Tight glycemic control (TGC) in the intensive care unit is essential to comprehensive clinical management.  However, TGC that is too aggressive in the wrong patient populations (particularly non-diabetics) can result in hypoglycemia, which brings with it a set of sequelae that can increase morbidity and mortality....

In about 30-40 % of ischemic strokes, even after an extensive clinical investigation, it is not possible to determine any one etiology. It is possible that a fraction of these strokes, named cryptogenic, happen after an episode of paroxystic atrial fibrillation (AF) that was not registered. Strokes due to atrial...

Analytical methods are often developed at one site and transferred to other sites for routine use. Increasingly, the method development is made by manufacturers of instruments and reagents. Regulatory agencies have ruled that the responsibility for the performance of IVDs in the laboratories mainly should lie with...

One of the principal utilities of arterial blood gas (ABG) analysis is to help assess blood oxygenation status. The two ABG parameters used for this assessment are pO₂(a) (partial pressure of oxygen in arterial blood) and sO₂(a) (% of total hemoglobin that is saturated with oxygen). In health pO₂(a) is maintained...

Critical values are those associated with imminent danger unless acted upon promptly. Critical value menus often include results that do not fit this definition, leading to highly variable practice in adult and pediatric laboratories. Existing menus may be subdivided into more uniform tiers of severity: the highly...

Sensitivity and specificity define the discriminative power of a diagnostic procedure, whereas predictive values relate to the predictive ability of a test to identify disease or its absence in individuals.  Predictive values are greatly influenced by the prevalence of the disease and should not be generalized beyond ...

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...

The discriminative ability of a diagnostic procedure is called diagnostic accuracy, and a number of quantitative measures out of which sensitivity and specificity are mostly used in the biomedical literature can express it. Each diagnostic-accuracy measure relates to some specific aspects of a diagnostic procedure....

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...