Oliguria means?

Appeared in: UPPSC-2021

Explanation

Oliguria is clinically defined as a urine output of less than 400 mL over a 24-hour period in adults.
This volume is significant because it indicates that the kidneys are not adequately filtering waste products from the blood.
It is a critical sign of deteriorating renal function, which can be caused by dehydration, shock, or acute kidney injury (AKI).
The threshold of 400 mL is the minimum volume needed to excrete the body's daily load of metabolic wastes.

Option A: This describes nocturia, which is the need to wake and pass urine at night, often more than during the day.
Option B: This is the definition of anuria, which is a more severe condition representing a near-complete cessation of urine production.
Option C: This option uses an incorrect volume and an unusually short time frame (2 hours) that does not align with any standard clinical definition for oliguria or anuria.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Definition of Oliguria as background academic context rather than a clinical decision trigger.
Accurate measurement and documentation of urine output are fundamental nursing responsibilities, as changes are often the first sign of a patient's condition worsening, especially in critically ill patients.
Oliguria is a major criterion in the diagnosis and staging of Acute Kidney Injury (AKI). Prompt identification and intervention can prevent progression to more severe kidney damage.
What if? If the patient were a child, the definition of oliguria would change. For children, it is defined as urine output less than 1 mL/kg/hr, and for infants, less than 0.5 mL/kg/hr. The absolute volume is less important than the rate relative to body weight.

How to Approach the Question

This is a factual recall question that tests your knowledge of a specific medical term.
First, identify the keyword in the question stem, which is 'Oliguria'.
Recall the standard clinical definition of this term, focusing on both the volume of urine and the time frame.
Systematically evaluate each option against the recalled definition.
Eliminate options that define other conditions (like nocturia or anuria) or use incorrect values and time frames.
Select the option that precisely matches the definition of oliguria: less than 400 mL in 24 hours.

Concept Tested & Keywords

Q0U3VWX0NUOUZ3reP5Oiyj

E6 Medicine Davidson Principles Practice 24e p. 411-413

E6 Medicine Harrison 22e Part 2 p. 284-286

E6 Nursing Vital Signs p. 114-116

Practise the full UPPSC-2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.