Pulse oximetry provides a simple non-invasive method of monitoring the oxygenation status of patients by indirectly measuring the percentage of hemoglobin that is saturated with oxygen, i.e. % oxygen saturation (SpO₂). Pulse oximetry has important limitations, including inaccurate readings in patients with inherited...

Updated with new information from a 2008 article! Health demands that despite quite significant variation in its rate of production, the amount of carbon dioxide in blood is maintained within well-defined narrow limits. The homeostatic mechanisms that maintain the normal content of carbon dioxide in blood are...

Chest pain is a frequent cause of hospitalization and comprises a significant proportion of the acute medical workload in the western world. This issue is compounded for those living in regional or remote communities due to limited access to pathology services and tertiary-referral institutions. Evidence suggests...

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...

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 ...

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...

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...

01 Copy of Acid base balance