CO-oximetry provides the means for automated spectrophotometric measurement of the concentration of total hemoglobin (ctHb) in blood and the percentages of the four hemoglobin derivatives that total hemoglobin comprises: oxyhemoglobin (O₂Hb); deoxyhemoglobin (HHb); carboxyhemoglobin (COHb); and methemoglobin (MetHb)....

Neonates nearly always experience their single largest day of blood loss on the day of birth due to admission laboratory testing. The term "admission laboratory testing" refers to the initial blood tests done when a baby is born and admitted to the NICU.  Total circulating blood volume in a 3.5 kg term newborn is 280...

Metabolic alkalosis, a disturbance of acid-base homeostasis, with many possible causes, is characterized by a primary increase in blood pH and bicarbonate (HCO₃). Hypoventilation is the compensatory respiratory response to metabolic alkalosis that results in increased pCO₂. The often complex nature of the etiology of...

Whilst arterial blood gas analysis is the gold standard method for determination of arterial oxygen saturation (sO₂(a)), pulse oximetry provides an alternative, more convenient method that does not depend on sampling arterial blood.  Because of its ease of operation and ability to monitor oxygen saturation in real...

Arterial blood is the “gold standard” sample for blood gas analysis. Compared with venous blood sampling, arterial blood sampling is technically more difficult as well as being more painful and hazardous to the patient. These are among the considerations that drive the continuing research interest in establishing...

Each issue of the journal Emergency Clinics of North America is devoted to the review of a single topic of relevance to emergency medical care. The topic for the February 2014 issue was clinical toxicology and one of the 11 review articles in this issue, written by an emergency care doctor with specialist interest in...

Ensuring that tissues are adequately oxygenated, with the help of supplemental oxygen where necessary, is a prime objective of critical/acute medical care. By measurement of the amount of oxygen dissolved in blood (pO₂(a)) and that bound to hemoglobin (sO₂(a)), arterial blood gas analysis provides the most accurate...

Ensuring adequate oxygen delivery to tissues is a prime objective of acute/critical medical care. There is no routinely available method for directly monitoring tissue oxygenation; instead clinicians must depend on available indirect measures. Although not the only factor to be considered, measurement of the amount of ...

The use of natriuretic peptides like B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) has increased during the last decade and so has the medical evidence of their utility. This article highlights natriuretic peptide synthesis and release. Based on essential clinical trials the article gives medical...

Reprinted from Ann Lab Med 2013 Sep; 33(5):309-18. Christenson E, Christenson RH: "The role of cardiac biomarkers in the diagnosis and management of patients presenting with suspected acute coronary syndrome". Myocardial infarction (MI) is the leading cause of death in the developed world. Biomarkers have an...