CURRENT Essentials of Critical Care.pdf

Chapter 17 Environmental Injuries 247■■■Carbon Monoxide (CO) PoisoningEssentials of Diagnosis• Headache, confusion, neuropsychological impairment, generalizedmalaise, fatigue, nausea, vomiting, chest pain• Tachycardia, hypotension, focal and non-focal neurologicalfindings; patients do not have cyanosis; if severe, shock, stupor,coma• Electrocardiogram (ECG) changes of ischemia in susceptible patients• May be accidental (operation of motor vehicles in enclosedspace, malfunctioning furnaces), concomitant with smoke inhalation,deliberate suicide attempt• Alcohol, drugs associated with poisoning and death; most commonpoison-related death in United States• CO binds to tightly to hemoglobin, also increases O 2 affinity tohemoglobin, resulting in impaired O 2 delivery; also may be intracellulartoxinDifferential Diagnosis• Drug overdose• Hypoxemia• Cyanide toxicity• Effects of smoke inhalationTreatment• Supportive care, especially if cardiovascular compromise,smoke inhalation, burns• High concentration of inhaled oxygen speeds elimination of carbonmonoxide (use non-rebreather O 2 mask or endotracheal intubationwith 100% O 2 )• Hyperbaric 100% O 2 increases rate of CO elimination; clinicalvalue unclear• Transfusion of packed red blood cells may be helpful; considerexchange transfusions in severe toxicity■ PearlThe pulse oximeter is unable to distinguish carboxyhemoglobin fromoxyhemoglobin; blood must be sent for carboxyhemoglobin concentration.ReferenceGorman D et al: The clinical toxicology of carbon monoxide. Toxicology2003;187:25. [PMID: 12679050]