What does a positive leukocyte esterase test indicate?

Appeared in: UPUMS Nsg officer-2023

Explanation

A positive leukocyte esterase test is a direct indicator of pyuria.
Leukocyte esterase is an enzyme produced by neutrophils, a type of white blood cell (WBC).
The presence of these WBCs in the urine (pyuria) signifies inflammation or infection within the urinary tract, most commonly a Urinary Tract Infection (UTI).
This finding warrants further evaluation and likely treatment for a UTI, as it confirms an inflammatory response in the urinary system.

Option A: Oliguria is a clinical sign of low urine output (e.g., less than 400 mL/day), which is a measure of volume. The leukocyte esterase test is a chemical analysis that detects an enzyme from white blood cells, not urine quantity.
Option B: Dysuria is the subjective symptom of painful or burning urination, which is reported by the patient. The leukocyte esterase test is an objective laboratory finding, not a measure of a patient's symptoms.
Option C: Haematuria is the presence of red blood cells (RBCs) in the urine. This is detected by a different pad on the urine dipstick (the 'blood' or 'heme' pad), not the leukocyte esterase pad.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Interpretation of urinalysis results for UTI diagnosis as background academic context rather than a clinical decision trigger.
Nurses frequently perform urine dipstick tests as a rapid screening tool for UTIs at the point of care, allowing for prompt initiation of further diagnostics.
A positive leukocyte esterase result should prompt the nurse to ensure the specimen is sent for urine culture and sensitivity testing, and to anticipate physician orders for antibiotic therapy.
Patient education is key; the nurse should instruct the patient on how to obtain a proper clean-catch midstream urine sample to prevent contamination and ensure accurate results.

How to Approach the Question

This is a factual recall question requiring knowledge of basic laboratory test interpretation.
First, identify the key term in the question: 'leukocyte esterase test'.
Break down the term: 'Leukocyte' refers to white blood cells (WBCs). 'Esterase' is an enzyme they release.
Connect the presence of leukocyte esterase to the presence of WBCs in the urine.
Scan the options to find the correct medical term for WBCs in the urine.
Match 'WBCs in urine' to 'pyuria'. Eliminate the other options: 'oliguria' (low urine volume), 'dysuria' (painful urination symptom), and 'haematuria' (red blood cells in urine).

Concept Tested & Keywords

QdCmGQYNC6a4E23XwSRW00

E6 Medicine Harrison 22e Part 1 p. 1133-1135

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 1069-1071

E6 Gynecology Williams p. 80-104

Practise the full UPUMS Nsg officer-2023

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