Haemodynamics: septic shock: practice question

A Pathology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Pathology · Haemodynamics: septic shock

Sample item

A 55-year-old man with pyelonephritis has blood pressure 80/50 mmHg, warm flushed skin, bounding pulses, raised cardiac output and a serum lactate of 5 mmol/L despite adequate fluid resuscitation. Which pathogenetic mechanism best explains his haemodynamic state?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Cytokine and nitric oxide mediated systemic vasodilation with maldistribution of flow

In septic shock, endotoxin and other microbial products stimulate TNF, IL-1 and IL-6 release and induce nitric oxide synthase, causing widespread arteriolar vasodilation and increased vascular permeability. Cardiac output is often high early on, so the skin is warm, yet tissue perfusion is poor, which explains the lactate. Endothelial injury also predisposes to DIC.

Option by option

  • A. Obstruction of ventricular filling by a pericardial effusion

    Tamponade is obstructive shock with raised venous pressure and low output, not warm skin with bounding pulses.

  • B. Primary pump failure from extensive myocardial necrosis

    Cardiogenic shock gives cold, clammy skin and low cardiac output, the opposite of this picture.

  • C. Loss of circulating volume through haemorrhage into the retroperitoneum

    Hypovolaemic shock is cold with a low output and responds to fluid, which has already been given.

  • D. Cytokine and nitric oxide mediated systemic vasodilation with maldistribution of flow (correct)

    Correct. Vasodilation with shunting and leaky capillaries produces warm, hypotensive shock with high output.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Pathology question

What is the answer to this Pathology question?

The best answer is D, Cytokine and nitric oxide mediated systemic vasodilation with maldistribution of flow. In septic shock, endotoxin and other microbial products stimulate TNF, IL-1 and IL-6 release and induce nitric oxide synthase, causing widespread arteriolar vasodilation and increased vascular permeability.

Why is "Obstruction of ventricular filling by a pericardial effusion" not the answer?

Tamponade is obstructive shock with raised venous pressure and low output, not warm skin with bounding pulses.

Why is "Primary pump failure from extensive myocardial necrosis" not the answer?

Cardiogenic shock gives cold, clammy skin and low cardiac output, the opposite of this picture.

Why is "Loss of circulating volume through haemorrhage into the retroperitone…" not the answer?

Hypovolaemic shock is cold with a low output and responds to fluid, which has already been given.

What concept does this question test?

It tests Haemodynamics: septic shock in Pathology. Cardiac output is often high early on, so the skin is warm, yet tissue perfusion is poor, which explains the lactate. Endothelial injury also predisposes to DIC.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Haemodynamics: septic shock?

Learn each disease as a bundle: cause, key histology, markers, and the clinical hallmark. Then use the flashcards and the other Pathology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.