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...

Bacterial infections are one of the major reasons for patients presenting to the ED - and the main cause of death in elderly patients. It is important to identify elderly patients with bacterial infections early and initiate treatment in the ED for a better outcome. However, an infection in an elderly patient can be...

This second of two articles on understanding the clinical value of measuring urea concentration explores the clinical value of simultaneous measurement of urea and creatinine and calculating the urea:creatinine ratio. The article discusses the causes of increased and decreased ratio as well as the clinical application ...

This first of two articles on understanding the clinical value of measuring urea concentration dives into the physiological topics, such as urea production and renal processing of urea as well as the causes of increased and reduced urea concentration. Kidney disease is associated with reduced urea excretion and...

The measurement of the parameters pH, pCO₂ and pO₂ is vulnerable to a number of preanalytical errors and this article shares practical tips to help avoid these errors, ensuring that the results of analysis accurately reflect the patient’s acid-base and oxygenation status. The tips include the removal of air bubbles, ...

Point-of-care testing (POCT) covers a broad range of pathology and non-pathology testing. The volume of POCT is rapidly increasing with an annual growth rate of 12-15 %. By virtue of its compactness, portability, and the feasibility of operation by non-laboratory personnel, where fast and accurate testing methods and...

The process of blood gas and pH measurement involves preheating the arterial blood sample to normal body temperature (37 °C) prior to measurement of pH, partial pressure of oxygen (pO₂) and partial pressure of carbon dioxide (pCO₂). This ensures that results reflect in vivo temperature condition. A minority of...

The significance of good practice during the preanalytical phase of clinical laboratory investigation cannot be overemphasized. One aspect of the preanalytical phase – the transport of samples – is considered here; in particular the transport of samples via pneumatic tube systems. This is an update of a previous...

Clinical sensitivity, clinical specificity and predictive values are frequently used as performance measure for a biochemistry assay. When D-dimer assay performance is presented, emphasis is often on the negative predictive value (NPV). However, predictive values are greatly influenced by the prevalence of the...