Arterial blood is the standard sample for measurement of pH, pCO₂ and pO₂, but collection of arterial blood can be painful. Furthermore, it is a procedure associated with some risk to the patient and can therefore only be performed by trained, medically qualified staff.   Capillary blood collection by finger or...

Acid-base physiology and significance of blood gas results are topics that many students find daunting. Their difficulty is not aided by the non-standard abbreviations used to indicate partial pressure of a gas. The issue is highlighted in a recent letter to the journal Clinical Chemistry.  The authors cite the...

Where do you go for help, when you are a parent of a child who stops breathing while it sleeps? If you live in the south of Sweden, you go to Halmstad County Hospital, where a team of specialists are ready to monitor your sleeping child by polysomnography (PSG). The neonatal intensive care unit (NICU) in Halmstad has ...

Hypoxia and hypoxemia describe states of oxygen deficiency: hypoxia is deficiency in oxygenation at tissue or cellular level whilst hypoxemia is a suboptimal normal partial pressure of oxygen. Hypoxia and hypoxemia are interrelated, as untreated hypoxemia will ultimately result in hypoxia.  It should also be noted...

Hemorrhage, due to a reduction in the coaguability of blood, is a common cause of morbidity and mortality among trauma victims and the critically ill in general. Reduced blood pH (acidosis) is also common in these patient groups. Previous studies have shown that acidosis is an independent risk factor for development...

Measurements of pH, pCO₂ and pO₂ of arterial blood during blood gas analysis are all made at normal body temperature, 37 °C. The sample is warmed to that temperature prior to analysis. Blood gas analyzers provide the option for these primary measurements to be automatically "corrected" to the patient’s actual body...

Conventionally, arterial blood is sampled for blood gas analysis, but if the purpose is to assess acid-base balance, venous blood may be an acceptable alternative. That is the main conclusion of a recently published study conducted at the intensive care units of two Melbourne hospitals.  The objective of the study was ...

Pulse oximetry provides the means for continuous non-invasive monitoring of oxygen saturation (SpO₂). Although not currently used for the purpose, recent international guidelines suggest that pulse oximetry may be useful in the assessment of newborns who require urgent resuscitative measures at the time of birth....

The principal function of the protein hemoglobin contained in red blood cells is transport of oxygen in inspired air from lungs to tissue cells. Although normally present in only trace amounts, there are three species of hemoglobin that cannot transport oxygen. The three species, collectively called the dyshemoglobins ...

Hospital do Coração (HCor) in São Paolo, Brazil is a hospital for cardiac patients, many of whom are children and newborns. Cardiac patients are closely monitored with respect to acid base and blood gases, and even the newborns have several arterial and venous blood samples drawn daily. Dr Alberto Duarte from the...