Carbon monoxide poisoning causes:JIPMER 11; AIIMS 14
**Core Concept**
Carbon monoxide poisoning is a toxic condition resulting from the inhalation of carbon monoxide (CO), a colorless, odorless gas that binds to hemoglobin in red blood cells, forming carboxyhemoglobin. This reduces the oxygen-carrying capacity of blood, leading to tissue hypoxia.
**Why the Correct Answer is Right**
Carbon monoxide binds to the iron atom in hemoglobin with a higher affinity than oxygen, forming carboxyhemoglobin. This reduces the hemoglobin's ability to bind oxygen, leading to tissue hypoxia. The half-life of carboxyhemoglobin is approximately 4-6 hours, but it can be accelerated by oxygen therapy. The presence of carbon monoxide poisoning can be confirmed by measuring the carboxyhemoglobin level in the blood.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because carbon monoxide poisoning does not primarily cause renal failure. While it can lead to multi-organ failure, the primary effect is on the cardiovascular system due to tissue hypoxia.
**Option B:** This option is incorrect because carbon monoxide poisoning does not primarily cause liver failure. While it can lead to multi-organ failure, the primary effect is on the cardiovascular system due to tissue hypoxia.
**Option C:** This option is incorrect because carbon monoxide poisoning does not primarily cause respiratory failure. While it can lead to respiratory distress, the primary effect is on the cardiovascular system due to tissue hypoxia.
**Clinical Pearl / High-Yield Fact**
Carbon monoxide poisoning can be prevented by using carbon monoxide detectors in homes and workplaces. It is also essential to maintain vehicles properly, as a faulty exhaust system can lead to carbon monoxide buildup.
**Correct Answer: C. It causes tissue hypoxia.**