Pseudohyperkalemia caused by fist clenching during phlebotomy
Article Abstract:
A case is described of a healthy, 55-year-old man who was found to have an elevated serum potassium level on several occasions when his blood was drawn at an outpatient clinic. He was referred to a medical center to be evaluated for possible kidney disease, and during his hospital stay, all five potassium tests, and all other examinations, were completely normal. After discharge he had follow-up tests at the outpatient clinic, and again his potassium was elevated. The patient happened to mention that when blood was drawn at the clinic, the technician used a tourniquet and instructed him to clench his fist. In the hospital, neither of these procedures was followed. A study to compare different phlebotomy (blood-drawing) procedures was designed using the patient and four healthy controls, men aged 31 to 59 years. It was discovered that use of the tourniquet alone had no effect on blood potassium results, but additional fist-clenching (either repeated clenching and unclenching or a constant hand-grip) did raise potassium readings by as much as 1.6 millimole per liter in the patient and the controls. Blood potassium was simultaneously measured in the other arm and was found in all cases to be normal and unaffected by the technique used in the opposite arm. It was concluded that exercise of the forearm muscles releases extra potassium into the local bloodstream. Since an erroneous reading indicative of high blood potassium (hyperkalemia) can lead to costly and unnecessary medical evaluations, the practice of clenching the fist during phlebotomy should be abandoned. The hand should remain relaxed, and if necessary a tourniquet may be used to aid in locating the vein. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: The New England Journal of Medicine
Subject: Health
ISSN: 0028-4793
Year: 1990
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Visceral infection caused by Leishmania tropica in veterans of Operation Desert Storm
Article Abstract:
Eight veterans of Operation Desert Storm who experienced fever, chronic fatigue, diarrhea and abdominal pain since returning from Saudi Arabia have been diagnosed with a form of visceral leishmaniasis. Leishmaniasis is caused by the protozoan Leishmania. Visceral leishmaniasis, which is also called kala-azar, is caused by Leishmania donovani. Symptoms include fever, emaciation, liver and spleen enlargement and reduced levels of all blood cells. The eight soldiers had very different symptoms, and bone marrow biopsies revealed infection by Leishmania tropica. This organism usually produces cutaneous (skin) disease. Five of the men responded to treatment for leishmaniasis. Leishmania can exist in humans in a dormant state, and incubation periods can be very long. Consequently, it should be included in the differential diagnosis when any veteran of Operation Desert Storm presents with similar symptoms.
Publication Name: The New England Journal of Medicine
Subject: Health
ISSN: 0028-4793
Year: 1993
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Aneurysm syndromes caused by mutations in the TGF-beta receptor
Article Abstract:
The clinical and molecular characterization of people presenting symptoms of the Loeys-Dietz syndrome was undertaken to distinguish them from the similar symptoms of vascular Ehlers-Danlos syndrome. Aggressive arterial aneurysms, such as thoracic aortic aneurysms and aortic dissection, are found to be caused by mutations in the genes encoding the transforming growth factor beta (TGF-beta) I or II, a distinguishing feature of the Loeys-Dietz syndrome.
Publication Name: The New England Journal of Medicine
Subject: Health
ISSN: 0028-4793
Year: 2006
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