Blood gas analysis has been performed at the point of care for well over 20 years and is sufficiently established for clinicians to have no misgivings about using pH, pCO₂ and pO₂ results obtained at the point of care for direct patient management.  Modern blood gas analyzers now have the capacity to measure not only...

The notion that orange juice may be harmful to health seems counterintuitive if not bizarre, but as a recently published case history reveals, orange juice contains significant amounts of potassium and ingestion of large quantities of orange juice can lead to hyperkalemia of sufficient severity to threaten life.  Over ...

Umbilical cord blood gas analysis provides objective evidence of neonatal condition at birth; a particular utility of the test is to identify those babies who have suffered significant oxygen deficit prior to delivery. Traditional obstetric practice is to clamp the umbilical cord within seconds of delivery but some...

Despite significant developments in neonatal medicine over the past decade or two there has been no overall reduction in the number of neonatal deaths according to the results of a recently published US study.  Researchers at the University of Colorado in Denver performed a retrospective study of all 779,385 live...

Arterial oxygen saturation sO₂(a) is a parameter calculated during blood gas analysis that is useful for monitoring respiratory function. Pulse oximetry provides a safer and more convenient, non-invasive means of measuring oxygen saturation that is used in many clinical settings.  The value of pulse oximetry depends...

Intensive intravenous insulin therapy directed at maintaining blood glucose concentration within tight normal limits (4.4–6.1 mmol/L) is now a standard of care for the critically ill. This requires frequent point of care blood glucose testing.   For appropriate intravenous insulin dosing it is vital that the chosen...

Measurement of plasma CRP might be helpful in deciding if patients recovering from critical illness can be safely discharged from the intensive care unit (ICU) to other wards, according to the results of a recently published study conducted at the ICU of the Royal Perth Hospital in Australia. A significant minority of ...

Two very different reviews of acid-base pathophysiology are recently published. The first, written by a nurse educator is a comprehensive overview and serves as an introduction to the topic. The approach is familiar and reflects standard physiology texts.  After a very brief synthesis of the significance of...

In health the partial pressure of oxygen (pO₂) in arterial blood is maintained between 10.6 and 13.3 kPa (80-100 mmHg). Hypoxemia (reduced arterial pO₂) is usually a signal of significant respiratory or cardiac disease and respiratory failure is defined as arterial blood pO₂ < 8 kPa ( So when arterial blood gas...

In the USA it is permissible to store donated blood for transfusion for up to 42 days. Although this is helpful in matching supply with demand for blood products, red cells undergo a number of changes in storage that affect their function.  There is conflicting evidence to suggest that the structural and functional...