Some of the frequently asked questions are: Should we use BE (base excess) or SID (strong ion difference) as a measure of a metabolic acid-base disturbance?  Is there any difference between BB (buffer base) and SID? Should we use SBE (standard base excess), i.e. BE referring to the expanded extracellular fluid or...

BACKGROUND: Besides actual pH, base excess (ctH⁺_B (mmol/L)) is of major importance since it is meant to reflect lactate acidosis due to fetal hypoxia; in vivo BE_B is not independent from pCO₂. Independence is achieved by using the extended extracellular fluid (Ecf) for dilution of hemoglobin (cHb_B), reducing cHb_B to ...

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...

In recent years there has been increasing interest in the significance of the transitory raised blood glucose (hyperglycemia) that very often occurs in individuals suffering critical illness and trauma. A number of studies have shown an association between hyperglycemia and poor outcome. Knowledge in this area is...

The field of point-of-care testing (POCT) is entering a period of rapid expansion. This expansion is being driven by new evidence for clinical effectiveness of POCT, and new technologies that allow consolidation of testing onto smaller platforms. Technological improvements will also lead to increased accuracy for...

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...

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...

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...

Pulse oximetry provides a simple non-invasive method of monitoring the oxygenation status of patients by indirectly measuring the percentage of hemoglobin that is saturated with oxygen, i.e. % oxygen saturation (SpO₂). Pulse oximetry has important limitations, including inaccurate readings in patients with inherited...

There are few medical diagnoses that depend solely on the result of a single blood test, but diabetes mellitus, which is defined by concentration of circulating glucose, is one that does. Quite apart from its long established role in diagnosis as well as life-long monitoring of diabetes, measurement of circulating...