Toxicology: sample from gastric lavage: practice question

A Forensic Medicine question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Forensic Medicine · Toxicology: sample from gastric lavage

Sample item

A man brought with suspected homicidal poisoning after a family dispute needs gastric lavage. How should the lavage specimen be handled?

AKeep the first aspirate separately in a labelled, sealed container and hand it to the police against a receiptBKeep the aspirate unlabelled in the ward until the police ask for itCPool all washings together to obtain a larger volume for the laboratoryDDiscard the first aspirate and keep only the later, clearer washings

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Keep the first aspirate separately in a labelled, sealed container and hand it to the police against a receipt

The first aspirate holds the highest concentration of poison and is the most valuable exhibit. It is collected before lavage fluid dilutes it, sealed, labelled and handed over with a signed receipt to preserve the chain of custody.

Option by option

A. Keep the first aspirate separately in a labelled, sealed container and hand it to the police against a receipt (correct)
Correct. The undiluted first aspirate is preserved as evidence.
B. Keep the aspirate unlabelled in the ward until the police ask for it
Unlabelled, unsecured material breaks the chain of custody.
C. Pool all washings together to obtain a larger volume for the laboratory
Pooling dilutes the poison and weakens the analytical value.
D. Discard the first aspirate and keep only the later, clearer washings
The first aspirate is the one that carries the poison, so it must not be discarded.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Forensic Medicine question

What is the answer to this Forensic Medicine question?

The best answer is A, Keep the first aspirate separately in a labelled, sealed container and hand it to the police against a receipt. The first aspirate holds the highest concentration of poison and is the most valuable exhibit.

Why is "Keep the aspirate unlabelled in the ward until the police ask for it" not the answer?

Unlabelled, unsecured material breaks the chain of custody.

Why is "Pool all washings together to obtain a larger volume for the laborato…" not the answer?

Pooling dilutes the poison and weakens the analytical value.

Why is "Discard the first aspirate and keep only the later, clearer washings" not the answer?

The first aspirate is the one that carries the poison, so it must not be discarded.

What concept does this question test?

It tests Toxicology: sample from gastric lavage in Forensic Medicine. It is collected before lavage fluid dilutes it, sealed, labelled and handed over with a signed receipt to preserve the chain of custody.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Toxicology: sample from gastric lavage?

Learn postmortem changes with their timelines, and toxicology as poison, sign, test and antidote. Then use the flashcards and the other Forensic Medicine questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.