Anemia is a common feature of critical illness and roughly a third of all patients being cared for in intensive care units are given red-cell transfusion. Although such transfusions are unequivocally lifesaving for some patients, e.g. the exsanguinating trauma victim, the benefit is less clear-cut for others.  There...

Few studies have addressed the predictive value of C-reactive protein at different cutoff values in appendicitis. We have determined the cutoff values for C-reactive protein levels at different periods during clinical evolution of appendicitis and established their use to support the diagnosis of appendicitis. The...

Point of care (POC) testing has become an important part of nephrological care. In cases of acute renal failure, POC is indispensable in deciding the need for dialysis, but is also essential in the management of patients on regular dialysis. For example, hyperhydration, cardiovascular adverse events and inflammation...

Arterial blood gases (ABG), a clinical test that involves measurement of the pH of arterial blood and the amount of oxygen and carbon dioxide dissolved in arterial blood, is routinely used in the diagnosis and monitoring of predominantly critically/acutely ill patients being cared for in hospital emergency rooms and...

Pulse oximeters, which are ubiquitous in nearly all areas of clinical care, provide the means for safe, non-invasive continuous monitoring of blood oxygen saturation. The validity of using pulse oximetry to assess patient blood oxygenation status depends on SpO₂, the parameter measured by pulse oximetry, being a...

The incorporation of CO-oximeters in modern blood gas analyzers allows rapid determination of the amount of carboxyhemoglobin in blood. This, in turn, allows rapid diagnosis of carbon monoxide poisoning, the subject of a recently published review.  This wide-ranging review article begins with consideration of the...

Arterial blood gas analysis in cases of metabolic acidosis reveals primary decrease in pH and bicarbonate, and secondary (compensatory) reduction in pCO₂. The most common cause of metabolic acidosis is increased production of endogenous metabolic acids, either lactic acid, in which case the condition is called lactic...

Extracellular (serum) potassium concentration is normally maintained within the approximate reference range of 3.5-5.2 mmol/L; this is important for normal cardiac function. Both reduced serum potassium (hypokalemia) and increased serum potassium (hyperkalemia) can, if sufficiently severe, be associated with...

The calcium present in blood plasma comprises two almost equal fractions: half is bound to albumin and the remainder is unbound, free ionized calcium. Only the free ionized calcium is physiologically active. There are two ways of assessing patient blood calcium status.  The first – at one time the only available...

Many authors contend that drawing of umbilical ABGs is a simple method to evaluate the condition of the neonate and ideally would be routinely done for all newborns [13]. Other authors disagree. Appropriate general principles guide clinicians when drawing and interpreting ABGs for all patients. The special needs of...