As a blood marker of tissue hypoxia, lactate is routinely measured to assess and monitor critically ill patients. Hypoperfusion and resulting tissue hypoxia with evolving lactic acidosis is a common feature of many conditions that render patients critically ill. Tissue hypoxia is by no means the only cause of lactic...

Raised plasma/serum potassium (hyperkalemia), which is widely defined as potassium >5.0-5.3 mmol/L, is a common electrolyte disturbance with many possible causes, including renal failure, acidosis, aldosterone deficiency and tissue damage. Severe hyperkalemia is a potentially life-threatening condition that demands...

Plasma calcium is maintained within normal limits by the integrated action of three hormones: parathyroid hormone (PTH); the vitamin D-derived renal hormone, calcitriol; and the thyroid hormone, calcitonin.  Hypocalcemia (reduced blood calcium), which is defined as corrected total plasma calcium <2.20 mmol/L and...

Reduced blood glucose (hypoglycemia) is common during the hours and days following birth. This so-called neonatal hypoglycemia may be transitory and asymptomatic but can result in a range of acute symptoms. If sufficiently prolonged, the condition is associated with risk of irreversible neurological (brain) damage....

Discussion of acid-base physiology usually focuses mainly on the role of lungs and kidneys, and it is a disease that affects the function of these two organs that are usually invoked when considering, in general terms, acid-base disorders. As the authors of this review article make clear, the liver also plays an...

In health plasma potassium concentration is maintained within the approximate reference range of 3.5-5.3 mmol/L in part by the action of the adrenal hormone aldosterone on renal tubule cells. Hypokalemia (reduced blood potassium), defined as plasma potassium <3.5 mmol/L, is one of the most common electrolyte...

Procalcitonin (PCT) is a peptide (116 amino acids) precursor of the calcium-regulating thyroid hormone, calcitonin. Serum/plasma levels are very low (<0.1 ng/mL) or even undetectable in healthy individuals. However, in response to cytokine release during systemic inflammation, PCT synthesis increases in extra-thyroidal ...

As the authors of this review article acknowledge, chronic kidney disease (CKD) is a growing public health burden around the world. Recent study, cited by the authors, suggests an estimated 14 % of the US population are now diagnosed with CKD, and 0.2 % have end-stage renal disease (ESRD), the most severe presentation ...

Acute kidney injury (AKI) is defined as an abrupt decrease in kidney function evidenced by recent (within 48 hours) increase in serum creatinine concentration equal to or greater than 26.5 µmol/L (0.3 mg/dL). It can be a complication of many conditions that warrant hospital admission so it is common; up to 20 % of...

The gold standard sample for blood gas analysis is arterial blood. Compared with collection of venous or capillary blood, collection of arterial blood by arterial puncture is a painful procedure that can induce feelings of anxiety. The notion that this pain and anxiety could be a source of preanalytical error in blood ...