Final answer:
Administering 100 percent oxygen helps displace carbon monoxide from the hemoglobin, restoring its ability to carry oxygen to tissues. Giving carbon dioxide is ineffective because it does not compete with carbon monoxide for binding to hemoglobin and cannot displace it to alleviate poisoning.
Step-by-step explanation:
The administration of 100 percent oxygen saves a patient from carbon monoxide poisoning by displacing carbon monoxide from its binding site on hemoglobin. Hemoglobin has a much higher affinity for carbon monoxide than for oxygen, which means in the presence of carbon monoxide (CO), it binds preferentially to hemoglobin, thereby preventing oxygen from attaching and being transported to the body's tissues. By administering a high concentration of oxygen, it promotes the dissociation of carbon monoxide from carboxyhemoglobin, turning it back into hemoglobin that can transport oxygen effectively.
Administering carbon dioxide (CO2) would not be an effective treatment for carbon monoxide poisoning because, unlike carbon monoxide, carbon dioxide readily associates and dissociates from hemoglobin without blocking oxygen's ability to bind. Furthermore, carbon dioxide does not have the same affinity for hemoglobin as carbon monoxide, so it would not displace carbon monoxide from hemoglobin to alleviate the poisoning.
When a patient inhales pure oxygen during treatment, the equilibrium shifts, prompting the release of carbon monoxide from hemoglobin, which then allows the hemoglobin to bind oxygen again. This shift leads to a significant reduction in the half-life of carboxyhemoglobin, facilitating a faster recovery for the patient.