Pulse oximetry provides the means for continuous non-invasive monitoring of blood oxygenation by measuring % oxygen saturation (SpO₂). This safe, easy and convenient method of monitoring oxygenation status is ubiquitous in clinical medicine and is now a routine part of the overall assessment and monitoring of all...

Many drugs, when taken in overdose, can deleteriously affect acid-base balance, leading to abnormal arterial blood gas (ABG) results. Aspirin is one such, and perhaps because of its easy availability, one of the most common of all drugs to be taken in overdose. Salicylate (aspirin) poisoning thus represents the most...

Most babies born prematurely have respiratory problems and require assisted ventilation and oxygen therapy to ensure adequate tissue oxygenation. Supplemental oxygen is a double-edged sword for these babies because although of life-preserving benefit, oxygen in excess is toxic.  The principal (but not the only)...

Metformin, a blood-glucose-lowering drug widely used for treatment of type 2 diabetes, is associated with risk of potentially fatal metabolic (lactic) acidosis. This can occur not only following overdose but also at therapeutic dose in patients with pre-existing renal or liver disease. Results of arterial blood gas...

If the results of a recent New Zealand study are representative, there is room for improvement in the quality of blood gas test result interpretation among emergency-room medical staff. A total of 80 emergency-room doctors (37 consultants and 43 emergency-medicine trainees) voluntarily submitted themselves for a...

Over the years, as clinicians have learned how to utilize it, permissive hypercapnia has been finding a place in healthcare. However, it is important to bear in mind that numbers do not tell the entire story. It is imperative to understand the entire clinical picture before you act. For example, an acidic pH of 7.21...

Metabolic acidosis, the most common disturbance of acid-base balance among the critically ill, is characterized by arterial blood gas results that reveal primary decrease in bicarbonate and compensatory decrease in pCO₂(a). Blood pH is reduced unless respiratory compensation is complete. It is most often the result of ...

The prognostic value of measuring umbilical cord blood pH at birth is examined in a recent meta-analysis study. Cord blood acidosis (usually defined as cord blood pH <7.0) is considered evidence that the newborn baby was deprived of oxygen during labor, and in some maternity units cord blood pH is used in the...

Arterial blood gas analysis includes measurement of partial pressure of oxygen (pO₂(a)) and calculation of oxygen saturation (sO₂(a)), both useful for assessing patient oxygenation status. Hypoxemia is diagnosed if pO₂(a) is below the lower limit of the reference range (10.6 kPa, 88 mmHg). Pseudo-hypoxemia is...

BACKGROUND: Besides actual pH, base excess (ctH⁺_B (mmol/L)) is of major importance since it is meant to reflect lactate acidosis due to fetal hypoxia; in vivo BE_B is not independent from pCO₂. Independence is achieved by using the extended extracellular fluid (Ecf) for dilution of hemoglobin (cHb_B), reducing cHb_B to ...