1,721,141 research outputs found
Diagnostic strategies using myoglobin measurement in myocardial infarction.
No full textMyoglobin, a low molecular-weight heme protein (17800 D) present in both cardiac and skeletal muscle, is an old test with new perspectives. Advantages and disadvantages of myoglobin determination are well known. Myoglobin is the earliest known, commercially available, biochemical marker of acute myocardial infarction (AMI) and its rapid kinetics make it an early, good marker of reperfusion. However, since myoglobin is present in both skeletal and cardiac muscle, any damage to these muscle types results in its release into blood. Serum myoglobin levels are falsely elevated in conditions unrelated to AMI as skeletal muscle and neuromuscular disorders, renal failure, intramuscular injection, strenuous exercise, and after several toxins and drugs intake. New strategies for myoglobin measurement may resolve this limitation. These strategies include both the combined measurement of myoglobin and a skeletal specific marker (carbonic anhydrase III) or a cardiac specific marker (troponin I), as well as the myoglobin evaluation on serial samples. In particular, the diagnostic algorithm based on the combined measurement of myoglobin and troponin I, assuring a satisfactory analytical turnaround time, significantly improves the diagnostic efficiency of laboratory assessment of suspected AMI patients, allowing the successive monitoring of coronary reperfusion
Acute coronary syndrome without ST-segment elevation. Current guidelines
No full textCoronary-artery disease is the leading cause of death in western countries. Unstable angina and myocardial infarction without ST-segment elevation are now recognized as among the most frequent and important clinical manifestations of coronary-artery disease. The European and American professional societies have released guidelines on diagnosis, risk stratification and treatment of these disorders. These guidelines summarise current evidences and translate them in clinical practice. Most important changes relate to the inclusion of troponins into the risk stratification algorithm. In addition, some guidelines released by scientific committees of the laboratory area further define the quality specifications for cardiac troponin assays. Powerful tests, such as cardiac troponins, on which critical decisions will rest need highly reliable methods, quality control and external quality assurance schemes
Diagnostic strategies in myocardial infarction using myoglobin measurement.
No full textDetermination of myoglobin, a low molecular weight haeme protein (17.8 kDa), present in both cardiac and skeletal muscle, is an old test with new perspectives. Advantages and disadvantages of myoglobin determination are well known; recent availability of rapid and accurate methods for the assay of this protein has greatly enhanced interest in the clinical utilization of the test. However, since myoglobin is present in both skeletal and cardiac muscle, any damage to these muscle types results in its release in blood and, consequently, high levels of the protein are observed in conditions unrelated to acute myocardial infarction (AMI). New strategies for myoglobin measurement may resolve this limitation. These strategies include both the combined measurement of myoglobin and a skeletal specific marker (carbonic anhydrase III) or a cardiac specific marker (troponin I or T), as well as myoglobin evaluation on serial samples. In particular. the diagnostic algorithm based on combined measurement of myoglobin and troponins significantly improves diagnostic efficiency in laboratory assessment of suspected AMI patients. However, further efforts are necessary to improve the standardization of present methods for myoglobin measurement: the significant disagreement demonstrated between some commercially available assays should be carefully considered in clinical practic
Cardiac markers: present and future.
No full textIn the early twentieth century, acute myocardial infarction secondary to acute thrombotic coronary occlusion was considered a rare, fatal condition. Acute myocardial infarction is now one of the most-commmon serious illnesses in the industrialized world. Laboratory medicine now plays a crucial role in identifying risk factors, early events, and conditions triggering plaque rupture in coronary ischemic disease. However, the greatest progress in laboratory research has resulted from the discovery of new and more-promising biochemical markers of myocardial damage. The discovery of cardiac troponins, in particular, has heralded a new age in the diagnosis and treatment or management of a broad spectrum of diseases, grouped together under the heading of acute coronary syndrome, and including stable and unstable angina, and non-Q wave infarction to Q-wave infarction. Cardiac troponins, which are selectively released by damaged myocardiocytes, have a specificity that has not only allowed an improvement in the diagnosis of acute cardiac ischemic disorders, but has also enabled us to make a more-reliable stratification of risk and prediction of outcome. It is generally agreed that two biochemical markers should be used: an early marker (and we recommed myoglobin for this) and a definitive marker, which is cardiac troponin (I or T). Future research is likely to include the standardization of methods for measuring current markers, troponin I in particular, the assessment of rapid bedside tests, and the investigation of the relationship between cardiac markers and emerging immunological and coagulation parameters. Thrombogenesis is now recognized as important in the final process of coronary atherosclerosis, and new markers of thrombogenesis should be used to evaluate the risk of plaque rupture and to monitor the outcome of thrombolytic therapy. Moreover, recent vascular biology studies have provided information on the developmental stages of atherosclerosis and emphasized the importance of the endothelium as a modulator of vascular reactivity, atherogenesis, and plaque stability. The different types of laboratory test (biochemical, immunological, and coagulative) now available, should soon allow improvement in the diagnosis and therapy of ischemic coronary diseases
Cardiac markers: centralized or decentralized testing?
Full text linkTesting for the diagnosis of acute myocardial infarction and other diseases included in the spectrum of the "acute coronary syndrome" is rapidly changing from the traditional enzymatic assays to mass measurement bf more specific and sensitive markers (cardiac troponins, CK-MB and myoglobin). Several questions have arisen since the introduction of these new markers into the clinical setting: the choice of strategies for optimizing the utilization of biochemical assays combining different (early and specific) markers, a rationale for sampling specimens and the identification of clinically useful turnaround times. In particular, for achieving the last goal, attention has been directed toward near-patient testing for cardiac markers in addition to, or as a replacement for, traditional diagnostic methodologies. While qualitative methods for measuring cardiac markers at the bedside have some limitations which compromise their clinical usefulness, new quantitative devices offer a real alternative to decentralized testing. Regulatory and quality management issues related to near-patient testing, as well as the performance of recently introduced devices for a decentralized measurement of cardiac markers are reviewed
Utilization management: a European perspective.
No full textUtilization management (UM) in health care, based on the collection, assessment and monitoring of data pertaining to patient services and treatment, ultimately assures efficiency and effectiveness. The central role of laboratory services in modern medicine created the need to utilize UM programs in clinical laboratories in order to reduce costs, enhance efficiency and improve on quality for patients. Some UM programs have focused on improving efficiency by reducing the cost per test. Consolidation and networking have been proposed as opportunities to increase test volumes, thus achieving economy of scale, and a better ratio between test volumes and fulltime equivalent (FTE) staff. However, little evidence is available in the literature to demonstrate the efficiency of these models, and concern has been expressed regarding the possible increase in pre-analytical errors and the loss of efficient communication between clinicians and laboratory professionals. In Europe, we have seen an increasing emphasis on the importance of demand management strategies as the key to reducing costs and improving on quality in laboratory medicine. The cost of inappropriate requesting includes not only test consumables and reagents, but also additional consultations, treatment and investigations. A number of studies in literature describe strategies and initiatives designed to change and improve test requesting, but the following two items are mandatory for real improvement: a) the active involvement of requesting physicians and other stakeholders, including patients; and b) the use of combined interventions instead of a single strategy. Therefore, the use of approaches for demand management that considers pre-, within- and post-laboratory initiatives is on the increase in clinical laboratories throughout Europe
Requirements for improving quality in the measurement of bone markers
No full textBACKGROUND:
A number of biochemical assays readily detect molecules released from the bone matrix and collagen degradation in both serum and urine specimens. The variability of bone biochemical markers is still an issue of practical concern limiting their wider clinical use, and compromising the management of the individual patient. The aim of the present study was to define quality specifications of bone markers measurement in the total testing process.
METHODS:
The different sources of biological variability of biochemical bone marker were assessed according to the current knowledge and categorized as pre-analytical, intra-analytical and post-analytical.
RESULTS:
The identification of factors influencing bone marker measurements allowed recommendations to be made for decreasing pre- and intra-analytical variation in order to improve laboratory performance. The assessment of post-analytical sources of variation, moreover, involves the practical use of bone markers in identifying individual women at risk of fractures and the identification of non-responders, providing adequate limit value, least significant change value or optimal threshold of bone marker change.
CONCLUSIONS:
Laboratory services may improve the potential clinical applications of biochemical markers of bone remodeling by improving method standardization, defining and reducing pre-analytical and analytical variables and providing reports that specify analytical and biological variation or cut-off values, thus facilitating data interpretation or reports
- …
