A 58-year-old man presented to the emergency department (ED) via emergency medical services (EMS) with shortness of breath, lightheadedness, and nausea. Upon arrival to the ED, most of his symptoms had resolved. The patient reported that he had taken a two-hour flight into town the previous day and had spent an uneventful evening at a local hotel. He said that he began experiencing shortness of breath and lightheadedness soon after entering his rental vehicle an hour prior to presentation, explaining that he felt as if he “could not get any air.”
He denied chest pain, leg pain or swelling, abdominal pain, or recent illness. Medical history was significant for hypertension, for which he was taking losartan and amlodipine. He had no drug allergies, surgical history, or smoking history. Of note, when the hotel clerk got in the same rental vehicle to move it, he developed symptoms similar to those of the patient. As with the patient, the clerk’s symptoms quickly resolved after he got out of the vehicle.
The patient’s vital signs at examination included an oral temperature of 97.5°F; pulse, 62 beats/min; respiratory rate (RR), 18 breaths/min; blood pressure, 133/83 mm Hg; and O2 saturation, 100% on room air. He was alert and oriented, in no distress, easily conversational, and without diaphoresis. The lungs were clear to auscultation bilaterally, and there was no calf swelling, tenderness, or palpable cords. The remainder of the physical exam was normal.
Ancillary studies included a normal chest X-ray. An ECG demonstrated sinus bradycardia with a rate of 56 beats/min but no evidence of ischemia or right heart strain. Complete blood count, troponin I, D-dimer, and creatine phosphokinase (CPK) with MB fraction levels were all within normal limits. A serum chemistry panel was also within normal limits, except for a serum glucose level of 181 mg/dL. Venous co-oximetry showed a carboxyhemoglobin level of 0.0, and methemoglobin level of 0.5 gm% (normal range, 0.4-1.5).
Since both the patient’s and hotel clerk’s symptoms started when each was in the rental car, the patient was questioned about the vehicle and its contents. The car was a late-model rental in good condition per report. The patient informed the treating emergency physician that he worked as a decorative cake salesman and had brought cake samples with him to display at a trade show. He further stated that he had left these samples in the car overnight, packed in dry ice.
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