expose the chest, look-listen-feel, count the respiratory rate, and pulse-oximetry. The primary survey must detect and treat the six immediately life-threatening chest conditions (mnemonic ATOM-FC):

• Airway obstruction
• Tension pneumothorax
• Open pneumothorax (sucking chest wound)
• Massive haemothorax
• Flail chest (with pulmonary contusion)
• Cardiac tamponade

High-yield: Tension pneumothorax is a clinical diagnosis — do NOT wait for a chest X-ray. Signs: respiratory distress, tracheal deviation away, absent breath sounds + hyperresonance on the affected side, distended neck veins, hypotension. Immediate treatment = needle decompression then chest tube.

Needle decompression landmark: traditionally 2nd intercostal space, mid-clavicular line; current ATLS (10th edition) also accepts the 5th ICS, anterior to mid-axillary line because chest-wall thickness in adults often exceeds standard needle length anteriorly. Definitive treatment is always a chest tube (tube thoracostomy).

C — Circulation with haemorrhage control

Haemorrhage is the leading cause of preventable death after injury. Assess: level of consciousness, skin colour/temperature, pulse, and capillary refill. Hypotension after trauma is haemorrhagic until proven otherwise.

Action steps: apply direct pressure to external bleeding → two large-bore (14–16 G) peripheral IV cannulae → send blood for cross-match → begin balanced resuscitation → identify the source.

The five sites of major occult blood loss ("blood on the floor and four more"): external/floor, chest, abdomen, pelvis/retroperitoneum, long bones (thigh).

Classes of haemorrhagic shock (ATLS)

Parameter	Class I	Class II (mild)	Class III (moderate)	Class IV (severe)
Blood loss	<15% (<750 mL)	15–30% (750–1500 mL)	30–40% (1500–2000 mL)	>40% (>2000 mL)
Heart rate	<100	100–120	120–140	>140
Blood pressure	Normal	Normal	Decreased	Decreased
Pulse pressure	Normal/↑	Decreased	Decreased	Decreased
Respiratory rate	14–20	20–30	30–40	>35
Urine output	>30 mL/h	20–30 mL/h	5–15 mL/h	Negligible
CNS/mental status	Slightly anxious	Mildly anxious	Anxious, confused	Confused, lethargic

High-yield: The earliest reliable sign of haemorrhagic shock is tachycardia and a narrowed pulse pressure (from rising diastolic due to catecholamine-driven vasoconstriction). Hypotension is a LATE sign — blood pressure falls only after ~30% loss (Class III). Do not be reassured by a normal systolic BP.

Fluid resuscitation: ATLS recommends an initial bolus of 1 L of warmed isotonic crystalloid (Ringer's lactate preferred) in adults (20 mL/kg in children). Patients who do not respond or transiently respond need blood. The modern emphasis is on early blood products and permissive hypotension (target systolic ~80–90 mmHg until surgical control) in penetrating trauma without head injury, to avoid clot disruption and dilutional coagulopathy.

D — Disability (neurological)

• Rapid assessment: GCS, pupil size and reactivity, lateralising signs.
• The Glasgow Coma Scale: Eye (4) + Verbal (5) + Motor (6), range 3–15. Severe head injury = GCS 3–8; moderate 9–12; mild 13–15. Best motor response is the strongest prognostic component.
• A declining GCS or unequal pupils suggests an expanding intracranial lesion → urgent CT head and neurosurgical referral. Remember non-traumatic causes of altered sensorium too: hypoglycaemia, hypoxia, alcohol, drugs.

E — Exposure and Environment

• Fully undress to find all injuries (log-roll to inspect the back, perform per-rectal exam where indicated), then prevent hypothermia — warm blankets, warmed fluids, warm room.

High-yield: The "lethal triad" / "triad of death" in trauma = hypothermia + acidosis + coagulopathy. Each worsens the others; preventing hypothermia in step E is therefore part of haemorrhage management, not an afterthought.

Adjuncts to the primary survey

These run alongside resuscitation, not after it: ECG monitoring, pulse oximetry, capnography, urinary and gastric catheters (a nasogastric tube is contraindicated with suspected cribriform-plate/basal-skull fracture — use orogastric instead), ABG/lactate, and imaging.

Standard trauma X-rays

The three classic ATLS radiographs in blunt trauma: chest, pelvis, and (historically) lateral C-spine — though CT increasingly replaces plain C-spine films.

FAST scan

FAST = Focused Assessment with Sonography for Trauma. A bedside ultrasound to detect free fluid (blood) in dependent spaces. It answers one question: is there free fluid? — not the organ injured.

The four classic FAST windows:

1. Right upper quadrant (hepatorenal recess / Morison's pouch) — most sensitive for free fluid in the supine patient.
2. Left upper quadrant (perisplenic / splenorenal).
3. Pelvis (rectovesical pouch / pouch of Douglas).
4. Pericardial / subxiphoid view (for tamponade).

eFAST (extended FAST) adds bilateral thoracic views to detect pneumothorax and haemothorax.

High-yield: FAST is fast, repeatable, non-invasive, and bedside — ideal for the haemodynamically unstable blunt trauma patient. A positive FAST in an unstable patient → straight to laparotomy. FAST is poor at detecting hollow-viscus, retroperitoneal, and diaphragmatic injuries and cannot quantify or grade solid-organ injury — that needs CT (used in stable patients).

DPL vs FAST vs CT

Modality	Best use	Strength	Weakness
DPL (diagnostic peritoneal lavage)	Unstable, equivocal FAST	Very sensitive for haemoperitoneum; detects hollow-viscus injury	Invasive, over-sensitive, largely replaced
FAST	Unstable blunt trauma	Bedside, fast, repeatable, no radiation	Operator-dependent; misses retroperitoneum/hollow viscus
CT abdomen (contrast)	Haemodynamically stable patient	Grades solid-organ injury, sees retroperitoneum	Requires transport — unsafe if unstable; radiation

A positive DPL = aspiration of ≥10 mL gross blood, or lavage red cells >100,000/mm³, white cells >500/mm³, or presence of bile/bacteria/food fibres.

Haemorrhage control and massive transfusion

Source-specific control

• External: direct pressure, then a tourniquet for exsanguinating limb haemorrhage (proximal, tight, note the time).
• Pelvic fracture: apply a pelvic binder at the level of the greater trochanters to "close the book" on an open-book fracture and tamponade venous bleeding; definitive control by angioembolisation (arterial bleed) or pre-peritoneal packing/external fixation.
• Junctional/torso: operative control. Consider REBOA (resuscitative endovascular balloon occlusion of the aorta) as a temporising measure in selected centres.

Massive transfusion protocol (MTP)

Massive transfusion is classically defined as >10 units of packed red cells in 24 hours, or replacement of one blood volume, or >4 units in 1 hour with ongoing need.

High-yield: Modern damage-control resuscitation uses a balanced ratio of packed red cells : fresh frozen plasma : platelets = 1 : 1 : 1, mimicking whole blood, to pre-empt the dilutional and consumptive coagulopathy of the lethal triad.

Key MTP elements:

• 1:1:1 PRBC:FFP:platelets.
• Tranexamic acid (TXA) — an antifibrinolytic. Per the CRASH-2 trial, give within 3 hours of injury: 1 g IV over 10 min, then 1 g over 8 h. Benefit is lost (and possibly harmful) if given after 3 hours.
• Calcium replacement (citrate in stored blood chelates calcium → hypocalcaemia).
• Warm all fluids/blood; correct acidosis; monitor with viscoelastic testing (TEG/ROTEM) where available to guide component therapy.

Damage-control surgery (DCS)

When physiology cannot tolerate a long definitive operation, do an abbreviated one. The three stages:

1. Stage 1 — Abbreviated laparotomy: control haemorrhage (packing, ligation) and contamination (staple/clamp bowel); leave abdomen open (temporary closure).
2. Stage 2 — ICU resuscitation: rewarm, correct coagulopathy and acidosis, restore physiology over 24–48 h.
3. Stage 3 — Definitive surgery: return to theatre for definitive repair and closure once stable.

High-yield: The trigger for DCS is the deadly triad — hypothermia (<35°C), metabolic acidosis (pH <7.2), and coagulopathy — plus prohibitive operative time. "Stop the bleeding and spillage, fix physiology, repair later."

Special situations & complications

• Pregnant trauma patient: resuscitate the mother first ("best fetal resuscitation is good maternal resuscitation"). After 20 weeks, manual uterine displacement to the left / left lateral tilt relieves aortocaval compression. The mother may maintain normal vitals while the foetus is hypoperfused.
• Paediatric trauma: large physiological reserve → maintain near-normal vitals then crash suddenly; hypotension is a very late, ominous sign. Use weight-based volumes (20 mL/kg crystalloid bolus, 10 mL/kg blood). Hypothermia risk is higher.
• Elderly: beta-blockers mask tachycardia; comorbidities limit reserve. Lower threshold for shock.
• Complications: abdominal compartment syndrome (from over-resuscitation/packing), ARDS, fat embolism (long-bone fracture), MODS, transfusion-related complications (TRALI, citrate toxicity, hyperkalaemia, hypocalcaemia).

Key differentials in the hypotensive trauma patient

Not all shock after trauma is haemorrhagic. Consider:

Type of shock	Clues	Key sign
Haemorrhagic (hypovolaemic)	Most common; bleeding source	Flat neck veins, tachycardia, narrow pulse pressure
Cardiac tamponade (obstructive)	Penetrating chest trauma	Beck's triad: hypotension + muffled heart sounds + distended neck veins; pulsus paradoxus
Tension pneumothorax (obstructive)	Chest trauma, vented patient	Distended neck veins, tracheal deviation, absent breath sounds
Neurogenic	Spinal cord injury (cervical/high thoracic)	Hypotension WITH bradycardia + warm peripheries (loss of sympathetic tone)
Cardiogenic	Blunt cardiac injury, MI	Raised JVP, arrhythmia, pump failure

High-yield: Neurogenic shock = hypotension + bradycardia + warm, well-perfused skin — the bradycardia distinguishes it from haemorrhagic shock (which causes tachycardia). Do not confuse with "spinal shock" (transient flaccid areflexia after cord injury, a neurological not haemodynamic phenomenon).

Recently asked / exam angle

• Earliest sign of shock and the class of haemorrhage matched to vitals/urine output — repeatedly tested; remember tachycardia + narrowed pulse pressure precede hypotension.
• Best/most sensitive FAST window = Morison's pouch (hepatorenal recess).
• Tension pneumothorax is a clinical diagnosis — single best answer for management = needle decompression (then chest tube).
• "GCS ≤ 8 → intubate" and the GCS components.
• MTP ratio 1:1:1 and TXA within 3 hours (CRASH-2) — high-frequency single-liners.
• Neurogenic shock: hypotension + bradycardia — favourite distractor against haemorrhagic shock.
• Beck's triad for cardiac tamponade.
• First peak vs second peak of trimodal death — ATLS targets the second peak.
• NG tube contraindicated in basal skull fracture — choose orogastric.
• Initial crystalloid bolus: 1 L adult / 20 mL/kg paediatric (Ringer's lactate).
• Components/triggers of damage-control surgery and the lethal triad.
• Pelvic binder at greater trochanters; angioembolisation for arterial pelvic bleed.

Rapid revision

1. ATLS sequence: A → B → C → D → E; airway always with C-spine protection; reassess from A if the patient deteriorates.
2. ATLS targets second-peak (golden-hour) deaths — haemorrhage and airway/breathing.
3. GCS ≤ 8 → definitive (cuffed) airway; cricothyroidotomy avoided under age 12.
4. Six lethal chest injuries (ATOM-FC): Airway obstruction, Tension pneumothorax, Open pneumothorax, Massive haemothorax, Flail chest, Cardiac tamponade.
5. Tension pneumothorax is clinical — needle decompression first (2nd ICS MCL or 5th ICS AAL), chest tube definitive.
6. Earliest sign of shock = tachycardia + narrow pulse pressure; hypotension is late (Class III, >30% loss).
7. Two large-bore (14–16 G) IVs; first bolus 1 L Ringer's lactate (20 mL/kg child).
8. FAST answers "free fluid?"; Morison's pouch is the most sensitive window; positive FAST + unstable → laparotomy.
9. CT only in the haemodynamically stable patient; FAST/DPL for the unstable.
10. Massive transfusion = 1:1:1 PRBC:FFP:platelets; TXA within 3 h (CRASH-2); replace calcium, keep warm.
11. Lethal triad = hypothermia + acidosis + coagulopathy → trigger for damage-control surgery (abbreviate, resuscitate, then definitive repair).
12. Neurogenic shock = hypotension + bradycardia + warm skin; Beck's triad = tamponade; pelvic binder at greater trochanters for open-book pelvic fracture.