Arterial blood is the standard sample for blood gas analysis but arterial blood sampling is more painful and hazardous to the patient. Such is the relative convenience and safety of sampling venous blood that several studies have sought to investigate the validity of its use as a substitute for arterial blood.  The...

Increased serum bilirubin (hyperbilirubinemia) and consequent jaundice are common during the neonatal period. Around 50 % of newborns develop some degree of jaundice, during the first week of life, but for the vast majority this is mild (serum bilirubin peaking no higher than 150-200 µmol/L) and spontaneously resolves ...

Hospitalized patients are frequently prescribed parenteral fluids and in most instances these are hypotonic (e.g. 0.18 % NaCl in 5 % dextrose). Controversy surrounds the routine use of hypotonic parenteral fluids because they can cause hyponatremia (reduced plasma sodium concentration), which if sufficiently severe...

The critical significance of the preanalytical phase of blood testing is highlighted by the tragically fatal case of an intensive-care patient who was given an inappropriately high dose of insulin following a falsely high blood glucose result. The patient was recovering from multiple organ failure following surgery in ...

Plasma sodium and chloride concentration are routinely measured using either a direct or indirect ion-specific electrode (ISE). Direct ISE is the technique employed in blood gas and most other point-of-care analyzers whereas indirect ISE is used in the majority of biochemistry profiling analyzers sited in central...

Despite the fact that self-monitoring of blood glucose (SMBG) apparently accounts for an amazing 20 % of the expenses of the total in vitro diagnostic market worldwide (27 % in the US), there remains a woeful lack of evidence that SMBG is actually effective in improving the clinical outcome of diabetic patients.  In...

Results of hemoglobin (Hb) and hematocrit (Hct) measurement are routinely used to assess blood loss among trauma patients. But is it necessary to measure both parameters and if not, is one more reliable than the other? There is evidence to suggest that many physicians believe hematocrit is a more sensitive indicator...

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...

Accurate blood gas results depend on a homogeneous blood sample and the necessity for thorough mixing of samples is reflected in written standard operating procedures for blood gas analysis. The results of a recent study suggest, however, that manual mixing techniques routinely used may be inadequate in achieving a...

Modern blood gas analyzers often have incorporated technology that allows hemoglobin measurement on the same blood sample used to measure pH, pCO₂ and pO₂. Clinicians working in a UK neonatal intensive care department where such an instrument was routinely used for blood gases were keen to exploit the newly available...