ATLS primary survey and shock: ABCDE, haemorrhage classes and head injury

The primary survey: ABCDE and its adjuncts

ATLS is a system for the first hour, built on one principle: identify and treat the thing that will kill the patient soonest, in that order, and do not move on until it is dealt with. The primary survey is simultaneous in a trauma team and sequential in a single pair of hands, and it is repeated whenever the patient deteriorates. Preparation matters: pre-hospital information, universal precautions, a warmed room and blood available.

A — Airway with restriction of cervical spine motion

A patient who talks has a patent airway for now. Look for obstruction by blood, vomit, teeth or swelling, listen for stridor and gurgling, and anticipate loss of the airway from maxillofacial injury, an expanding neck haematoma, inhalation burn or a falling conscious level. Chin lift or jaw thrust, suction and an oropharyngeal or nasopharyngeal airway (no nasal airway with a suspected base-of-skull fracture) come first. A definitive airway — a cuffed tube in the trachea — is indicated for apnoea, GCS of 8 or less, inability to protect the airway or maintain oxygenation, severe facial burns or inhalation injury, and impending obstruction. When intubation fails, surgical cricothyroidotomy is the rescue airway; in children under about 12, needle cricothyroidotomy with jet insufflation is preferred. The 10th edition says restriction of cervical spinal motion rather than immobilisation: collar, blocks and manual in-line stabilisation until the spine is cleared, with the collar opened for airway work while an assistant holds the head.

B — Breathing and ventilation

Expose the chest. Inspect for wounds, asymmetry, paradoxical movement and distended neck veins; palpate for tenderness, crepitus and tracheal deviation; percuss and auscultate both sides. High-flow oxygen, pulse oximetry and capnography are the monitors. The six life-threatening chest injuries below are found or excluded here.

C — Circulation with haemorrhage control

Level of consciousness, skin colour and temperature, and pulse rate and character diagnose shock in seconds. Compress external bleeding directly; apply a tourniquet for exsanguinating limb haemorrhage that pressure cannot control, and a pelvic binder at the level of the greater trochanters for a suspected pelvic fracture. Insert two large-bore peripheral cannulae in the upper limbs (intraosseous or central access if they fail) and send blood for crossmatch, full blood count, electrolytes, clotting, lactate and an arterial gas, plus a pregnancy test in women of childbearing age. Give 1 L of warmed isotonic crystalloid (20 mL/kg in a child) and move early to blood in any patient who does not respond rapidly.

D — Disability

GCS, pupil size and reactivity, lateralising signs and the level of any spinal cord injury. Hypoglycaemia, alcohol and drugs mimic head injury but are diagnoses of exclusion.

E — Exposure and environment

Undress the patient completely and log-roll to examine the back, then cover and warm: hypothermia worsens coagulopathy and is largely preventable with warmed fluids, forced-air blankets and a warm room.

Adjuncts to the primary survey are done alongside it rather than afterwards: continuous ECG, pulse oximetry, capnography, blood pressure, an arterial blood gas with lactate and base deficit, a urinary catheter (after excluding urethral injury — blood at the meatus, perineal or scrotal haematoma — in which case a retrograde urethrogram comes first), a gastric tube (orogastric if a cribriform plate fracture is possible), chest and pelvic radiographs, and extended FAST. Diagnostic peritoneal lavage survives in the manual but has been replaced in practice by ultrasound and CT.

Life-threatening chest injuries

Haemorrhagic shock

Shock is inadequate tissue perfusion and oxygenation, and in trauma it is haemorrhagic until proved otherwise. Blood is lost ‘on the floor and four more’: externally, into the chest, the abdomen, the pelvis and retroperitoneum, and the long bones — a femoral fracture can hold 1–1.5 L. The body compensates by sympathetic activation (tachycardia, vasoconstriction of skin, gut and kidney, a narrowed pulse pressure) and by drawing fluid in from the interstitium; blood pressure is held until compensation fails, so a normal pressure excludes nothing and a falling pressure is a late sign.

The table's job is to prompt treatment, not to label: a class III patient needs blood now. The response to the initial bolus is the better discriminator. Rapid responders have usually lost under 15% and stopped bleeding; transient responders are still bleeding and need blood and a surgeon; non-responders need immediate haemorrhage control and a search for non-haemorrhagic causes. Children and pregnant women compensate for longer and then collapse abruptly; the elderly and the β-blocked cannot mount a tachycardia and decompensate early.

Tension pneumothorax and cardiac tamponade (obstructive)

Distended neck veins in a shocked trauma patient point here rather than to haemorrhage — unless the patient is also hypovolaemic and the veins are flat. Both are treated by decompression, not by fluid.

Neurogenic shock

Loss of sympathetic tone from a cervical or upper thoracic cord injury: hypotension with bradycardia and warm, dry, vasodilated peripheries. Fluid is given judiciously, then vasopressors; it is a diagnosis made only after haemorrhage has been excluded.

Spinal shock

Not a cardiovascular state at all — the transient flaccid paralysis, areflexia and sensory loss below a cord injury that resolves over days to weeks, with the return of the bulbocavernosus reflex marking its end. Questions confuse the two terms deliberately.

Cardiogenic shock

Blunt cardiac injury, a myocardial infarction that caused the accident, or air embolism. ECG, troponin and echocardiography.

Septic shock

A late cause after a missed hollow-viscus injury or contaminated wound, not a cause of shock on arrival after acute trauma.

Damage-control resuscitation

The modern approach, embedded in the 10th edition, aims to stop the bleeding and to avoid the lethal triad of hypothermia, acidosis and coagulopathy, with hypocalcaemia from citrated blood increasingly cited as a fourth corner. Crystalloid is limited to the initial litre because it dilutes clotting factors, cools the patient and raises the pressure that dislodges the clot; blood products are started early, and massive transfusion is given in a balanced ratio of plasma, platelets and red cells approaching 1:1:1. Tranexamic acid is given to bleeding trauma patients within three hours of injury — 1 g intravenously over 10 minutes followed by 1 g over eight hours, the CRASH-2 regimen — because it reduced mortality when given early and appeared harmful when given later. Calcium is replaced, the patient is kept warm, and viscoelastic testing (TEG or ROTEM) guides further plasma, platelets, fibrinogen and cryoprecipitate where it is available.

FAST and CT

Focused Assessment with Sonography in Trauma looks for free fluid in four windows — pericardial, hepatorenal (Morison's pouch), splenorenal and pelvic (the pouch of Douglas or rectovesical pouch) — and the extended examination adds anterior chest views for pneumothorax and haemothorax. It is fast, repeatable and done in the resuscitation bay, but it is operator dependent, cannot grade solid-organ injury, misses retroperitoneal and hollow-viscus injury, and a negative scan does not exclude bleeding. The decision rule is simple: an unstable patient with a positive FAST goes to theatre for laparotomy; an unstable patient with a negative FAST has the chest, pelvis and long bones examined again and the abdomen reconsidered; a stable patient goes to CT. Contrast-enhanced CT is the definitive investigation for the stable patient — it grades liver, spleen and kidney injuries, shows the active extravasation that interventional radiology can embolise, and examines the retroperitoneum, spine and pelvis — and whole-body CT is standard for major blunt trauma. The scanner is no place for a non-responder.

Glasgow Coma Scale and head injury

Head injury management is about preventing secondary brain injury. The primary injury is done at impact; what follows — hypoxia, hypotension, hypercapnia or hypocapnia, hyperthermia, seizures, raised intracranial pressure and an expanding haematoma — is preventable. Cerebral perfusion pressure is mean arterial pressure minus intracranial pressure, and the Monro–Kellie doctrine explains why a mass is tolerated until the buffering capacity of venous blood and CSF is exhausted and pressure then climbs steeply. Cushing's response (hypertension, bradycardia, irregular breathing) and a unilateral fixed dilated pupil (uncal herniation compressing the oculomotor nerve) are signs of impending herniation: intubate and ventilate to normocapnia, nurse head-up at 30°, maintain blood pressure, give hypertonic saline or mannitol as a bridge, and get to the neurosurgeon or the scanner. The classic lucid interval belongs to the extradural haematoma from the middle meningeal artery beneath a temporal fracture; the subdural haematoma from torn bridging veins is commoner, especially in the elderly and anticoagulated, and carries a worse prognosis because of the underlying brain injury.

NICE NG232 (Head injury: assessment and early management, 2023) sets the CT criteria in adults. Key criteria for a CT head within one hour include: GCS below 13 on initial assessment, GCS below 15 two hours after the injury, a suspected open or depressed skull fracture, any sign of a basal skull fracture (haemotympanum, periorbital bruising, cerebrospinal fluid leak from ear or nose, Battle's sign), a post-traumatic seizure, a focal neurological deficit, and more than one episode of vomiting. A CT within eight hours (or within one hour if the patient presents more than eight hours after injury) is indicated for patients who have had loss of consciousness or amnesia with any of: age 65 or over, a bleeding or clotting disorder, a dangerous mechanism (a pedestrian or cyclist struck by a vehicle, an occupant ejected, a fall of more than 1 m or five stairs), or more than 30 minutes of retrograde amnesia; and is considered for patients on anticoagulant or antiplatelet treatment (other than aspirin alone) even without other indications. Children have a separate algorithm. These are the headlines; consult the guideline for the full list.

Secondary and tertiary surveys

The secondary survey begins only when the primary survey is complete, resuscitation is under way and vital signs are improving. It is a head-to-toe examination — scalp and skull, face and eyes, neck, chest, abdomen and pelvis, perineum (rectal and vaginal examination when indicated rather than by routine), the limbs including distal pulses and a check for compartment syndrome, and a log-rolled examination of the back and spine — with a full neurological examination and an AMPLE history: allergies, medications, past illnesses and pregnancy, last meal, and the events and environment of the injury, because mechanism predicts injury (a frontal impact predicts posterior hip dislocation and aortic injury; a fall from height, calcaneal and lumbar fractures). Limb radiographs and any CT the primary survey did not already demand are ordered here. A patient who needs transfer to a major trauma centre is transferred as soon as the need is recognised; the secondary survey does not delay it.

The tertiary survey is a repeat head-to-toe examination and a review of every image and result within 24 hours of admission, ideally by a fresh pair of eyes and once the patient is awake enough to complain. Its target is the missed injury — small fractures of the hands and feet, ligamentous injuries, a second rib fracture, a scaphoid — which occur in a meaningful proportion of major trauma patients, particularly those who were intubated, intoxicated or distracted by a more painful injury on arrival.