Modern blood gas analyzers often have incorporated sensor technology that allows measurement of plasma lactate concentration. In nature lactate exists in two isoforms: L-lactate and D-lactate.  In all vertebrates, including humans, the L-lactate form is by far the most abundant and pathophysiologically significant,...

Blood gas analysis (BGA) is a laboratory and point-of-care test routinely used to assess acid-base status along with adequacy of ventilation and oxygenation among predominantly critically/acutely ill patients.  The ”gold standard” sample for BGA is arterial blood collected anaerobically by needle puncture of an artery ...

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...

Clinical laboratory measurement of serum/plasma creatinine concentration has been used to assess patient kidney function for well over 50 years.  With the 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...

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.  ...

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...

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...

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...