Kolmonoxhemoglobin

Kolmonoxhemoglobin, commonly referred to in English as carboxyhemoglobin (COHb), is the compound formed when carbon monoxide (CO) binds to hemoglobin in red blood cells. It results from inhalation of CO from sources such as vehicle exhaust, tobacco smoke, faulty furnaces, gas heaters, and smoke from fires. COHb reduces the blood’s capacity to carry oxygen and impairs oxygen delivery to tissues.

Mechanism and effects: CO has a high affinity for hemoglobin, about 200 times greater than that of oxygen, leading to reduced oxygen-carrying capacity and a leftward shift of the oxyhemoglobin dissociation curve, which hampers release of oxygen to tissues. CO can also interfere with cellular respiration at higher concentrations. The net effect is tissue hypoxia, which can affect vital organs, particularly the brain and heart.

Clinical relevance and measurement: Symptoms of CO exposure correlate with COHb levels and duration of exposure. Mild elevations may cause headache and fatigue; higher levels can produce dizziness, confusion, nausea, and weakness; very high levels can lead to syncope, seizures, coma, or death. COHb is measured by co-oximetry in blood; standard pulse oximetry can overestimate oxygenation because it cannot distinguish COHb from oxyhemoglobin.

Treatment and prognosis: Management centers on removing the source of CO and delivering supplemental oxygen, typically 100% oxygen, to accelerate CO elimination. In severe cases, or in pregnancy, hyperbaric oxygen therapy may be considered. Most individuals recover with prompt treatment, but significant exposure can lead to lasting neurocognitive effects.

Prevention: Prevention focuses on proper ventilation, regular maintenance of combustion devices, avoiding smoking in enclosed spaces, and installing CO detectors in homes and workplaces.