Urine output: practice question

A Anaesthesia 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.

Try it

Anaesthesia · Urine output

Sample item

A 70 kg adult is in the recovery unit after major abdominal surgery with a urinary catheter in place. The nurse asks which hourly urine volume is generally accepted as showing adequate renal perfusion. Which is it?

AAbout 35 mL per hour (0.5 mL/kg/h)BAbout 210 mL per hour (3 mL/kg/h)CAbout 7 mL per hour (0.1 mL/kg/h)DAbout 140 mL per hour (2 mL/kg/h)

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

The answer and the reasoning

A. About 35 mL per hour (0.5 mL/kg/h)

A urine output of at least 0.5 mL/kg/h in adults is taken as a simple bedside indicator that renal perfusion and intravascular volume are adequate. A persistent fall below this suggests hypovolaemia, low cardiac output or renal injury and should prompt a search for the cause.

Option by option

A. About 35 mL per hour (0.5 mL/kg/h) (correct)
Correct. 0.5 mL/kg/h is the usual adult minimum and equals about 35 mL for 70 kg.
B. About 210 mL per hour (3 mL/kg/h)
3 mL/kg/h is a diuresis, not the minimum acceptable output.
C. About 7 mL per hour (0.1 mL/kg/h)
0.1 mL/kg/h is far below the threshold and indicates oliguria.
D. About 140 mL per hour (2 mL/kg/h)
2 mL/kg/h is higher than required and is not a minimum target in adults.

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.

Questions about this Anaesthesia question

What is the answer to this Anaesthesia question?

The best answer is A, About 35 mL per hour (0.5 mL/kg/h). A urine output of at least 0.

Why is "About 210 mL per hour (3 mL/kg/h)" not the answer?

3 mL/kg/h is a diuresis, not the minimum acceptable output.

Why is "About 7 mL per hour (0.1 mL/kg/h)" not the answer?

0.1 mL/kg/h is far below the threshold and indicates oliguria.

Why is "About 140 mL per hour (2 mL/kg/h)" not the answer?

2 mL/kg/h is higher than required and is not a minimum target in adults.

What concept does this question test?

It tests Urine output in Anaesthesia. 5 mL/kg/h in adults is taken as a simple bedside indicator that renal perfusion and intravascular volume are adequate. A persistent fall below this suggests hypovolaemia, low cardiac output or renal injury and should prompt a search for the cause.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Urine output?

Make a table of each agent, its key advantage and its main side effect. Then use the flashcards and the other Anaesthesia 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.