Premature neonates frequently have inadequate respiratory function and require oxygen therapy during the weeks after birth. Since they are also exquisitely vulnerable to oxygen toxicity, careful monitoring of oxygen status is an essential component of neonatal intensive care.  Measuring % oxygen saturation by pulse...

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...

 Of all tests performed on patient blood samples, arterial blood gases (ABGs) are conceptually probably the most complex. An understanding of the clinical significance of the measured and derived parameters generated by blood gas machines depends on a basic knowledge of so many topics, including acid-base theory,...

Hemolysis, the breakdown of erythrocyte (red-cell) membranes, can occur in vivo as a result of disease, or more commonly in vitro when it is most usually a consequence of poor blood collection or sample handling technique.  Hemolysis is of significance for laboratory staff because it results in the release of...

The population-based reference interval is the most widely used tool for interpretation of individual patient laboratory test results. The clinical value of those results depend crucially on the reference intervals with which they are compared, and all efforts directed at ensuring analytically precise and accurate...

All newborn babies have, by comparison with adults, a raised serum concentration of unconjugated (and therefore total) bilirubin, due principally to the transient increase in red cell destruction associated with the move from intrauterine support to physiological independence.  In close to half of all newborns the...

Metabolic acidosis is the most common disturbance of acid-base balance among the critically ill of all ages, usually due to increased lactate production consequent on inadequate tissue perfusion and/or hypoxemia. The condition is characterized by primary reduction in bicarbonate and pH revealed during arterial blood...

The factors that influence critical care nursing staff when making the decision to sample blood for arterial blood gas analysis is the subject of a recent UK study. The authors of this study specifically sought to establish if there is an association between patient values for four parameters (FO₂(I) , pCO₂, pO₂ and % ...

Over a third of patients admitted to intensive care develop hypernatremia (raised serum sodium concentration) or hyponatremia (reduced plasma sodium concentration) within a few days of admission. Both hypo- and hypernatremia acquired after admission prolong hospital stay and decrease chance of survival.  These are the ...