In health no more than 1-2 % of total hemoglobin is present as methemoglobin. This is a dysfunctional form of hemoglobin that is unable to bind and transport oxygen because the iron atom of the heme moiety is in the ferrous rather then the normal ferric state. Abnormal increase in methemoglobin, a condition called...

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...

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...

Blood gas analysis of umbilical cord blood provides the means for establishing the acid-base status of babies at the time of birth. If there is to be any delay in sampling, the portion of cord from which the sample is to be taken should be double-clamped and thereby isolated from the placenta.  Previous studies have...

Measurement of blood lactate provides clinicians with a valuable means of identifying and monitoring critically ill patients who are suffering clinical shock as a result of severe trauma, sepsis or cardiogenic shock. Lactic acid accumulates in the blood of these patients due to the tissue hypoxia that results from...

Carboxyhemoglobin (COHb) is the product of the reaction between hemoglobin and carbon monoxide, and measurement of COHb is used in the diagnosis of carbon monoxide poisoning. Since carbon monoxide is a common pollutant present in cigarette smoke and car exhaust, it is difficult to be too dogmatic about what...

Reprinted with permission from Elsevier from "Neonate capillary blood gas reference values", by Jocelyne Cousineau, Suzanne Anctil, Ana Carceller, Monique Gonthier and Edgard E. Delvin, CLINICAL BIOCHEMISTRY, Vol no 38, 2005, pp 905-907. Copyright 2005 by Canadian Society of Clinical Chemists. OBJECTIVES Because...

Hemoglobin is the oxygen-carrying protein contained in red blood cells (erythrocytes). Although normally present in only trace amounts, there are three species of hemoglobin that cannot transport oxygen.  The three species, collectively called dyshemoglobins because of their functional redundancy, are methemoglobin,...

Lack of homogeneity of a blood sample can lead to incorrect results. In this paper, the quality requirements of a sample prior to mixing, the type of samples, sample collection devices and tools and mechanics of mixing will be highlighted. Issues related to the mixing of samples intended for hematological and blood...

Iatrogenic phlebotomy loss resulting from the intensive clinical monitoring in the weeks immediately following birth remains the primary cause of neonatal anemia and the need for red-blood-cell (RBC) transfusion. Reducing RBC transfusion needs in the neonatal intensive care unit (NICU) requires new approaches for...