Nederlands tijdschrift voor geneeskunde
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Measurement of cardiac troponins (cTnT and cTnI), the only cardiac specific biomarkers available, is the gold standard in diagnosing acute coronary syndrome. Due to the recent introduction of more sensitive methods i.e. the high-sensitivity troponin assays, the diagnostic cut-off concentrations have very recently been established. We describe two male patients who presented at the emergency department with acute chest pain, but in whom clear evidence for a myocardial infarction in the ST segment of the EKG was lacking. ⋯ Case 2 shows that the diagnosis of acute myocardial infarction should be accompanied by a typical rise or fall of troponin concentrations. The latest insights into high-sensitivity cardiac troponin assays are discussed in this article. We focus specifically on sensitivity and specificity, reference values obtained from a healthy control group, and the reference change value required to detect acute myocardial infarction.
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Since 2011, cobalt and chromium blood levels are measured in patients with a metal-on-metal hip implant (MoM prosthesis). In this article we discuss the health risks that are related to chronically elevated blood cobalt concentrations induced by abnormal wear and corrosion of the MoM prosthesis. Only a few patients who have systemic symptoms of poisoning, besides local symptoms around the failing MoM prosthesis, have been described in the literature. ⋯ In patients with a normal kidney function, the cobalt blood levels rapidly decrease and symptoms of cobalt intoxication subside. Chelation therapy should be restricted to those patients who are unable to undergo removal of the prosthesis immediately due to their medical condition. This can for example be because of a severe cobalt-induced cardiomyopathy.
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Not all questions concerning therapeutic effects in medical research can be answered satisfactorily by standard trials. The stepped wedge cluster design is a special form of randomised study in which an intervention at group level is implemented in stages. ⋯ The statistical analysis of cluster trials should account for the fact that individuals within clusters may show many similarities. Ethical aspects of stepped wedge design should be considered carefully, especially when obtaining individual informed consent is not possible.
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Ned Tijdschr Geneeskd · Jan 2012
Review[Down with odds ratios: risk ratios in cohort studies and randomised clinical trials].
Various effect measures are available for quantifying the relationship between an intervention or a risk factor and an outcome, such as the risk ratio and the odds ratio. Odds ratios are intended for use in case-control studies in which they are an appropriate measure for estimating the relative risk; however, this measure is also often presented in cohort studies and in randomized clinical trials. ⋯ For cohort studies and randomized clinical trials, however, there are methods to estimate adjusted risk ratios; these include the Mantel-Haenszel method, log-binomial regression, Poisson regression with robust standard error, and 'doubling of cases' method with robust standard error. To avoid misinterpretation of odds ratios, risk ratios should be calculated in cohort studies and randomized clinical trials.
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Frostbite injuries rarely occur in healthy Dutch persons. However, as the number of people engaging in winter and outdoor activities and travelling to high altitudes increases, the risk of frostbite also increases. ⋯ Iloprost infusion and possibly (r)tPA are indicated if a patient presents within 24 hours after the tissue has thawed and the injury is such that severe morbidity can be expected. If the patient presents after this time period, hyperbaric oxygen therapy may be considered; however, the evidence available on this type of treatment is limited.