injuries poisoning
Carbon Monoxide Poisoning
Symptoms and Signs of CO Poisoning
Carbon monoxide (CO) poisoning symptoms tend to correlate well with the patient’s peak blood carboxyhemoglobin levels. Many symptoms are nonspecific. Headache and nausea can begin when levels are 10 to 20%. Levels>20% commonly cause vague dizziness, generalized weakness, difficulty concentrating, and impaired judgment. 30% commonly cause dyspnea during exertion, chest pain (in patients with Overview of Coronary Artery Disease ), and confusion. Higher levels can cause syncope, seizures, and obtundation. Hypotension, coma, respiratory failure, and death may occur, usually when levels are>60%. Patients may also have many other symptoms, including visual deficits, abdominal pain, and focal neurologic deficits. If poisoning is severe, neuropsychiatric symptoms and signs (eg, dementia, psychosis, parkinsonism, chorea, amnestic syndromes) can develop days to weeks after exposure and become permanent. Because CO poisoning often results from house fires, patients may have concomitant airway injuries (see Smoke Inhalation ), which may increase risk of respiratory failure. 