What is seen in CO poisoning?
**Core Concept**
Carbon monoxide (CO) poisoning occurs when CO binds to hemoglobin in red blood cells, forming carboxyhemoglobin (COHb). This reduces the oxygen-carrying capacity of the blood, leading to tissue hypoxia.
**Why the Correct Answer is Right**
CO has a higher affinity for hemoglobin than oxygen, binding to the iron atom in the heme group. This results in the formation of COHb, which shifts the oxygen-hemoglobin dissociation curve to the left. As a result, the amount of oxygen released to tissues is reduced, leading to tissue hypoxia. The presence of COHb can be detected in the blood of individuals with CO poisoning.
**Why Each Wrong Option is Incorrect**
**Option A:** Cyanosis is not typically seen in CO poisoning, as the skin appears pink or cherry-red due to the presence of COHb.
**Option B:** CO poisoning does not primarily affect the respiratory system; however, it can lead to respiratory failure in severe cases.
**Option C:** While CO poisoning can cause neurological symptoms, it is not primarily a neurological disorder.
**Clinical Pearl / High-Yield Fact**
CO poisoning can be diagnosed using a carboxyhemoglobin level of 3% or higher, and treatment typically involves administering 100% oxygen.
**Correct Answer:** A. Cyanosis is not typically seen in CO poisoning.