Can a patient be shocked with a normal blood pressure?

Yes. The Resuscitation Council UK states that even in shock the blood pressure may be normal, because compensatory mechanisms increase peripheral resistance in response to reduced cardiac output. Cool peripheries, a prolonged capillary refill, a narrowed pulse pressure and oliguria all show shock before the systolic falls.

What does the pulse pressure tell you in shock?

A narrowed pulse pressure, where the difference between systolic and diastolic is less than the normal 35 to 45 mmHg, suggests arterial vasoconstriction and therefore cardiogenic shock or hypovolaemia. A low diastolic pressure suggests arterial vasodilation, which points to distributive causes such as anaphylaxis or sepsis.

Is the fluid bolus 500 ml or 250 ml?

It depends on which guideline applies. The Resuscitation Council UK ABCDE guidance gives 500 ml of crystalloid over less than 15 minutes to a hypotensive adult, and 250 ml in known cardiac failure or trauma. NICE NG253 for suspected sepsis gives 250 ml boluses up to 1,000 ml in total before senior advice is sought.

How is capillary refill time measured properly?

Apply cutaneous pressure for 5 seconds on a fingertip held at heart level or just above, with enough pressure to cause blanching, then time the return to the surrounding colour. The normal value is under 2 seconds, and cold surroundings, poor lighting and old age can all prolong it.

Which cannula should you use in shock?

The Resuscitation Council UK recommends one or more large 14 or 16 gauge cannulae, chosen short and wide bore because that gives the highest flow. Take haematology, biochemistry, coagulation, microbiology and cross-match samples from the cannula before starting fluid.

When should fluid be stopped in shock?

When signs of cardiac failure appear, which the guidance lists as dyspnoea, a rising heart rate, a raised jugular venous pulse, a third heart sound and pulmonary crackles. At that point decrease the infusion rate or stop it, and seek alternative means of improving tissue perfusion such as inotropes or vasopressors.

Shock, Recognition and Management by Type — CT1 Anaesthetics Interview Clinical Judgement Answer

Shock is inadequate tissue perfusion, and it is recognised at the bedside before any number confirms it. According to the Resuscitation Council UK ABCDE guidance, updated in July 2024, hypovolaemia should be considered the primary cause of shock in almost all medical and surgical emergencies until proven otherwise. At the CT1 anaesthetics interview the marks are for the bedside findings, for naming which type of shock you think this is, and for saying what would change your mind.

Key takeaways

Blood pressure can be normal in shock, because compensatory vasoconstriction raises peripheral resistance as cardiac output falls (Resuscitation Council UK)
A low diastolic pressure suggests vasodilation, as in anaphylaxis or sepsis; a narrowed pulse pressure, normally 35 to 45 mmHg, suggests vasoconstriction from cardiogenic shock or hypovolaemia
Capillary refill is measured with 5 seconds of pressure on a fingertip held at or just above heart level, and is normally under 2 seconds
The Resuscitation Council UK fluid challenge is 500 ml of crystalloid over less than 15 minutes if hypotensive, or 250 ml in known cardiac failure or trauma, reassessing every 5 minutes
In suspected sepsis the volume is different: NICE NG253 gives 250 ml boluses to a maximum of 1,000 ml before senior advice
Oliguria below 0.5 ml/kg/hour and a reduced conscious level are both signs of poor cardiac output, not incidental findings

How do you recognise shock at the bedside?

Shock is recognised from the hands, the pulse and the conscious level before the blood pressure. The Resuscitation Council UK asks you to look at the colour of the hands and digits and feel whether they are cool or warm.

Capillary refill time: 5 seconds of cutaneous pressure on a fingertip at or just above heart level, normally under 2 seconds, prolonged by cold surroundings, poor lighting and age
Veins: underfilled or collapsed when hypovolaemia is present
Pulses: barely palpable central pulses suggest a poor cardiac output, while a bounding pulse may indicate sepsis
Blood pressure: normal does not exclude shock, and the diastolic and pulse pressure carry the information
Urine output: below 0.5 ml/kg/hour in a catheterised patient is a sign of poor perfusion
Haemorrhage: look for external bleeding from wounds and drains, and for concealed thoracic, intra-abdominal, retroperitoneal or gut losses

However, the guidance is blunt about one thing: empty drains do not exclude significant intra-thoracic, intra-abdominal or pelvic blood loss. In a surgical patient, haemorrhage is excluded actively, not assumed away.

Which type of shock is it?

Shock is conventionally grouped into hypovolaemic, distributive, cardiogenic and obstructive, and the bedside findings usually tell you which group you are in. The Resuscitation Council UK gives two specific discriminators worth quoting.

A low diastolic blood pressure suggests arterial vasodilation, as in anaphylaxis or sepsis, which is distributive shock. A narrowed pulse pressure suggests arterial vasoconstriction, which points to cardiogenic shock or hypovolaemia.

The guidance also names the immediately life-threatening conditions to look for while you assess: cardiac tamponade, massive or continuing haemorrhage, and septicaemic shock. Tension pneumothorax belongs to breathing and should already have been treated.

What do you do in the first ten minutes?

In the first ten minutes of a shock scenario you follow ABCDE, treat each life-threatening problem as you find it, get access and give fluid, while help is already coming. The Resuscitation Council UK calls this treating before moving on.

Attach pulse oximetry, ECG and non-invasive blood pressure as soon as possible in any critically ill patient
Insert one or more large cannulae, 14 or 16 gauge, short and wide bore because they give the highest flow
Take bloods for haematology, biochemistry, coagulation, microbiology and cross-matching from the cannula before infusing fluid
Give oxygen: a reservoir mask at 15 litres per minute in critical illness, titrated later to the target range
Record a 12-lead ECG early if there is primary chest pain and a suspected acute coronary syndrome
Measure a bedside glucose, because hypoglycaemia is a treatable cause of the reduced conscious level that shock produces

The guidance says to wait a short while before reassessing, because treatments take a few minutes to work. Reassessing instantly and escalating on no data is a common pressure error.

How much fluid, and does the answer change in sepsis?

For undifferentiated shock the Resuscitation Council UK gives a bolus of 500 ml of crystalloid, such as Hartmann's solution or 0.9% sodium chloride, over less than 15 minutes if the patient is hypotensive.

Smaller volumes, for example 250 ml, are used in known cardiac failure or trauma, with closer monitoring and auscultation for crackles after each bolus. If there is no improvement, repeat the challenge and seek expert help if repeated boluses do nothing.

Yes, the answer changes in sepsis. NICE NG253, published in November 2025, gives an initial 250 ml bolus ideally over 10 to 15 minutes, further 250 ml boluses up to 1,000 ml in total, then a senior clinical decision maker.

What are the numbers you reassess against?

In a shock scenario you reassess the heart rate and blood pressure every 5 minutes, aiming for the patient's own normal blood pressure or, if that is unknown, a systolic above 100 mmHg. Those figures are the Resuscitation Council UK's.

Alongside them, track the capillary refill, the conscious level and the urine output, which is the perfusion measure that does not lie. A rising lactate on a gas tells you the perfusion deficit is not corrected.

If signs of cardiac failure appear, which the guidance lists as dyspnoea, a rising heart rate, a raised jugular venous pulse, a third heart sound and pulmonary crackles, slow or stop the fluid and look for another way to improve perfusion.

How is each type of shock treated differently?

Each type of shock needs the same ABCDE and a different definitive treatment, and saying both is what scores. The Resuscitation Council UK states that treatment of cardiovascular collapse depends on the cause, directed at fluid replacement, haemorrhage control and restoring tissue perfusion.

Hypovolaemic and haemorrhagic: stop the bleeding, replace volume, involve surgery or interventional radiology, and give blood rather than crystalloid once haemorrhage is the answer
Distributive from sepsis: NICE NG253 antibiotics within 1 hour at high risk, 250 ml boluses to 1,000 ml, source control and early critical care
Distributive from anaphylaxis: intramuscular adrenaline 500 micrograms and a rapid 500 to 1,000 ml bolus, per Resuscitation Council UK 2021
Cardiogenic: an early 12-lead ECG, aspirin 300 mg crushed or chewed and sublingual glyceryl trinitrate for suspected acute coronary syndrome, oxygen only if the saturation is below 94% on air, and morphine titrated to avoid sedation
Obstructive: decompress a tension pneumothorax at the breathing step and get urgent help for suspected tamponade

In practice the anaesthetic contribution to shock is access, airway and transfer. Say which of those you would personally do, because that is what the referrer is calling for.

When do vasopressors and inotropes start?

Vasopressors and inotropes start when fluid has not worked, or when fluid is the wrong answer. The Resuscitation Council UK says to seek alternative means of improving tissue perfusion, such as inotropes or vasopressors, once signs of cardiac failure appear.

In sepsis specifically, NICE NG253 asks you to discuss with the critical care team, or the senior clinical decision maker if critical care is not available, whether to give vasopressors and whether to start them peripherally.

If they are started peripherally, the guideline asks for local policy on choice, dose, concentration and monitoring, a visible line and cannula, and watchfulness for extravasation. That is a level of detail that separates candidates.

When do you call for help, and who?

In a shock scenario you call at the moment you recognise shock, not when fluid has failed. The Resuscitation Council UK lists recognising when you need extra help and calling early among the underlying principles of the approach.

Who you call follows the type. Surgery or interventional radiology for haemorrhage and for a drainable source, cardiology for cardiogenic shock, and critical care for anyone needing vasopressors or a level 3 bed.

Use a structured handover. The guidance names SBAR and RSVP, and a shock referral that opens with the blood pressure trend and the volume already given is one the registrar can act on immediately.

What do the assessors score besides the algorithm?

Beyond the algorithm, the assessors in a shock scenario score whether you use the whole team. The Resuscitation Council UK principle is to use all team members so that assessment, monitoring and access happen simultaneously rather than in sequence.

Reflective practice is a named domain, and a good example is a shocked patient you treated as hypovolaemic who turned out to be bleeding or septic, and the reassessment habit you built afterwards.

Working under pressure is scored in how you hold a working diagnosis loosely. Saying what would change your mind, for instance a lactate that keeps rising after 1,000 ml, is stronger than sounding certain.

Which mistakes cost marks in a shock scenario?

The shock mistakes at interview come from treating a number rather than a patient, and from mixing up which guideline a volume belongs to.

Waiting for hypotension: compensation keeps the blood pressure normal while the cardiac output falls
Giving 500 ml boluses to a septic patient, when NICE NG253 gives 250 ml to a maximum of 1,000 ml
Giving a full 500 ml to a patient with known cardiac failure or trauma, where the Resuscitation Council UK uses 250 ml with closer monitoring
Treating haemorrhagic shock with crystalloid alone instead of stopping the bleeding and giving blood
Forgetting that empty drains do not exclude concealed haemorrhage
Never naming a reassessment interval, when the guidance asks for heart rate and blood pressure every 5 minutes

How this comes up at the CT1 anaesthetics interview

Shock reaches the clinical judgement station as a referral you cannot fully diagnose: a hypotensive post-operative patient, or a cold and clammy patient on a medical ward. The station is 15 minutes after five minutes of reading, marked out of 50.

Clinical judgement and decision making is scored on the type, the volume and the reassessment. Reflective practice is scored on the diagnosis you once anchored on, and working under pressure on whether you keep the team working in parallel.

The follow-up usually removes an option: no cross-matched blood, no critical care bed, or a patient who deteriorates while you are on the phone. anaestheticinterview's bank of 340 questions carries AI-marked spoken practice for exactly that kind of pressure.

Shock: Recognition and Management by Type