Carbon monoxide is a colorless, odorless gas. Carbonaceous materials don’t burn completely and release it. It is odourless and tasteless and victims often die before realizing that they are poisoned. Sources of carbon monoxide are plenty. Besides carbon dioxide, it is the most common pollutant in the lower environment. Effects of carbon monoxide poisoning vary in humans.

CO poisoning in the US causes over 40,000 cases yearly. Fatality rates due to CO toxicity range from 0.5 to 1.0 per 1,000,000 persons. CO may be the cause of half of all fatal poisonings. It is a major cause of death in fire victims too. Nearly 30% to 40% die before reaching the hospital. Of hospitalized victims, around 2% die, 10% recover partially. And 23% to 47% face delayed neurologic effects.

Carbon monoxide (CO) gets into the body through the lungs. It can harm the lung tissue directly, without the necessity to move through the blood. In other parts of the body, CO travels via hemoglobin. As the concentration of carboxyhemoglobin (COHgb) increases, blood vessels in brain expand, and flow of blood to heart and capillary increases. But if exposure continues, breathing slows down from lack of oxygen to the brain. Irregular heartbeats also occur, and they often cause death in CO poisoning. Evidence shows that damage to heart muscle starts when 20% CO combines with Hgb. For most animals dying from CO, the main causes are lack of oxygen and poor blood flow during the poisoning incident itself.

Carbon monoxide (CO) poisoning happens when CO attaches to hemoglobin, a protein that carries oxygen throughout the body. However, CO bonds with hemoglobin 220% more easily than oxygen leading to the formation of carboxyhemoglobin (COHb), thereby reducing the ability of hemoglobin to transport oxygen. This shifts the oxyhemoglobin curve to the left. CO also binds to cytochrome c oxidase, an enzyme in mitochondria blocking cellular respiration. These effects cause lower tissue and intracellular oxygen levels. Blood oxygen levels appear normal, but oxygen cannot reach cells properly.

Patients with carbon monoxide poisoning have a diffeerrential outlook. It depends on the severity of poisoning, and other health issues. Those suffering with abnormal brain scans typically have a bad outcome along with patients who have ongoing neurological issues.

Carbon monoxide exposure can harm thinking skills. Hyperbaric oxygen treatments help some patients avoid these thinking issues.

Carbon monoxide toxicity displays many symptoms. These often get confused with viral infections. Nausea, vertigo, and headaches are common signs. But in winter, fatigue, confusion, depression, breathing trouble, chest pains, and hallucinations can lead to confusion. Prolonged exposure to CO may gradually cause reduced cognition, mental issues, and loss of tooth. Examining about potential exposures is key for proper diagnosis.

Vital signs:

Vital signs of carbon monoxide may include

Hypotension/hypertension

Tachycardia

Hyperthermia

Tachypnea

Presence of cherry-red skin is a traditional sign of CO poisoning. Pallor may be present very commonly.

Ophthalmologic findings include bright retinal veins, retinal hemorrhage, homonymous hemianopsia, papilledema, noncardiogenic pulmonary edema.

Neuropsychiatric or neurologic findings include impaired judgement, emotional lability, memory disturbance, stupor, coma, disorders of movement, gait, apraxia, brisk reflexes, tic disorders, agnosia, psychosis, vestibular and hearing dysfunction.

• Amnesia
• Irritability
• Memory loss
• Speech deficit
• Depression
• Parkinson disease
• Cortical blindness

Assessment and stabilization: Then, using non-rebreather mask, delivering 100% extra oxygen, reducing carboxyhemoglobin half-life, and boosting tissue enchance oxygenation. This helps decrease the harmful effects of carbon monoxide on the patient’s body, allowing proper oxygen supply.

The patient should be moved quickly to open air, away from sources of CO exposure, ensuring safety. Ensure rapid checking for breathing, and circulation. A non-rebreather mask can be used to deliver 100% extra oxygen. This reduces the half-life of carboxyhemoglobin and boosts tissue oxygenation, which further helps to limit the harmful effects of carbon monoxide by allowing proper oxygen supply to the body.

Confirmation of diagnosis: This involves measuring the levels of carboxyhemoglobin. This is measured by performing blood gas analysis or using pulse CO-oximetry.

Oxygen therapy: In case of severe CO poisoning, neurological symptoms, or chronic effects, hyperbaric oxygen therapy (HBOT) may be employed. HBOT delivers pure oxygen at higher pressure. This reduces tissue oxygen lack, removes CO faster, and prevents delayed neurological damage. Ensure HBOT is provided by trained medical staff.

Emergency Medicine

Carbon monoxide (CO) poisoning can be prevented by increasing the circulation of air in the indoors. CO detectors should be placed near sources like furnaces and water heaters. Proper maintenance of fuel-burning appliances should be ensured. Usage of electric or solar-powered devices may be helpful. Educate people about risks of CO toxicity, and treatment. CO safety codes and standards for buildings should be followed. Get routine inspections and maintenance for appliances like boilers and furnaces to prevent incomplete combustion that produces more CO.

Emergency Medicine

Treatment with medicines is not available for carbon monoxide toxicity.

Emergency Medicine

• Prehospital care: Caring for patients with carbon monoxide poisoning begins with removing them from the exposed area. Next, give oxygen therapy and intubate the patient if needed. Early blood samples should be diagnosed for accurate poisoning levels. Estimate how long the patient was exposed. Minimize physical activity to reduce oxygen demand by tissues. Early blood testing helps get precise poisoning measurements.
• Hyperbaric oxygen therapy: Poisoning from carbon monoxide gets treated with extra oxygen therapy, often in hyperbaric chambers. This can be repeated three times depending on the condition of the patient to ensure a better outcome. However, even after initial treatment, up to four in ten patients may develop brain difficulties that require specialized neuropsychological testing.

Emergency Medicine

Carbon monoxide poisoning is dangerous. It causes symptoms like headache, dizziness, nausea, confusion, weakness, and unconsciousness. Doctors check exposure levels and symptoms. Treatment helps lower CO levels, relieve symptoms, and stop further damage. They remove you from the source, give oxygen, and use hyperbaric oxygen therapy for severe cases. Installing CO detectors, maintaining appliances, improving ventilation, and spreading awareness can prevent future exposure.