In health serum potassium concentration is maintained within the approximate reference range of 3.5-5.2 mmol/L (or 3.5-5.2 mEq/L). Hypokalemia (reduced serum potassium) is therefore defined as serum potassium <3.5 mmol/L (or <3.5 mEq/L). Severe hypokalemia (<3.0 mmol/L) is associated with muscular weakness progressing to ...

Umbilical-cord blood gas analysis provides objective evidence of the metabolic status of neonates at the time of delivery. Perinatal metabolic acidosis is indicative of hypoxia (sometimes the result of asphyxia during birth) and associated risk of permanent brain damage.  A recently published study sought to assess...

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)....

The management at the emergency department of patients presenting with symptoms of chest pain and/or acute dyspnea accounts for a substantial proportion of emergency care resources. In the work-up of these patients the blood measurements of cardiac troponins and brain natriuretic peptides are recommended by current...

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...

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 ...

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...

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...

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...

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...