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...

This first of two articles on method comparison studies gives some key concepts related to the design of the method comparison study, data analysis and graphical presentation, stressing the importance of a well-designed and carefully planned experiment using adequate statistical procedures for data analysis when...

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, ...

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...

Plasma sodium concentration is measured with an ion-specific electrode (ISE) using either an undiluted sample (direct ISE) or diluted sample (indirect ISE).  This is the second of two linked articles highlighting the spurious sodium values that can occur if an indirect ISE method is used to analyze plasma samples with ...

Reprinted from Ann Lab Med 2014 Sep; 34(4):263-73. Procalcitonin (PCT) is used as a biomarker for the diagnosis of sepsis, severe sepsis and septic shock. At the same time, PCT has also been used to guide antibiotic therapy. This review outlines the main indications for PCT measurement and points out possible...

Disturbance of sodium balance is a common occurrence among hospitalized patients that can, if not identified and treated, cause significant morbidity; severe disturbance is potentially lethal. So estimation of plasma sodium concentration is one of the most frequently requested blood tests.  Historically, plasma sodium ...