Biomaterial Database

Continuous measurements by impedance of haematocrit and plasma volume variations during dialysis. 1997

M Maasrani, and M Y Jaffrin, and B Boudailliez

URA CNRS 858, Technological University of Compiegne, France.

A technique for continuous measurements of haematocrit and plasma volume in the arterial line of dialysed patients has been tested in vitro and in vivo. This method uses impedance measurements at 5 kHz and requires a single haematocrit measurement. It relies on two assumptions: that plasma resistivity does not change during dialysis and that blood resistivity obeys Hanai's model. Both assumptions are verified during in vitro tests. Haematocrits measured in vivo by this method are found to be in good agreement with direct measurements from blood samples. The haematocrit variation is then used to monitor changes in plasma volume, assuming conservation of erythrocyte volume. In addition, it is possible to obtain the variation in interstitial volume by combining these data with body impedance measurements.

UI	MeSH Term	Description	Entries
D010953	Plasma Volume	Volume of PLASMA in the circulation. It is usually measured by INDICATOR DILUTION TECHNIQUES.	Blood Plasma Volume,Blood Plasma Volumes,Plasma Volumes,Volume, Blood Plasma,Volume, Plasma,Volumes, Blood Plasma,Volumes, Plasma
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D006400	Hematocrit	The volume of packed RED BLOOD CELLS in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, ANEMIA shows a low value; POLYCYTHEMIA, a high value.	Erythrocyte Volume, Packed,Packed Red-Cell Volume,Erythrocyte Volumes, Packed,Hematocrits,Packed Erythrocyte Volume,Packed Erythrocyte Volumes,Packed Red Cell Volume,Packed Red-Cell Volumes,Red-Cell Volume, Packed,Red-Cell Volumes, Packed,Volume, Packed Erythrocyte,Volume, Packed Red-Cell,Volumes, Packed Erythrocyte,Volumes, Packed Red-Cell
D006435	Renal Dialysis	Therapy for the insufficient cleansing of the BLOOD by the kidneys based on dialysis and including hemodialysis, PERITONEAL DIALYSIS, and HEMODIAFILTRATION.	Dialysis, Extracorporeal,Dialysis, Renal,Extracorporeal Dialysis,Hemodialysis,Dialyses, Extracorporeal,Dialyses, Renal,Extracorporeal Dialyses,Hemodialyses,Renal Dialyses
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000293	Adolescent	A person 13 to 18 years of age.	Adolescence,Youth,Adolescents,Adolescents, Female,Adolescents, Male,Teenagers,Teens,Adolescent, Female,Adolescent, Male,Female Adolescent,Female Adolescents,Male Adolescent,Male Adolescents,Teen,Teenager,Youths
D000368	Aged	A person 65 years of age or older. For a person older than 79 years, AGED, 80 AND OVER is available.	Elderly
D000369	Aged, 80 and over	Persons 80 years of age and older.	Oldest Old
D017097	Electric Impedance	The resistance to the flow of either alternating or direct electrical current.	Bioelectrical Impedance,Electric Resistance,Impedance,Ohmic Resistance,Biolectric Impedance,Electrical Impedance,Electrical Resistance,Impedance, Bioelectrical,Impedance, Biolectric,Impedance, Electric,Impedance, Electrical,Ohmic Resistances,Resistance, Electric,Resistance, Electrical,Resistance, Ohmic,Resistances, Ohmic