Volume 5, Number 8; February 04, 2006
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Volume 5, Number 8; February 04, 2006 |
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84-year-old moonshine drinker with weakness.
Recommended reading:
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Patient:
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Session Handout:
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Clinical Question: 1) What is the clinically detectable threshold for chronic lead intoxication in adults?
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Readings:
Link Directly to Fulltext Article at Publisher <1> Unique Identifier [PMID]: 12041847 Authors: Sanborn MD. Abelsohn A. Campbell M. Weir E. Institution: Department of Family Medicine, McMaster University, Hamilton, Ont. msanborn@sbghc.on.ca Title: Identifying and managing adverse environmental health effects: 3. Lead exposure. [Review] [37 refs]
Source: CMAJ Canadian Medical Association Journal. 166(10):1287-92, 2002 May 14. Abstract: Lead levels in North American children and adults have declined in the past 3 decades, but lead persists in the environment in lead paint, old plumbing and contaminated soil. There are also a number of occupations and hobbies that carry a high risk of lead exposure. There is no evidence for a threshold below which lead has no adverse health effects. Blood lead levels previously considered safe are now known to cause subtle, chronic health effects. The health effects of lead exposure include developmental neurotoxicity, reproductive dysfunction and toxicity to the kidneys, blood and endocrine systems. Most lead exposures are preventable, and diagnosing lead poisoning is relatively simple compared with diagnosing health effects of exposures to other environmental toxins. Accurate assessment of lead poisoning requires specific knowledge of the sources, high-risk groups and relevant laboratory tests. In this article we review the multiple, systemic toxic effects of lead and provide current information on groups at risk, prevention, diagnosis and clinical treatment. We illustrate how the CH2OPD2 mnemonic (Community, Home, Hobbies, Occupation, Personal habits, Diet and Drugs) and specific screening questions are useful tools for physicians to quickly obtain an environmental exposure history and identify patients at high risk of lead exposure. By applying effective primary prevention, case-finding and treatment interventions for lead exposure, both the individual patient and the larger community reap the benefits of better health. [References: 37] Publication Type: Case Reports. Journal Article. Review.
Link Directly to Fulltext Article at Science Direct <6> Unique Identifier [PMID]: 9732886 Authors: Cheng Y. Schwartz J. Vokonas PS. Weiss ST. Aro A. Hu H. Institution: Department of Epidemiology, Harvard School of Public Health, Department of Veterans Affairs Outpatient Clinic, Boston, Massachusetts, USA. Title: Electrocardiographic conduction disturbances in association with low-level lead exposure (the Normative Aging Study).
Source: American Journal of Cardiology. 82(5):594-9, 1998 Sep 1. Abstract: Recent research indicates that cumulative exposure to lead may be more toxic than previously thought. This study was undertaken to examine the relation of low-level lead exposure to electrocardiographic (ECG) conduction disturbances among 775 men who participated in the Normative Aging Study (average age 68 years; range 48 to 93). We used K-x-ray fluorescence to measure lead levels in the tibia and patella, and graphite furnace atomic absorption spectroscopy to measure blood lead levels. The mean (SD) values for blood lead, tibia lead, and patella lead were 5.8 (3.4) microg/dl, 22.2 (13.4) microg/g, and 30.8 (19.2) microg/g, respectively. Bone lead levels were found to be positively associated with heart rate-corrected QT and QRS intervals, especially in younger men. Specifically, in men <65 years of age, a 10 microg/g increase in tibia lead was associated with an increase in the QT interval of 5.03 ms (95% confidence interval [CI], 0.83 to 9.22) and with an increase in the QRS interval of 4.83 ms (95% CI, 1.83 to 7.83) in multivariate regression models. In addition, an elevated bone lead level was found to be positively associated with an increased risk of intraventricular block in men <65 years of age and with an increased risk of atrioventricular (AV) block in men > or = 65 years of age. After adjustment for age and for serum high-density lipoprotein (HDL) level, a 10 microg/g increase in tibia lead was associated with an odds ratio (OR) of 2.23 (95% CI, 1.28 to 3.90) for intraventricular block in men <65 years of age and with an OR of 1.22 (95% CI, 1.02 to 1.47) for AV block in men > or = 65 years of age. Blood lead level was not associated with any of the ECG outcomes examined. The results suggest that cumulative exposure to lead, even at low levels, may depress cardiac conduction. Publication Type: Journal Article.
Link Directly to Fulltext article in Ovid <8> Unique Identifier [PMID]: 9065540 Authors: Bleecker ML. Lindgren KN. Ford DP. Institution: Center for Occupational and Environmental Neurology, Baltimore, MD 21211, USA. Title: Differential contribution of current and cumulative indices of lead dose to neuropsychological performance by age.
Source: Neurology. 48(3):639-45, 1997 Mar. Abstract: We examined measures of lead dose that reflect intensity of exposure and cumulative exposure for differential association with neuropsychological functional domains and with neuropsychological performance by age. Eighty active lead smelter workers assessed for verbal memory and visuomotoric skills had a mean (range) age of 44 (24-64) years, duration of employment of 20 (4-26) years, education of 8 (0-13) grades, current blood lead (B-Pb) of 26 microgPb dl(-1) (13-43), working lifetime weighted average blood lead (TWA) of 42 microgPb dl(-1) (17-57), working lifetime integrated blood lead (IBL) of 903 microgPb-yr dl(-1) (81-1,436) and bone lead (bone-Pb) of 41 microgPb (g bone mineral)(-1) (-12-90). Multiple linear regression after adjusting for age and education showed a significant amount of variance in verbal memory (Rey Auditory Verbal Learning Test and Verbal Paired Associates) explained only by measures of lead dose intensity, B-Pb, and TWA. Visuomotoric ability (Grooved Pegboard [GP] and Digit Symbol) had significant variance accounted for by measures of both lead dose intensity, TWA, and of cumulative lead dose, IBL, and bone-Pb. The relationship between bone-Pb and GP was curvilinear in older workers, with increasingly slower performance above a bone-Pb threshold of 20 microgPb (g bone mineral)(-1). Examination of age-related change in GP with exposure using IBL, a surrogate for cumulative lead dose in the brain, showed enhanced age-related change in older workers with high IBL. These findings suggest that the older nervous system provides a substrate more susceptible to the effects of chronic lead exposure. Publication Type: Journal Article.
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Resident Report / Department of Medicine & Grady Branch Library Emory University School of Medicine 2005 Edition Participating Faculty: Carlos Del Rio MD / Joyce Doyle MD / Lorenzo Difrancesco MD / Erich Folch MD / Alicia Hidron MD
Contact:
Karl Woodworth
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