The nurse recognizes that the "normal" hourly urine output for a healthy adult is approximately:

Appeared in: BTSC 3 August 2025

Explanation

The standard accepted range for normal hourly urine output in a healthy adult is approximately 30–50 mL.
This value is derived from the physiological standard of 0.5–1 mL of urine per kilogram of body weight per hour.
Maintaining this rate of output is a key indicator of adequate hydration, sufficient blood volume, and proper kidney perfusion.
A urine output within this range suggests the body is effectively filtering waste and maintaining fluid and electrolyte balance.

Option A: An hourly urine output of 10–20 mL is considered oliguria (abnormally low urine production).
Option C: While a healthy adult can produce 60–80 mL of urine per hour, especially with high fluid intake, this is higher than the standard baseline average used for clinical assessment.
Option D: An output of 100–120 mL/hr is considered high and, if sustained, is termed polyuria (excessive urination).

Clinical Relevance

Nursing practice connection: Knowing Normal hourly urine output in adults helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Monitoring urine output is a fundamental nursing skill used to assess a patient's fluid status, renal perfusion, and overall response to treatment.
A urine output of less than 30 mL/hr for two or more consecutive hours is a critical finding that must be reported to the healthcare provider, as it may signal the onset of acute kidney injury (AKI).
Accurate intake and output (I&O) charting is essential in postoperative patients, critically ill patients, and those with cardiac or renal conditions.

How to Approach the Question

Identify the keywords in the question: 'normal', 'hourly urine output', and 'healthy adult'.
Recognize this as a factual recall question that tests knowledge of basic physiological parameters.
Recall the standard clinical value for normal hourly urine output, which is 0.5–1 mL/kg/hr.
Mentally calculate this for an average adult weight (e.g., 60 kg person = 30-60 mL/hr).
Compare this calculated range to the given options.
Select the option (30–50 mL/hr) that best represents this standard baseline, eliminating the options that are too low (oliguria) or too high (polyuria).

Concept Tested & Keywords

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E6 Nursing Vital Signs p. 114-116

E6 Nursing Fundamentals Potter Perry 12e Part 5 p. 244-246

Practise the full BTSC 3 August 2025

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