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...

Practically all victims of significant trauma will have blood sampled for plasma potassium estimation soon after admission to hospital emergency departments. But what is the frequency and significance of abnormal potassium results at admission for these trauma patients?  That was the question addressed in design of a...

Cirrhosis of the liver is associated with increased respiration (hyperventilation) and consequent hypocapnic respiratory alkalosis. The severity of this acid-base disturbance correlates with severity of cirrhosis as well as severity of the abnormal hyperdynamic systemic circulation that characterizes this irreversible ...

In health serum total calcium concentration is maintained within the approximate reference range of 2.15-2.60 mmol/L largely by the synergistic action of two hormones: parathyroid hormone (PTH) and the vitamin-D-derived hormone, calcitriol. These two hormones control absorption of dietary calcium from the gut, renal...

It is rare indeed for change in medical practice to be based on the evidence of a single clinical study. But that is exactly what happened in 2001 following publication of a study conducted at the intensive care unit of a hospital in Leuven, Belgium.  Results of the now celebrated Leuven study indicated that...

In health plasma sodium concentration is maintained within the approximate reference range, 135-145 mmol/L (mEq/L). Hyponatremia (defined as plasma sodium The vast majority of affected patients have mild to moderate hyponatremia (plasma sodium in the range of 120-134 mmol/L), which is usually asymptomatic, especially ...

Health demands that the pH of blood is maintained within a narrow range (7.35-7.45). Monitoring this physiological imperative and detection of so-called acid-base disturbance, in which blood pH is either increased or decreased, is one of the principal clinical utilities of blood gas analysis.  Metabolic acidosis – one ...

Blood gas analyzers often have an incorporated CO-oximeter that allows accurate determination of carboxyhemoglobin (COHb) and methemoglobin (MetHb) from the arterial blood sample submitted for routine blood gas analysis. For patients with suspected acute pulmonary embolism (PE), arterial blood gas analysis is often...

As the authors of a recent wide-ranging review of the subject make clear, point-of-care testing (POCT) has greatly expanded, in terms of both prevalence and functionality, over past decades. They report a predicted average growth rate in the use of POCT in the US of >15 % over the coming years.  The three authors (one ...