Pleural effusion, defined as excess fluid in the pleural space, can complicate the course of a large and pathologically diverse range of pulmonary and non-pulmonary diseases. Laboratory analysis of pleural fluid provides much useful information for the clinician whose diagnostic challenge is the patient presenting...

The anion gap (AG) is a calculated parameter derived from measured serum/plasma electrolyte concentrations. The clinical value of this calculated parameter is the main focus of this article. Both increased and reduced anion gap have clinical significance, but the deviation from normal that has most clinical...

Recent studies of D-dimer as a “rule-out” test for deep venous thrombosis (DVT) frequently have used duplex ultrasound rather than venography as the gold standard. Because duplex ultrasound has limited ability to image the calf veins, there is potential for ultrasound studies to classify patients with calf DVT as...

As point-of-care applications of lab testing demand more rapid and clinically integrated order entry and results-reporting processes, it becomes paramount for the laboratory to investigate entire clinical processes. Direct observation and process mapping of these clinical applications – end to end - are "lean" tools...

This is the second of two articles focusing on the reference interval, the most widely used tool for interpretation of patient test results.  The first [1] was an introduction to the theoretical concepts that underpin the significance, construction and use of reference intervals. Here consideration is given to the...

Applications of point-of-care testing (POCT) for diagnostic biomarker measurement in healthcare have increased significantly in recent years in a wide range of clinical scenarios. These include infectious disease, critical care, cardiology and other areas of emergency medicine. Traditionally, routine clinical...

Definite diagnosis of infection requires microbiological documentation; however, the identification of a specific etiology is frequently missing. In addition, bacterial cultures require at least 24-48 hours for a final result, which is too long for a decision to start antibiotics. Currently, the evaluation of the...

The population-based reference interval is the most widely used tool for interpretation of individual patient laboratory test results. The clinical value of those results depend crucially on the reference intervals with which they are compared, and all efforts directed at ensuring analytically precise and accurate...

Updated with new information from a 2008 article! Health demands that despite quite significant variation in its rate of production, the amount of carbon dioxide in blood is maintained within well-defined narrow limits. The homeostatic mechanisms that maintain the normal content of carbon dioxide in blood are...

All clinical procedures and treatments are associated with potential adverse effects of greater or lesser significance.  The undisputed value of blood testing for both diagnosis and monitoring of disease is tempered by the recognition that repeated blood sampling can result in blood loss of sufficient magnitude to...