Why is a hyperberic chamber preferred to an oxygen mask in Carbon Monoxide poisioning?

Answer 1

Hyperbaric chamber provides 100% oxygen all the time to cells starved by carbon monoxide poisoning - especially brain cells to prevent further damage and possibly death.

What I said is a nice summary of the paramedic's posting.

Answer 2

It is necessary to force carbon monoxide away from the hemoglobin which it attaches its self to. Carbon monoxide acts like an oxygen molecule and attaches itself to the red blood cells. As long as the CO molecule is on the red cell, O2 cannot attach, thus the cell starves for O2. In order to force CO off the red cell you must increase the atmospheric pressure (which the chamber does) and the CO is then forced away from the red cell and back into the blood, carried to the lungs and released from the body.

By treating with O2 only the Co continues to occupy the space on the red cell, thus not allowing the O2 to attach. Many treatments use both hyperbaric and O2 at the same time.

A simplistic explanation, I know, but I hope it helps.