Arrange the steps for a Rapid Diagnostic Test (RDT) for HIV in the correct order:

A. Apply the patient's blood to the test strip

B. Wait for the specified time

C. Observe the test lines for HIV antibodies

D. Add a buffer solution to the sample well

1. A

   ADBC

2. B

   DACB

3. C

   CDAB

4. D

   CDBA

Appeared in: MP NHM CHO-2024 (Shift-1)

Explanation

• The correct sequence for a lateral flow immunoassay like an HIV RDT is to first apply the specimen, then the buffer, wait for the reaction, and finally read the result.
• Step A (Apply Blood): This is the initial step to introduce the patient's sample to the test device.
• Step D (Add Buffer): The buffer is added immediately after the blood to facilitate capillary flow of the sample across the test membrane.
• Step B (Wait): A specific incubation period is required to allow for the antigen-antibody reaction and for the control line to form.
• Step C (Observe Lines): Reading the test and control lines is the final step to interpret the result.

Why Other Options Were Wrong

• Option B: This sequence (DACB) incorrectly places the addition of buffer (D) before the application of the blood sample (A). The buffer is meant to act on the sample, so the sample must be applied first.
• Option C: This sequence (CDAB) incorrectly starts with observing the test lines (C). Results can only be observed after the test has been performed.
• Option D: This sequence (CDBA) incorrectly starts with observing the test lines (C). Results cannot be read before the sample is applied and the reaction time has passed.

Related Visual

• Visual 1: Infographic - A step-by-step visual guide showing the four stages of performing an HIV RDT: 1. Pricking the finger and applying a drop of blood. 2. Adding the buffer solution. 3. A clock icon indicating the waiting time. 4. An image of the test cassette showing negative, positive, and invalid results.

Clinical Relevance

• Nursing practice connection: Safe nursing care depends on performing Procedural steps for performing a Rapid Diagnostic Test (RDT) for HIV in the correct sequence, documenting the action clearly, and monitoring for the expected response.
• Correctly performing an RDT is a critical nursing skill for point-of-care testing, ensuring accurate screening results. Procedural errors can lead to false negatives or false positives, with significant consequences for the patient.
• Nurses play a vital role in pre-test and post-test counseling, which is mandatory for HIV testing in India. This includes explaining the test, ensuring informed consent, interpreting results, and linking patients to care.
• What if? If a nurse reads the result after the maximum specified time (e.g., at 40 minutes when the instructions say read by 20 minutes), the result is considered invalid. A faint line appearing after the reading window may be a false positive, and the test must be repeated.

How to Approach the Question

• First, identify the goal of the question: to find the correct sequence of a medical procedure (HIV RDT).
• Think logically about how any diagnostic test strip works. The sample must be applied first.
• Consider the function of each component. The 'buffer' is a solution that helps the 'blood' sample move. Therefore, the buffer must be added after the blood.
• Recognize that 'waiting' for a reaction is a necessary step before a result can be 'observed'.
• Assemble the steps in a logical order: Apply sample (A), add buffer to help it move (D), wait for the reaction (B), and finally, read the result (C).
• Compare your derived sequence (ADBC) with the given options to find the correct answer.

Concept Tested & Keywords

• Concept Tested: Procedural steps for performing a Rapid Diagnostic Test (RDT) for HIV.
• Stem keywords: Rapid Diagnostic Test, RDT, HIV, correct order, steps
• Lead-in keywords: Arrange

Question ID

QR48yIZPqeD5_FxvE4EijZ

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