All clinical procedures and treatments are associated with potential adverse effects of greater or lesser significance.  The undisputed value of blood testing for both diagnosis and monitoring of disease is tempered by the recognition that repeated blood sampling can result in blood loss of sufficient magnitude to...

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...

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...

With the use of a new Data Management System (DMS) software program [1], the majority of Point Of Care Testing (POCT) equipment throughout the Waikato District Health Board region has been connected to the Laboratory Information System (LIS) and the Hospital Information System (HIS). Prior to the new DMS, viewing...

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...

Respiratory acidosis and alkalosis are characterized by primary change in pCO₂ (increase in the case of acidosis and decrease in the case of alkalosis). Secondary physiological compensation, aimed at returning blood pH to normal, is evident in blood gas results as a change in bicarbonate concentration (increase in the ...

Transient increase in serum bilirubin concentration is a normal physiological feature of the neonatal period and this rise is sufficient to cause visible jaundice in around 60 % of newborns. For most the condition is harmless and resolves spontaneously with no long-term effects. However for those neonates with...

Critically ill patients often require frequent monitoring of blood gases and the arterial blood required for these analyses is most conveniently sampled via an indwelling arterial catheter; arterial catheterization also provides the means for continuous monitoring of blood pressure.  Of all the invasive procedures...

Umbilical cord blood gas analysis has for many years been recommended for assessment of newborn babies after high-risk delivery associated with possible hypoxic stress and consequent risk of permanent brain damage. More recently there has been an increasing trend towards its routine use after all deliveries.  With...