In health plasma ionized calcium concentration (iCa) is maintained within the approximate reference range of 1.15-1.30 mmol/L (4.6-5.2 mg/dL) principally by the synergistic action of two hormones: parathyroid hormone (PTH) and the vitamin D-derived hormone, calcitriol.  Hypercalcemia (increased blood calcium),...

Monitoring patient acid-base status is one of three principal clinical utilities of blood gas analysis (the other two are monitoring patient oxygen and ventilation status). Three parameters generated during blood gas analysis (pH, pCO₂ and bicarbonate) allow this acid-base assessment and classification of all...

It is widely acknowledged that the majority of errors in clinical laboratory and point-of-care testing occur during the preanalytical phase. Blood collection (phlebotomy) is an element of the preanalytical phase particularly prone to potential error, so that adherence to authoritative (evidence-based) recommendations...

This article demonstrates that adding a lot of patients without disease and with low test results to a study may improve the ROC curve significantly without any improvement in sensitivity or in positive predictive value of the parameter evaluated. The precision-recall curves are not impacted by the addition of...

In health plasma potassium concentration is maintained within the approximate reference range of 3.5-5.2 mmol/L, so that hypokalemia (reduced plasma potassium) is defined as plasma potassium < 3.5 mmol/L.  Mild hypokalemia (plasma potassium in the range of 3.0-3.5 mmol/L) is a common electrolyte disturbance that may or ...

Blood gas analysis involves three measurements: blood pH, partial pressure of carbon dioxide in blood plasma (pCO₂) and partial pressure of oxygen in blood plasma (pO₂). The first two, pH and pCO₂ along with other derived (calculated) parameters (bicarbonate, base excess) generated during blood gas analysis allow...

Nationwide harmonization of clinical laboratory practice is a stated strategic goal of the Croatian Society of Medical Biochemistry and Laboratory Medicine (CSMBLM). In 2013, a CSMBLM working group conducted a nationwide survey of all aspects of blood gas testing practice in Croatian hospital laboratories.  This...

The blood gas analyzer has an established role in the delivery suite of obstetric units. Measurement of umbilical cord blood pH and base excess provides objective evidence of the metabolic condition of newborn babies at the moment of birth.  Specifically, it allows identification of those with significant metabolic...

This article evaluates venous blood as an alternative to arterial blood for lactate measurement, highlighting the general considerations related to each of the three types of venous blood which can be used for lactate measurement: peripheral venous blood, central venous blood and mixed venous blood.

Procalcitonin (PCT) is a biomarker which is elevated in bacterial infection. Usefulness of PCT measurements in community-acquired pneumonia (CAP) has to be proven by many studies. A single measurement of PCT on admission or outpatient visits is useful to diagnose CAP, estimate causative pathogens pattern, and for...