The confirmatory test for diagnosis of Tuberculosis Chest?

Appeared in: WCL Staff Nurse - 2019

Explanation

Sputum culture is the gold standard for confirming a diagnosis of active pulmonary tuberculosis.
It provides definitive proof by isolating and growing live Mycobacterium tuberculosis from a patient's sputum sample.
A positive culture allows for further testing to determine which antibiotics the specific strain of bacteria is sensitive to (drug susceptibility testing), guiding effective treatment.

Option B: Bronchoscopy is a procedure to collect a respiratory sample (e.g., bronchoalveolar lavage) when a patient cannot produce sputum. It is a sample collection method, not the diagnostic test itself.
Option C: The Tuberculin (Mantoux) test is a screening tool for TB infection (latent TB), not a confirmatory test for active TB disease. It detects an immune response, not the presence of live bacteria.
Option D: A 'Saline Test' is not a recognized diagnostic test for tuberculosis. Nebulized hypertonic saline can be used to induce sputum, but it is a preparatory step, not the test.

Clinical Relevance

Nursing practice connection: Use the key finding related to Confirmatory diagnosis of pulmonary tuberculosis to guide bedside assessment, documentation, and the next nursing action.
Nurses play a crucial role in obtaining high-quality sputum samples for diagnosis. This involves instructing the patient to provide an early morning, deep-cough specimen, not just saliva.
Accurate labeling, storage, and timely transport of the specimen to the laboratory are essential nursing responsibilities to prevent false-negative results.
Patient education regarding the importance of completing the full course of anti-tubercular therapy is a key nursing intervention to prevent the development of drug-resistant TB.

How to Approach the Question

First, identify the key term in the question: 'confirmatory test'. This asks for the most definitive, gold-standard method of diagnosis.
Analyze each option's role in the diagnostic process.
Recognize that a 'Tuberculin Test' is for screening for infection, not confirming active disease.
Understand that 'Bronchoscopy' is a procedure to obtain a sample, not the test performed on the sample.
Eliminate 'Saline Test' as it's not a standard diagnostic test name.
Conclude that 'Sputum Culture' is the only option that definitively confirms the presence of live, active bacteria, making it the confirmatory test.

Concept Tested & Keywords

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E6 Microbiology Essentials Sastry 4e Part 2 p. 157-159

E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart B (pp 202-403 of 604) p. 23-25

E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 257-259

Practise the full WCL Staff Nurse - 2019

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