Review Question - QID 212506

This patient is presenting after being rescued from a fire with confusion, headache, nausea, vomiting, and flushed skin suggesting a diagnosis of carbon monoxide poisoning which should be treated with 100% oxygen.

Carbon monoxide exposure is common in fires and in patients who heat their house with an old-fashioned wood stove. Carbon monoxide binds to hemoglobin with a higher affinity than oxygen thus displacing it leading to symptoms. Carbon monoxide poisoning presents with confusion, headache, altered mental status, nausea, vomiting, and cherry-red skin. Pulse oximetry is often normal in these patients as the device detects hemoglobin bound to oxygen or carbon monoxide similarly. A carboxyhemoglobin level can be obtained to confirm the diagnosis in these patients; however, patients presenting with a clinical picture supportive of carbon monoxide poisoning should be treated with 100% (or hyperbaric) oxygen. Sequelae of carbon monoxide poisoning should be treated supportively, including dantrolene for increased muscle activity or benzodiazepines for seizure activity.

Incorrect Answers:
Answer 2: CT scan of the head would be indicated if a patient presented with head trauma followed by altered mental status, nausea, and vomiting. This patient's neurological abnormalities, as well as his nausea and vomiting, can be explained by his carbon monoxide poisoning.

Answer 3: Hydroxocobalamin is the treatment of choice for cyanide poisoning which is also associated with exposure to fires. Patients will present with weakness, malaise, headache, dizziness, nausea, vomiting, and shortness of breath. Though this diagnosis is possible in this patient, a more likely diagnosis epidemiologically, and he lacks the classic almond bitter breath and the altered mental status. This patient will need empiric treatment for cyanide poisoning; however, a more dire intervention for the most likely diagnosis is putting the patient on oxygen to simultaneously and rapidly improve his respiratory status and treat his carbon monoxide poisoning.

Answer 4: Normal saline may be necessary to stabilize this patient’s blood pressure; however, his tachycardia is likely secondary to his pain and a direr initial intervention is stabilizing the patient’s respiratory status including administering oxygen for this patient’s carbon monoxide poisoning.

Answer 5: Ondansetron only treats this patient’s symptoms of nausea but does not address their respiratory status which should be treated promptly and prior to treating other concerns.

Bullet Summary:
The treatment of carbon monoxide poisoning is 100% oxygen.