title: Colloid osmotic pressure of plasma replacement fluids.
abstract: Colloid osmotic pressure (COP) of some of the most frequently used plasma replacement fluids was measured with a colloid osmometer. COP of 4% human albumin solutions was only half that of normal human serum (13.6 +/- 0.6 vs. 27.5 +/- 2.7 mmHg (1.8 +/- 0.1 vs. 3.7 +/- 0.4 kPa)) (mean +/- s.d.), whereas COP of 20% human albumin solutions was eight times higher (196.0 +/- 12.3 mmHg (26.1 +/- 1.6 kPa)). Enhancing the protein concentration from 4% to 20% in the human albumin solutions increased COP 14-fold, reflecting the exponential relationship between protein concentration and COP of a solution. Fresh donor plasma furnished by the hospital blood-bank had a COP about 30% below normal human serum (18.1 +/- 1.3 mmHg (2.4 +/- 0.2 kPa)), due to dilution during preparation. Dextran 70 (6%) had a COP more than twice, and Ringer-Dextran 60 (3%) about 75% of that of normal human serum. Dextran 40 (10%) and gelatin (3.5%, Haemaccel) leaked markedly through the membrane of the colloid osmometer, making acceptable measurements impossible. Seven different hydroxyethyl starch (HES) solutions were measured, and the COP varied between half and 3 times that of normal human serum, depending on molecular weight and concentration of the HES.
authors.affiliation: Norwegian Army Medical Training Center, Lahaugmoen.
authors.forename: T
authors.initials: T
authors.lastname: Tønnessen
authors.forename: S
authors.initials: S
authors.lastname: Tølløfsrud
authors.forename: U E
authors.initials: UE
authors.lastname: Kongsgaard
authors.forename: H
authors.initials: H
authors.lastname: Noddeland
mesh_terms: D003102:Colloids / Q000737:chemistry; D003911:Dextrans / Q000737:chemistry; D005260:Female; D005612:Freeze Drying; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000737:chemistry; D008297:Male; D008567:Membranes, Artificial; D009997:Osmotic Pressure; D010949:Plasma / Q000737:chemistry / Q000502:physiology; D010952:Plasma Substitutes / Q000737:chemistry*; D011097:Polygeline / Q000737:chemistry; D012709:Serum Albumin / Q000737:chemistry; D014462:Ultrafiltration / Q000295:instrumentation
chemical_list: D003102:Colloids; D003911:Dextrans; D006895:Hydroxyethyl Starch Derivatives; D008567:Membranes, Artificial; D010952:Plasma Substitutes; D012709:Serum Albumin; D011097:Polygeline