Surgery — Trauma, NMC MBBS licence examination syllabus (Nepal Medical Council).
Trauma: the primary survey and stopping the bleeding
Trauma care is organised so that the thing that kills soonest is treated first.
An injured patient may have a dozen problems at once, and the temptation is to deal with the most visible one — the deformed limb, the bleeding scalp, the frightened relative. Trauma systems exist because that instinct kills people. The primary survey is a deliberately rigid sequence that forces you to treat problems in the order in which they will cause death.
That is the whole idea, and it explains every apparent oddity in the sequence. An obstructed airway kills in minutes, so it comes before a tension pneumothorax, which kills in slightly longer, which comes before bleeding, which comes before a rising intracranial pressure. The order is not tradition. It is a ranking by speed of death.
🩺 Where this lives: The commonest preventable death in trauma is uncontrolled bleeding, and the commonest reason it is missed is that the blood pressure looked normal. A fit young adult compensates so effectively that the systolic pressure holds until a large volume has been lost — and then falls suddenly. The signs that come earlier are tachycardia, a narrowing pulse pressure, cool peripheries and agitation. A restless trauma patient is shocked or hypoxic until proven otherwise, not difficult.
💡 A note on numbers. This chapter gives no doses or transfusion volumes. Trauma resuscitation is weight-based, protocol-driven and changes with local major-haemorrhage arrangements. Learn the sequence and the reasoning here; take every number from your local protocol.
The primary survey
Two features of the sequence are worth pausing on. First, it is treat as you find — you do not complete an assessment and then act. If you find a tension pneumothorax at B, you decompress it before you look at C. Second, catastrophic external haemorrhage now precedes the airway, because a patient with an open femoral artery will exsanguinate faster than an unmanaged airway will kill them. That is the single most important change in modern trauma teaching.
Chest injuries found at "B"
💡 Exam angle: tension pneumothorax is a clinical diagnosis. The classic error in a question stem is a patient with respiratory distress, absent breath sounds on one side and distended neck veins, where the offered options include "urgent chest X-ray". Requesting the film is the wrong answer — decompression comes first, imaging afterwards. Percussion distinguishes the two great absent-breath-sound diagnoses: hyperresonant means air under tension, dull means a chest full of blood.
Where the blood is
THE LOGIC OF HAEMORRHAGE CONTROL
1. STOP THE BLEEDING. Everything else is supportive.
External → pressure, then tourniquet for a limb
Pelvis → binder at the greater trochanters
Long bone → splint
Cavity → the surgeon or interventional radiology
2. REPLACE WHAT IS LOST WITH WHAT WAS LOST.
Blood, not large volumes of crystalloid. Crystalloid
dilutes clotting factors and does not carry oxygen.
3. AVOID THE LETHAL TRIAD, which makes bleeding worse:
HYPOTHERMIA — keep the patient warm and covered,
warm the fluids
ACIDOSIS — from poor perfusion
COAGULOPATHY— from dilution, consumption and cold
Each worsens the other two. This is why "exposure with
temperature control" is part of the primary survey and
not an afterthought.
4. A PATIENT WHO KEEPS NEEDING FLUID NEEDS AN OPERATION.
Repeated transient responses to fluid mean ongoing
bleeding. Escalate rather than repeating the bolus.
DAMAGE CONTROL SURGERY: in the exsanguinating patient the
first operation is short and aims only to stop bleeding and
contamination. Definitive repair waits until the patient is
warm, perfused and no longer coagulopathic.
Recognising shock before the pressure falls
Head injury
The clinically useful idea in head injury is the split between primary injury, which happened at impact and cannot be undone, and secondary injury, which happens over the following hours and is largely preventable. Hypoxia and hypotension are the two great causes of secondary brain injury — which means that the most effective neuroprotective measure available to you is competent resuscitation of the airway and the circulation.
Clinical reasoning: four presentations
🔍 Case 1 — breathless after a road traffic accident
PresentationA motorcyclist is severely breathless. Trachea deviated, absent breath sounds on the left, hyperresonant to percussion, distended neck veins, systolic pressure falling. The team requests an urgent portable chest X-ray.
TrapConfirming a diagnosis that is already clinical.
ReasoningThese findings are a tension pneumothorax. Air is trapped under pressure, shifting the mediastinum and obstructing venous return, so the patient is dying of obstructed circulation as much as of poor ventilation.
AnswerImmediate decompression, followed by a chest drain. The X-ray is done afterwards, if at all.
🔍 Case 2 — the young patient who looks well
PresentationA 22-year-old fell from a height. Pulse 122, systolic 118, cool hands, capillary refill 4 seconds, agitated and repeatedly trying to sit up. A junior notes the blood pressure is normal.
Key cluesTachycardia, narrow pulse pressure, poor perfusion and agitation.
ReasoningThis patient is compensating. A young person maintains systolic pressure through vasoconstriction until a large volume has gone, and then decompensates abruptly. The agitation is cerebral hypoperfusion, not personality.
AnswerTreat as significant haemorrhage now — find the source across the five sites, activate the major haemorrhage protocol, give blood rather than repeated crystalloid, and keep the patient warm.
🔍 Case 3 — transient response to fluid
PresentationA patient with blunt abdominal trauma improves briefly after fluid, then becomes hypotensive again. FAST shows free fluid. A repeat bolus and a CT are proposed.
Key questionIs this patient stable enough to go to the scanner?
ReasoningA transient responder is still bleeding. Free intraperitoneal fluid in a haemodynamically unstable patient after blunt trauma is an indication for laparotomy, and the CT scanner is a dangerous place for an unstable patient.
AnswerTheatre. Blood, not crystalloid, on the way. CT is for the patient who stabilises and stays stable.
🔍 Case 4 — the head injury that is deteriorating
PresentationAn elderly man on an anticoagulant fell and struck his head. Initially alert, he is now drowsy, GCS has fallen from 15 to 11, and the right pupil is larger than the left. Oxygen saturation 88%, systolic 84.
Two problemsAn expanding intracranial lesion — and hypoxia with hypotension.
ReasoningThe falling conscious level, unequal pupils and anticoagulation demand urgent CT and neurosurgical discussion. But hypoxia and hypotension are actively causing further brain injury while that is arranged.
AnswerCorrect the oxygenation and the blood pressure first — that is the neuroprotection — then urgent imaging, neurosurgical referral and reversal of anticoagulation per protocol. Also look for the cause of the hypotension; it is rarely the head injury itself.
Commonly confused
Confusion
The distinction
Why it matters
Tension pneumothorax vs massive haemothorax
Hyperresonant versus dull to percussion
Both give absent breath sounds; treatment differs.
Tension pneumothorax vs tamponade
Both distend the neck veins; percussion and the mechanism separate them
Decompression versus pericardial drainage.
Imaging vs treating
Tension pneumothorax is diagnosed clinically
Waiting for a film costs the patient minutes they do not have.
Normal BP vs no bleeding
Hypotension is a late sign
Young patients compensate, then crash.
Fluid vs haemorrhage control
Fluid buys time; it does not stop bleeding
Transient responders need theatre, not another bolus.
Crystalloid vs blood
Crystalloid dilutes clotting factors and carries no oxygen
Large volumes worsen the lethal triad.
Primary vs secondary brain injury
One is done; the other is preventable
Resuscitation is the neuroprotection.
Flail chest vs its consequence
The pulmonary contusion causes the hypoxia
Treatment targets oxygenation, not the moving segment.
Rapid revision
MUST-KNOW FACTS
1. The primary survey order ranks problems by SPEED OF DEATH.
2. Catastrophic external haemorrhage is controlled BEFORE the airway.
3. Treat as you find — do not finish assessing before acting.
4. Airway is managed WITH cervical spine control.
5. A patient talking normally has a patent airway — for now.
6. Hoarseness, stridor and an expanding neck haematoma predict airway loss.
7. Tension pneumothorax is a CLINICAL diagnosis — decompress, do not image first.
8. Absent breath sounds + HYPERRESONANT = tension pneumothorax.
9. Absent breath sounds + DULL = massive haemothorax.
10. Open pneumothorax: dressing sealed on THREE sides.
11. Flail chest — the danger is the underlying pulmonary contusion.
12. Tamponade: hypotension, distended neck veins, muffled heart sounds.
13. Five sites of blood loss: floor, chest, abdomen, pelvis, long bones.
14. In trauma, hypotension is BLEEDING until proven otherwise.
15. Tachycardia and a NARROW PULSE PRESSURE come before hypotension.
16. Agitation in a trauma patient means hypoxia or shock.
17. Hypotension is a LATE sign — the young compensate well.
18. Beta-blocked and elderly patients may not mount a tachycardia.
19. Give BLOOD, not large volumes of crystalloid.
20. The lethal triad: HYPOTHERMIA, ACIDOSIS, COAGULOPATHY.
21. Keep the trauma patient WARM — cold patients bleed more.
22. A transient responder is still bleeding — escalate, do not re-bolus.
23. Unstable + free intraperitoneal fluid = laparotomy, not CT.
24. Pelvic binder at the GREATER TROCHANTERS, not the iliac crests.
25. Damage control surgery: stop bleeding and contamination, repair later.
26. Splint long bones early — it reduces bleeding and pain.
27. Check the GLUCOSE at D.
28. GCS = eyes + verbal + motor; minimum 3, never 0; record components.
29. GCS 8 or less — the airway is at risk.
30. Secondary brain injury from HYPOXIA and HYPOTENSION is preventable.
31. Good resuscitation is the best neuroprotection.
32. Deterioration at any point → go back to A and reassess.
💡 Exam angle: trauma questions tend to test sequence rather than knowledge. The stem usually gives you a patient with several problems and asks what to do first — and the answer is almost always the earlier letter of the primary survey, or stopping visible bleeding before anything else. When two options are both correct treatments, choose the one that addresses the problem that kills soonest.
Syllabus points
Why the primary survey is ordered by speed of death
Catastrophic haemorrhage before the airway
Airway with cervical spine control
Life-threatening chest injuries found at B
Tension pneumothorax as a clinical diagnosis
The five sites of major blood loss
Why hypotension is a late sign
The lethal triad and why warmth matters
Transient responders and damage control surgery
Primary versus secondary brain injury
The Glasgow Coma Scale and airway risk
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