Errors in transfusion: causes and measures to avoid them.

Clin Chem Lab Med. 2010 Aug;48(8):1075-7

Authors: Franchini M

Adverse events related to medical errors are common worldwide and largely unreported. However, they represent a serious problem within the health care community, resulting in avoidable loss of life and/or extremely high costs. Likewise, errors in transfusion medicine, which most frequently involve misidentification of the patient, not rarely may have life-threatening consequences. In this review, the errors related to blood transfusion are briefly summarized along with new technologies developed for improving blood safety.

PMID: 20578965 [PubMed - indexed for MEDLINE]

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Troponin revisited 2008: assay performance.

Clin Chem Lab Med. 2008;46(11):1489-500

Authors: Tate JR

Troponin quality specifications describing the pre-analytical, analytical and post-analytical performance of cardiac troponin (cTn) assays are important for both manufacturers of cTn assays and laboratories that routinely test for cTn. Pre-analytical requirements refer not only to acceptable sample type for analysis and the stability of cTn but also to the proper handling of specimens prior to analysis to avoid pre-analytical false positive results. Analytical issues that may contribute to differences between cTn assays include analytical sensitivity and imprecision at low cTn concentration, antibody specificity and immunoreactivity of plasma cTn forms, assay specificity and the presence of falsely positive and negative interferences, and for cTnI the lack of standardised measurement, all which may impact on patient cTn results. Current second generation cTnI and fourth generation cTnT assays generally have an imprecision of around 20% coefficient of variation (CV) at the 99th percentile of the reference population, which is greater than the recommended imprecision of 10% CV. As the next generation of more analytically sensitive cTn assays are developed it can be anticipated that cTn upper reference limits will decrease by approximately 10-fold. Monitoring assay imprecision at ultra low cTn concentrations will require that the laboratory uses a quality control close to this level and a negative control to monitor baseline drift. Establishment of cTn reference ranges will require reference populations to be cardio-healthy to enable differentiation from community populations who are at increased cardiovascular risk. Close collaboration between the laboratory and local clinicians is required to ensure adequate clinical validation of more sensitive cTn assays.

PMID: 18842109 [PubMed - indexed for MEDLINE]

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What is the value of B-type natriuretic peptide testing for diagnosis, prognosis or monitoring of critically ill adult patients in intensive care?

Clin Chem Lab Med. 2008;46(11):1524-32

Authors: Christenson RH

BACKGROUND: B-natriuretic peptide (BNP) and aminoterminal proBNP (NT-proBNP) are clinically useful for the diagnosis of decompensated heart failure and for prognosis in heart failure and acute coronary syndromes. Clinical use of these biomarkers in critically ill patients being treated in intensive care is not well established. METHODS: This is a narrative review of evidence identified searching MEDLINE with the strategy [(BNP OR NT-proBNP) AND (critical illness AND intensive care)]. Seven primary reports and two narrative reviews were retrieved. For completeness, literature from each of the following searches was reviewed: [(BNP OR NT-proBNP) AND (critical illness)] and [(BNP OR NT-proBNP) AND (intensive care)]. RESULTS: Primary literature used BNP and NT-proBNP for diagnosis, prognosis and monitoring. For diagnosis of acute lung injury in unselected intensive care patients and for diagnosis of heart failure in trauma patients, the biomarkers had low sensitivity and are of modest use. BNP and NT-proBNP were found to have a significant ability to prognosticate adverse outcomes in critically ill patients. A single paper examined the use of BNP as a non-invasive replacement for pulmonary capillary wedge pressure, finding little value. The impact of renal insufficiency on the markers was noted as a confounder in most studies. In the secondary searches, some preliminary data suggested a possible role for the natriuretic peptides in exclusion of a cardiac cause for certain conditions among intensive care unit (ICU) patients. However, the general findings were that the performance of BNP and NT-proBNP is unimpressive among ICU patients. CONCLUSIONS: Currently, utilization of BNP and NT-proBNP does not appear to provide much useful information or have a substantial role in the care of critically ill patients in intensive care.

PMID: 18847367 [PubMed - indexed for MEDLINE]

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The clinical impact of the universal diagnosis of myocardial infarction.

Clin Chem Lab Med. 2008;46(11):1485-8

Authors: Jaffe AS

BACKGROUND: All of the recent guidelines now endorse the use of troponin as the biomarker or choice for the diagnosis of acute myocardial infarction (AMI). METHODS: Review of the recent guidelines criteria. RESULTS: Rising and/or falling values of troponin in patients who appear to have ischemic heart disease will result in the diagnosis of AMI. The recent guidelines emphasize the use of the 99th percentile value for troponin and suggest it should be measurable with a high level of precision. They also suggest how to operationalize determining a significant change for patients who appear to have recurrent infarction and classify AMI into five subtypes. CONCLUSIONS: Understanding these criteria will be important to a consistent approach to the diagnosis of AMI in the future.

PMID: 19012516 [PubMed - indexed for MEDLINE]

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Clinical relevance of non-cardiac determinants of natriuretic peptide levels.

Clin Chem Lab Med. 2008;46(11):1515-23

Authors: Passino C, Poletti R, Fontana M, Vergaro G, Prontera C, Gabutti A, Giannoni A, Emdin M, Clerico A

There is evidence that natriuretic peptide (namely atrial and/or B-type natriuretic peptides) plasma concentration may be elevated in many clinical conditions besides cardiovascular diseases, the most frequent being lung diseases, renal and liver failure, acute cerebrovascular events, acute and chronic inflammatory diseases and certain metabolic and endocrine disorders. In general, increased circulating levels of natriuretic peptides (compared to the normal range of a healthy population) may be considered expression of activation of the neuro-endocrine system, which can be the cause or consequence of cardiac stressor events. Furthermore, some variables, such as gender and obesity, may affect natriuretic peptide secretion and plasma concentration by completely extra-cardiac mechanisms. Increased expression of the natriuretic peptide system, counteracting neuro-hormonal and immunological activation, may occur in many clinical conditions, as witnessed by the considerable number of diseases in which the natriuretic peptide system has been found to be altered. Several studies have demonstrated that higher circulating levels of natriuretic peptides represent a strong independent risk factor for major cardiovascular complications and/or death, even in extra-cardiac diseases. Because several of these diseases may be present in patients with left ventricular dysfunction, the possible influence on diagnostic and prognostic accuracy of natriuretic peptides in heart failure will be discussed.

PMID: 19012517 [PubMed - indexed for MEDLINE]

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Natriuretic peptide testing in emergency settings.

Clin Chem Lab Med. 2008;46(11):1543-9

Authors: Ordonez-Llanos J, Merce-Muntanola J, Santalo-Bel M

Acutely dyspneic patients are challenging, because their symptoms can be due to cardiac, pulmonary or other diseases. B-type natriuretic peptide testing offers higher diagnostic accuracy (85%-90%) than clinical assessments for identifying heart failure as the cause of dyspnea. On the other hand, the high clinical sensitivity and negative predictive value of natriuretic peptides permit to rule out heart failure with an accuracy > 90%. Natriuretic peptides are the most powerful, single prognostic markers of complications associated with acute dyspnea and permit the early recognition of high-risk patients. It has been shown that systematic natriuretic peptide testing reduces the economic expenses associated with clinical management of acutely dyspneic patients. Finally, whether these biomarkers could be used to guide heart failure therapy in the acute setting remains to be elucidated.

PMID: 19012518 [PubMed - indexed for MEDLINE]

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