Trauma & ATLS Protocols

Advanced Trauma Life Support exists because doctors faced with a badly injured patient reliably do the wrong thing first. They investigate before resuscitating, or they treat the injury that is most visible rather than the one that is most lethal.

The organising tool is a single sentence: treat what kills first, in the order it kills.

The primary survey is not a diagnostic sequence. It is a ranking by how quickly each problem causes death, and every rule in this chapter is a consequence of that ranking.

An obstructed airway kills in minutes, a tension pneumothorax in a few more, and torrential bleeding faster than either. A ruptured spleen may kill in an hour and a head injury over several, which is exactly the order in which they are addressed.

1. The Primary Survey Has Changed

For three decades the sequence was ABCDE. The 11th edition of ATLS, published in 2025, revised it to xABCDE, placing control of exsanguinating haemorrhage before airway management.

The reasoning is simple arithmetic. A patient with an arterial limb bleed can empty their circulation in two or three minutes, faster than a difficult airway will kill them, and a tourniquet takes ten seconds to apply.

Other substantive changes in the 11th edition follow the same logic of prioritising bleeding: greater emphasis on damage control resuscitation with permissive hypotension, earlier use of blood products including whole blood, deliberate restriction of crystalloid, and selective criteria-based spinal motion restriction rather than routine rigid collars.

The survey is interrupted whenever a life-threatening problem is found, treated, and then resumed. It is also repeated whenever the patient deteriorates, because the most common reason for sudden decline is a problem earlier in the sequence than the one being treated.

2. Airway with Cervical Spine Protection

Assessment begins with speech. A patient who answers a question in a normal voice has a patent airway, is ventilating and is perfusing the brain, which clears much of the primary survey in one observation.

Signs of obstruction are stridor, gurgling, snoring, paradoxical chest movement and agitation. Agitation in a trauma patient is hypoxia until proved otherwise, and sedating it is a recognised way to kill someone.

A definitive airway means a cuffed tube in the trachea. Indications include apnoea, inability to protect the airway, a Glasgow Coma Scale of 8 or less, an expanding neck haematoma, major facial or airway burns, and impending obstruction.

The airway is anticipated rather than reacted to, particularly in burns and neck trauma, where oedema converts a manageable airway into an impossible one over a few hours.

Cervical spine protection accompanies airway management, but the 11th edition has moved away from routine rigid collars towards selective, criteria-based motion restriction, and away from them altogether in penetrating neck trauma, where a collar hides expanding haematoma and worsens outcome.

3. Breathing and the Lethal Chest Injuries

Six chest injuries kill in the primary survey and must be found by examination rather than by radiograph.

Tension pneumothorax is a clinical diagnosis and must never wait for imaging. Air enters the pleural space through a one-way valve, the mediastinum shifts, venous return falls and the patient arrests.

The signs are respiratory distress, absent breath sounds and hyperresonance on the affected side, tracheal deviation away from it, distended neck veins and hypotension. Treatment is immediate needle or finger decompression followed by a chest drain.

Open pneumothorax, a sucking chest wound, is covered with a dressing taped on three sides, creating a flutter valve that lets air out but not in. Sealing all four sides converts it into a tension pneumothorax.

Massive haemothorax is more than 1,500 millilitres of blood in the chest, or continued bleeding above 200 millilitres per hour. Breath sounds are absent with dullness rather than hyperresonance, and the patient is treated with blood and a chest drain, with thoracotomy for persistent loss.

Cardiac tamponade gives Beck triad of hypotension, distended neck veins and muffled heart sounds, with pulsus paradoxus. It is confirmed on focused ultrasound and treated by pericardiotomy, with pericardiocentesis as a temporising measure.

Flail chest occurs when three or more consecutive ribs are fractured in two or more places, producing paradoxical movement. The real problem is not the flail segment but the underlying pulmonary contusion, so treatment centres on analgesia, oxygenation and support rather than on the chest wall.

Airway obstruction completes the list, and is managed as in the airway section.

Tension pneumothorax and tamponade both cause obstructive shock with distended neck veins, and the sign that separates them is the chest examination: absent breath sounds with hyperresonance in one, a normal chest in the other.

4. Circulation and Haemorrhagic Shock

Trauma bleeding occurs in five places, and the mnemonic is worth carrying: on the floor and four more, meaning external, chest, abdomen, pelvis and retroperitoneum, and long bones.

The classical shock classification is still taught and examined, though it is increasingly criticised for describing patients who do not exist.

The critical teaching point is that systolic blood pressure falls late. A young patient can lose almost a third of their blood volume with a normal systolic pressure, maintained by vasoconstriction, and the earliest reliable signs are tachycardia and a narrowed pulse pressure.

A narrowed pulse pressure appears in class II because diastolic pressure rises with vasoconstriction while systolic pressure is still maintained, so the gap closes before either number becomes abnormal.

Damage control resuscitation is the current framework, and it reverses several older practices.

Permissive hypotension accepts a systolic pressure of roughly 70 to 90 millimetres of mercury until bleeding is controlled, because raising the pressure dislodges clot and increases blood loss. The exception is traumatic brain injury, where a systolic pressure of at least 90 is maintained to protect cerebral perfusion.

Crystalloid is deliberately restricted and blood products are given early, either as whole blood or as balanced components in a ratio approaching one to one to one of red cells, plasma and platelets. Large-volume crystalloid dilutes clotting factors, worsens acidosis and cools the patient.

Tranexamic acid is given within three hours of injury in significant haemorrhage, and giving it later than three hours is harmful rather than merely useless.

The lethal triad of hypothermia, acidosis and coagulopathy is self-reinforcing: cold blood does not clot, poor perfusion produces acidosis, and acidosis further impairs clotting factor function. Damage control surgery exists to interrupt it by stopping bleeding and contamination quickly and returning later for definitive repair.

5. Disability and Head Injury

The Glasgow Coma Scale scores eye opening out of 4, verbal response out of 5 and motor response out of 6, giving a minimum of 3 and a maximum of 15.

The motor score carries most of the prognostic weight, and a score of 8 or less defines coma and mandates a definitive airway.

Head injury is divided into primary injury, which occurs at the moment of impact and cannot be treated, and secondary injury, which occurs afterwards and can be prevented.

All trauma management of head injury is aimed at secondary injury, whose drivers are hypoxia, hypotension, hypercapnia, hyperthermia and raised intracranial pressure. A single episode of hypotension substantially worsens outcome, which is why the permissive hypotension target is raised in these patients.

Cerebral perfusion pressure equals mean arterial pressure minus intracranial pressure, which is the equation behind every intervention in head injury.

Extradural haematoma is classically arterial from the middle meningeal artery, biconvex on imaging because it is limited by suture lines, and may follow a lucid interval. Subdural haematoma is venous from bridging veins, crescentic and crosses suture lines, and is commoner in the elderly and in alcoholics because brain atrophy stretches those veins.

Cushing response of hypertension, bradycardia and irregular respiration is a late sign of raised intracranial pressure and indicates impending herniation.

6. Abdomen, Pelvis and the Rest

The abdomen is assessed for whether it needs an operation, not for a diagnosis.

Focused assessment with sonography for trauma detects free fluid, and a positive scan in a haemodynamically unstable patient is an indication for laparotomy without further imaging.

A haemodynamically stable patient can have computed tomography, which is far more informative but requires a patient stable enough to be moved and monitored away from the resuscitation room.

Diagnostic peritoneal lavage is now rarely used but retains a place where ultrasound is unavailable.

Solid organ injury in a stable patient is increasingly managed without operation, with monitoring and angioembolisation, whereas instability, peritonitis or evisceration mandate laparotomy.

Pelvic fracture bleeding is venous in the majority of cases, from the presacral venous plexus and from the fracture surfaces, which is why a pelvic binder applied at the level of the greater trochanters works: it reduces the pelvic volume and allows tamponade.

The pelvis is not repeatedly sprung to test for instability, because doing so disrupts clot that has already formed.

A urethral injury is suggested by blood at the meatus, a high-riding prostate and perineal bruising, and urethral catheterisation is deferred until it is excluded.

7. Vascular and Aortic Injury

Limb vascular injury is separated into hard and soft signs, and the distinction determines whether the patient goes to theatre or to a scanner.

Hard signs are pulsatile bleeding, an expanding haematoma, an absent distal pulse, a palpable thrill or audible bruit, and a cold pulseless limb. Any one of them mandates urgent exploration or angiography rather than observation.

Soft signs, such as a history of significant bleeding at the scene, a non-expanding haematoma, an injury adjacent to a major vessel or a neurological deficit, warrant measurement of the injured extremity index and imaging rather than immediate surgery.

Blunt thoracic aortic injury is the injury most often missed on the chest film, and it should be suspected from the mechanism, typically a rapid deceleration such as a high-speed collision or a fall from height.

The classic radiographic clue is a widened mediastinum, with loss of the aortic knuckle contour, depression of the left main bronchus and deviation of a nasogastric tube to the right.

Most patients with a complete transection die at the scene; the survivors have a contained injury at the ligamentum arteriosum, which is where the relatively mobile arch meets the fixed descending aorta. Computed tomography angiography confirms it, and blood pressure and heart rate are actively lowered while repair is arranged.

8. Adjuncts and the Secondary Survey

Adjuncts to the primary survey include monitoring, arterial blood gas, focused ultrasound, and chest and pelvic radiographs.

The secondary survey begins only when the primary survey is complete and the patient is responding to resuscitation. It is a head-to-toe examination with a full history, conventionally taken as allergies, medications, past history, last meal and events.

Every orifice is examined and the back is inspected by log rolling. The commonest missed injuries in trauma are those on the back, in the axillae and perineum, and in the distal limbs.

A tertiary survey is performed at twenty-four hours specifically to find injuries missed during the first two, and it reliably finds some.

9. Special Populations

Children compensate extremely well and then decompensate abruptly. Blood pressure is maintained until a large volume has been lost, so tachycardia and reduced peripheral perfusion are the signals, and hypotension in an injured child is a preterminal sign.

Their larger head to body ratio makes head injury commoner, and their compliant ribs transmit force to the lungs, so pulmonary contusion occurs without rib fractures.

The elderly have reduced physiological reserve, may be on beta blockers that prevent the compensatory tachycardia, and may be anticoagulated, so a normal pulse and a modest mechanism are both falsely reassuring.

In pregnancy the fetus is at risk before the mother shows any sign of shock, because uterine blood flow is sacrificed first to preserve maternal pressure. The mother is resuscitated as the priority, since maternal resuscitation is fetal resuscitation.

After about twenty weeks the gravid uterus compresses the inferior vena cava when the woman lies supine, so she is tilted to the left or the uterus is displaced manually. Placental abruption must be considered after any abdominal trauma.

10. Worked Examples

Example 1. A patient after a road collision has respiratory distress, absent breath sounds on the right with hyperresonance, distended neck veins and a blood pressure of 70 systolic. The resident requests a chest radiograph.

This is tension pneumothorax, and requesting imaging is the error. It is a clinical diagnosis, and the time taken to obtain and review a film is time in which the patient may arrest from obstructed venous return.

Immediate needle or finger decompression is performed, followed by a chest drain. The distended neck veins with hypotension indicate obstructive shock, and the hyperresonant silent chest distinguishes it from tamponade.

Example 2. A 20-year-old man has a pulse of 120, systolic pressure of 118, diastolic of 95 and is anxious after a stab wound to the thigh.

The normal systolic pressure is misleading. Tachycardia with a narrowed pulse pressure indicates class II shock with roughly fifteen to thirty per cent blood volume lost, the diastolic pressure having risen through vasoconstriction while the systolic is still maintained.

Under the current sequence, external exsanguinating haemorrhage is controlled first with direct pressure or a tourniquet, before moving to the airway. Blood products are given rather than large volumes of crystalloid, and tranexamic acid is given within three hours.

Example 3. A pregnant woman at 30 weeks is brought in after a collision, lying supine, with a blood pressure of 90 systolic.

Two things are happening. From about twenty weeks the gravid uterus compresses the inferior vena cava in the supine position, reducing venous return, so she is tilted to the left or the uterus displaced manually before anything else is concluded about her circulation.

Second, uterine perfusion is sacrificed to maintain maternal pressure, so the fetus can be significantly compromised while the mother still looks stable. The mother is resuscitated as the priority, because maternal resuscitation is fetal resuscitation, and placental abruption is actively excluded.

Summary

• Treat what kills first, in the order it kills.
• ATLS 11 changed the primary survey to xABCDE, putting exsanguinating haemorrhage first.
• A patient who speaks normally has a patent airway, is ventilating and is perfusing the brain.
• Agitation in trauma is hypoxia until proved otherwise.
• A Glasgow Coma Scale of 8 or less mandates a definitive airway.
• Airways are anticipated, not reacted to, especially in burns and neck injury.
• Rigid collars are now selective, and are avoided in penetrating neck trauma.
• Tension pneumothorax is a clinical diagnosis and is never imaged first.
• An open pneumothorax is taped on three sides, never four.
• Massive haemothorax is 1,500 millilitres or 200 millilitres per hour continuing.
• Beck triad is hypotension, distended neck veins and muffled heart sounds.
• Distended neck veins with a silent hyperresonant chest means tension, not tamponade.
• In flail chest the pulmonary contusion matters more than the chest wall.
• Bleeding is on the floor and four more: chest, abdomen, pelvis, long bones.
• Systolic pressure falls late; tachycardia and narrowed pulse pressure come first.
• Pulse pressure narrows because diastolic rises with vasoconstriction.
• Permissive hypotension targets 70 to 90 systolic until bleeding is controlled.
• In traumatic brain injury, maintain systolic pressure at 90 or above.
• Crystalloid is restricted; blood products are given early in balanced ratios.
• Tranexamic acid is given within three hours and is harmful after that.
• The lethal triad is hypothermia, acidosis and coagulopathy.
• Damage control surgery interrupts the triad and defers definitive repair.
• Cerebral perfusion pressure is mean arterial pressure minus intracranial pressure.
• Secondary brain injury, not primary, is what treatment can prevent.
• Extradural is arterial and biconvex; subdural is venous and crescentic.
• Cushing response is a late sign of impending herniation.
• Positive focused ultrasound in an unstable patient means laparotomy.
• Pelvic bleeding is mostly venous, so a binder at the trochanters allows tamponade.
• Do not repeatedly spring the pelvis; it disrupts formed clot.
• Defer catheterisation if urethral injury is suspected.
• Hard signs of vascular injury mandate exploration; soft signs warrant imaging.
• Blunt aortic injury follows deceleration and shows a widened mediastinum.
• Survivors of aortic injury have a contained tear at the ligamentum arteriosum.
• Children maintain pressure then crash; hypotension in a child is preterminal.
• Beta blockade and anticoagulation make the elderly falsely reassuring.
• In pregnancy, tilt left after 20 weeks, and resuscitate the mother to save the fetus.