Anemia, which is defined as hemoglobin (Hb) concentration The kidneys are essential to the regulation of red-cell production and thereby maintenance of normal Hb concentration because the hormone erythropoietin, which regulates red-cell production, is synthesized in the kidneys. The usually normochromic, normocytic...

Hemodialysis and related treatments for those with failing kidneys all involve blood flow through a circuit outside the body. This extracorporeal circuit - the dialysis machine and its connections from and back to the body - is a non-physiological, pro-coagulant environment.  To counter the tendency for patients'...

The process of patient sample testing, whether performed in the clinical laboratory or at the point of care, is the sum of three distinct phases. The first is the preanalytical phase, which includes test selection as well as sample collection and handling.  The second is the analytical or measuring phase that...

Over the years, as clinicians have learned how to utilize it, permissive hypercapnia has been finding a place in healthcare. However, it is important to bear in mind that numbers do not tell the entire story. It is imperative to understand the entire clinical picture before you act. For example, an acidic pH of 7.21...

Clinical laboratory measurement of serum/plasma creatinine concentration has been used to assess patient kidney function for well over 50 years. With incorporation of creatinine analyses to blood gas and other point-of-care platforms the test is now available outside the laboratory, at the bedside and in the clinic.  ...

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 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...

The integrity and function of all cells depend on an adequate supply of oxygen. Severe acute illness is frequently associated with inadequate tissue perfusion and/or reduced amount of oxygen in blood (hypoxemia) leading to tissue hypoxia.  If not reversed, tissue hypoxia can rapidly progress to multiorgan failure and ...

Homeostatic mechanisms ensure that in health the extracellular fluid (ECF) concentration of electrolytes, including calcium, is maintained within well-defined limits. Abnormality in ECF calcium concentration can have profound adverse effects.  The most common means of assessing calcium status is to measure total...

Measurement of plasma/serum sodium concentration is one of the most frequently requested blood tests in clinical practice. Although usually performed in the laboratory, the test is also available at the point of care using technology incorporated into blood gas and other point-of-care analyzers. In health, sodium...