Shock is inadequate tissue perfusion, and in a surgical patient the cause is bleeding until proven otherwise. The CST answer is to recognise it early from the physiology rather than the blood pressure, to activate the major haemorrhage protocol and replace blood with blood at a 1:1 plasma to red cell ratio as NICE NG39 directs, to give tranexamic acid within 3 hours, and to get the patient to a surgeon who can stop the bleeding.

Key takeaways

  • Shock is a failure of perfusion, not a number. Tachycardia, cold peripheries, a capillary refill over 2 seconds, falling urine output and a rising lactate come before the systolic pressure falls.
  • According to NICE NG39, in hospital do not use crystalloids for patients with active bleeding; replace volume with 1 unit of plasma to 1 unit of red blood cells.
  • NG39 says give intravenous tranexamic acid as soon as possible in major trauma with active or suspected bleeding, and do not give it more than 3 hours after injury unless there is evidence of hyperfibrinolysis.
  • NG39 says use damage control surgery in patients with haemodynamic instability who are not responding to volume resuscitation.
  • For the non-bleeding shocked patient, NICE CG174 gives a 500 ml crystalloid bolus over less than 15 minutes, triggered by a systolic under 100 mmHg, a heart rate over 90, a capillary refill over 2 seconds, a respiratory rate over 20 or a NEWS of 5 or more.
  • The four shock types the panel expects are hypovolaemic, distributive (septic, anaphylactic, neurogenic), cardiogenic and obstructive, and the treatment differs for each.

How do I recognise shock and haemorrhage on a surgical ward?

Shock is recognised from the signs of hypoperfusion: tachycardia, cool or mottled peripheries, prolonged capillary refill, tachypnoea, reduced urine output, confusion or agitation, and a raised lactate on the gas. A normal blood pressure does not exclude it, because young patients compensate until they collapse.

Haemorrhage in a surgical patient may be visible in a drain or a dressing, or hidden in the abdomen, the pelvis, the retroperitoneum or the thigh. The panel expects you to say where a litre can hide.

What are the four types of shock?

  • Hypovolaemic: haemorrhage, or fluid loss from vomiting, a high-output stoma, a fistula or third-spacing
  • Distributive: septic shock, anaphylaxis, or neurogenic shock after spinal injury or a high block
  • Cardiogenic: a peri-operative myocardial infarction, an arrhythmia or acute heart failure
  • Obstructive: massive pulmonary embolism, tension pneumothorax or cardiac tamponade

In practice the history sorts them. A patient two hours after an aortic graft with a falling haemoglobin is bleeding; a patient on day five after a colectomy with a fever and a lactate of 4 is septic.

What is the immediate management from A to E?

Immediate management is ABCDE with circulation as the focus: oxygen, two wide-bore cannulae, bloods including a crossmatch and a blood gas, and direct pressure on any external bleeding. NG39 says use a tourniquet on a limb if direct pressure has failed to control life-threatening haemorrhage, and a pelvic binder for a suspected pelvic fracture.

  • Airway and breathing: high-flow oxygen through a reservoir mask, then a target range once stable
  • Circulation: access, group and save or crossmatch, full blood count, clotting, fibrinogen, urea and electrolytes, and a venous gas for lactate and haemoglobin
  • Circulation: if bleeding, activate the major haemorrhage protocol and give blood components rather than crystalloid
  • Circulation: if not bleeding and the CG174 indicators are present, a 500 ml crystalloid bolus over less than 15 minutes, then reassess
  • Disability and exposure: conscious level, glucose, temperature, and a search for the source including the wound, drains, abdomen and thighs

According to NICE NG39, in pre-hospital settings volume is titrated to a palpable central pulse, and crystalloid is used only if blood components are unavailable. On a ward, that principle becomes: do not chase a normal blood pressure with clear fluid while the patient is still bleeding.

Which investigations change the decision?

The decisive investigations are the blood gas, for lactate, haemoglobin and base deficit, and the clotting screen with fibrinogen, because they tell you how far behind you are. A haemoglobin on the gas can be misleadingly normal in the first hour of a bleed, so the trend matters more than the value.

Imaging follows stability. A stable patient with suspected intra-abdominal bleeding has a CT with contrast; an unstable patient who is not responding goes to theatre, and NG39 is explicit that damage control surgery is the answer for instability that does not respond to volume.

What is the definitive management of haemorrhagic shock?

Definitive management is stopping the bleeding, and everything before that is holding the patient together long enough to get there. Blood components, tranexamic acid, warming and calcium keep the clotting working; the surgeon or interventional radiologist ends the haemorrhage.

What does the major haemorrhage protocol deliver?

The major haemorrhage protocol is the hospital's pre-agreed route to universal group O red cells and thawed plasma without waiting for a full crossmatch. NG39 sets the adult ratio at 1 unit of plasma to 1 unit of red blood cells. The British Society for Haematology's 2022 guideline gives the laboratory targets for haemoglobin, fibrinogen and platelets that your transfusion laboratory will apply; check the local protocol for the numbers rather than quoting them from memory.

Tranexamic acid is given intravenously as soon as possible. NG39 says not to give it more than 3 hours after injury unless there is evidence of hyperfibrinolysis, because the benefit is front-loaded.

What are damage control principles?

Damage control surgery is an abbreviated operation that controls bleeding and contamination, packs the abdomen and leaves it open, then returns the patient to critical care to be warmed, transfused and corrected before definitive surgery. The lethal triad it interrupts is hypothermia, acidosis and coagulopathy.

When do I escalate, and who do I call?

Escalate the moment you suspect major haemorrhage: the surgical registrar and consultant, the anaesthetist, the blood bank through the major haemorrhage call, and critical care. This is one of the few ward emergencies where the consultant is called first, not last.

  • Any suspected post-operative bleed: the operating registrar and consultant, now
  • A patient not responding to volume: theatre, and NG39's damage control principle
  • A stable patient with a contained bleed: interventional radiology, via the consultant
  • Massive transfusion in progress: haematology or the transfusion laboratory for component advice

How do non-haemorrhagic causes change the plan?

Non-haemorrhagic shock changes the fluid and the target. Septic shock follows NICE NG253 with 250 ml boluses to 1,000 ml and vasopressors to a mean arterial pressure of 65 mmHg under the Surviving Sepsis 2026 guideline; anaphylaxis needs intramuscular adrenaline; a massive pulmonary embolism with haemodynamic instability needs unfractionated heparin and consideration of thrombolysis under NICE NG158.

However clear the surgical story, a peri-operative myocardial infarction can present as shock. An ECG and a troponin belong in every shocked patient over 50.

What is the interviewer listening for?

  • Shock defined as a perfusion problem, with the compensated patient recognised before the blood pressure falls
  • Blood replaced with blood: NG39's 1:1 plasma to red cell ratio and no crystalloid for active bleeding in hospital
  • Tranexamic acid as soon as possible and the 3-hour limit
  • The major haemorrhage call made early, and the consultant called first
  • Damage control principles stated as the reason an unstable patient goes to theatre rather than the scanner

What are the common mistakes?

  • Litres of crystalloid to normalise a blood pressure in a patient who is still bleeding
  • Waiting for a haemoglobin to fall before believing the tachycardia
  • Taking an unstable patient to CT
  • Forgetting warming and calcium, so that the transfused blood does not clot
  • Failing to say the consultant's name in the escalation

How this comes up at the CST interview

The CST management and clinical station marks a structured approach, knowledge, prioritisation and communication. A bleeding patient tests the order of your ABCDE, whether you know NG39's rules, whether you call the right people in the right order, and whether you can say it in one calm minute.

coresurgeryinterview builds its 299-question bank around the portfolio, management and clinical stations, and its post-operative bleeding scenario is scored on exactly this sequence: recognise, resuscitate with blood, tranexamic acid, escalate, theatre.