This is when a patient’s pCO2 is greater than 40. That means they are not breathing enough to meet their body’s demands to get rid of CO2. CO2 is produced as a waste product in metabolism in the body and it is the lungs’ job to remove CO2 when we exhale. If CO2 builds up in our system, it can also be called hypoventilation or “under breathing”. Normal kidneys will try to produce HCO3 to compensate for (or neutralize) the high CO2 which acts as an acid. If the CO2 builds up quickly or too high, people get “CO2 narcosis” and can act drunk or even stop breathing altogether. This can happen despite the kidneys trying to compensate as the CO2 affects the brain more rapidly than the kidneys can correct it. Alternatively, in some people with lung disease or neuromuscular weakness, the CO2 can rise slowly enough that the brain adapts and they act normal even at very high pCO2 in the blood stream. So, the general rule of thumb is that a patient that has a pCO2>60 will be confused or even unconscious if it has risen quickly. If they are not altered mentally, this change has occurred over weeks, months or even years.
Better breathing through understanding…