I-85. A 54-year-old man is admitted to the hospital with severe nausea, vomiting, and diarrhea. These symptoms began 36 h ago. He briefly improved for a few hours yesterday, but today has progressively worsened. He states he is concerned about possible poisoning because of his role in espionage and counterterrorism for the U.S. government. He met with an informant 2 days previously at a hotel bar, where he drank three cups of coffee but did not eat. He does state that he left the table to place a phone call during the meeting and is concerned that his coffee may have been contaminated. He otherwise is quite healthy and takes no medications. On physical examination, he appears ill. The vital signs are: blood pressure 98/60 mmHg, heart rate 112 beats/min, respiratory rate 24 breaths/min, SaO2 94%, and temperature 37.4°C. Head, ears, eyes, nose, and throat examination shows pale mucous membranes. Cardiovascular examination is tachycardic, but regular. His lungs are clear. The abdomen is slightly distended with hyperactive bowel sounds. There is no tenderness or rebound. Extremities show no edema, but a few scattered petechiae are present. Neurologic examination is normal. A complete blood count is performed. The results are: white blood cell (WBC) count 150/mkL, red blood cell count 1.5/mkL, hemoglobin 4.5 g/dL, hematocrit 15%, platelet count 11,000/mkL. The differential on the WBC count is 98% PMNs, 2% monocytes, and 0% lymphocytes. A blood sample is held for HLA testing. A urine sample is positive for the presence of radioactive isotopes, which are determined to be polonium-210, a strong emitter of alpha radiation. The mode of exposure is presumed to be ingestion. What is the best approach to the treatment of this patient?
A. Bone marrow transplantation
B. Gastric lavage
C. Potassium iodide
D. Supportive care only
E. Supportive care and dimercaprol
The answer is E. (Chap. 216) This patient has been exposed to radioactive polonium- 210, a strong emitter of alpha radiation, which can be used as a calibration source or neutron source in nuclear reactors. The patient is presenting with acute radiation sickness after an unknown ingestion amount. However, his symptoms began early after ingestion, and there is also severe bone marrow suppression, suggesting that the dose was >2 Gy. Polonium accumulates in the spleen and kidneys. In addition to supportive care with transfusions and colony-stimulating factors, chelation with dimercaprol should be attempted as polonium has a radiologic half-life of 138.4 days and a biologic half-life of 60 days. A bone marrow transplant could be considered if his bone marrow fails to recover. The presumed ingestion occurred >36 h previously, and a gastric lavage is unlikely to be helpful. Potassium iodide is useful in radioactive iodine poisoning or overdose.