The antidote for Carbon monoxide is?

Appeared in: SCTIMST Staff Nurse - 2015 (Set-B)

Explanation

Oxygen is the primary and definitive antidote for carbon monoxide (CO) poisoning.
CO has an affinity for hemoglobin that is 200-250 times greater than that of oxygen, forming stable carboxyhemoglobin (COHb) which leads to tissue hypoxia.
Administering 100% high-flow oxygen reduces the half-life of COHb from 4-6 hours on room air to about 60-90 minutes by competitively displacing CO from hemoglobin.
For severe cases, hyperbaric oxygen (HBO) therapy can be used to further decrease the COHb half-life to 20-30 minutes.

Option A: Atropine is an anticholinergic agent. It works by blocking acetylcholine receptors and has no effect on the binding of carbon monoxide to hemoglobin.
Option B: Vinegar is a weak solution of acetic acid. It has no role as a systemic antidote and would be harmful if ingested in large quantities.
Option C: Calcium gluconate does not interact with carbon monoxide or its binding to hemoglobin. Its mechanism is related to stabilizing cell membranes or replenishing calcium.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Antidote for Carbon Monoxide Poisoning as background academic context rather than a clinical decision trigger.
The immediate nursing priority for a patient with suspected CO poisoning is to remove them from the source of exposure and administer 100% oxygen via a non-rebreather mask.
A standard pulse oximeter is unreliable in CO poisoning because it cannot differentiate carboxyhemoglobin from oxyhemoglobin, often resulting in a falsely normal or high oxygen saturation reading. Diagnosis requires a co-oximetry blood test to measure COHb levels.
What if? If the patient is pregnant, the threshold for considering hyperbaric oxygen (HBO) therapy is much lower (COHb level greater than 15%). This is because the fetus is extremely sensitive to hypoxia, and fetal hemoglobin has an even higher affinity for CO than adult hemoglobin.

How to Approach the Question

First, identify the key terms in the question: 'antidote' and 'Carbon monoxide'. This is a direct factual recall question.
Access your knowledge of toxicology and common antidotes.
Evaluate each option based on its known therapeutic use.
Recall that Atropine is for organophosphate/cholinergic poisoning.
Recognize that Vinegar has no role as a systemic antidote.
Recall that Calcium Gluconate is used for electrolyte imbalances or specific poisonings like CCB overdose.

Concept Tested & Keywords

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E6 Nelson Textbook of Pediatrics(2024) — Volume 1 pp. 752-754, 751-753

Practise the full SCTIMST Staff Nurse - 2015 (Set-B)

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