Although measurement of serum lactate has an established role in the monitoring of critically ill patients at many hospitals around the world, the practice is by no means universal, reflecting a controversy that still surrounds the topic. In short there remains no consensual answer to the broad question: Should we...

Diabetic ketoacidosis (DKA) is a life-threatening acute metabolic disturbance that results from absolute or relative insulin deficiency. It is usually precipitated by intercurrent illness and is a relatively common complication of type 1 diabetes but only rarely occurs in those suffering type 2 diabetes.  The cardinal ...

No history of the development of blood gas analysis and its application in clinical and physiology research would be complete without consideration of the pioneering work of anesthesiologist researcher Dr John Severinghaus.  As a young research fellow in the 1950s he developed the Stow-Severinghaus-type carbon dioxide ...

Traditionally, interpretation of blood gas results for the assessment of acid-base status has been based on the Henderson-Hasselbalch equation, the central focus of which is the carbon dioxide – the bicarbonate buffer system. At its most reduced form the equation can be stated as “pH is proportional to the ratio of...

As a global marker of tissue oxygenation serum lactate measurement has proven its usefulness in monitoring the critically ill. It has also proved useful as a screening tool for sepsis in the emergency room.  However, lactate measurement is not always readily available. Increased lactate is a common cause of raised...

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...

The field of point-of-care testing (POCT) is entering a period of rapid expansion. This expansion is being driven by new evidence for clinical effectiveness of POCT, and new technologies that allow consolidation of testing onto smaller platforms. Technological improvements will also lead to increased accuracy for...

The notion that increased oxygen delivery limits ischemic damage to the myocardium during myocardial infarction seems, on the face of it, highly plausible. Perhaps not surprising, then, that for the best part of a century administration of oxygen has been a routine component of medical care for many patients suffering ...

The lowest ever recorded arterial oxygen tension (pO₂) was just one result of a series of remarkable physiological investigations conducted on Mount Everest that included arterial blood gas analysis at an altitude of 8,400 m (27,599 ft) above sea level, just 484 m short of the summit.  At this high altitude the...