title: Trapped plasma vs. osmolality in canine microcapillary hematocrits.
abstract: The trapped plasma in the packed red cell portion of the microcapillary hematocrit of hypertonic canine blood was measured with I-125 labelled albumin. Blood osmolalities were raised by the addition of sodium chloride and meglumine/sodium diatrizoate. The trapped plasma was 1.12 +/- 0.15%, 1.75 +/- 0.27% and 1.77 +/- 0.22% at 300, 580, and 723 mOsm/kg, respectively, for sodium chloride solutions. At 924 mOsm/kg some of the blood plus sodium chloride samples hemolyzed. In the group without hemolysis the trapped plasma was 5.84 +/- 1.35% while in the group with hemolysis it measured 12.43 +/- 1.90%. The trapped plasma with diatrizoate solutions was 1.41 +/- 0.11, 2.15 +/- 0.18 and 5.32 +/- 0.56 at 458, 531 and 602 mOsm/kg, respectively. Above an osmolality of 458 mOsm/kg the trapped plasma was significantly greater for the diatrizoate solutions than for the sodium chloride solutions. At osmolalities below 458 mOsm/kg only a small correction is needed for trapped plasma with either sodium chloride or meglumine/sodium diatrizoate solutions.
mesh_terms: D000818:Animals; D003974:Diatrizoate Meglumine; D004285:Dogs; D004912:Erythrocytes / Q000032:analysis; D005069:Evaluation Studies as Topic; D006400:Hematocrit / Q000379:methods*; D007552:Isotonic Solutions; D009994:Osmolar Concentration; D010949:Plasma / Q000032:analysis*; D012462:Saline Solution, Hypertonic; D012711:Serum Albumin, Radio-Iodinated
chemical_list: D007552:Isotonic Solutions; D012462:Saline Solution, Hypertonic; D012711:Serum Albumin, Radio-Iodinated; D003974:Diatrizoate Meglumine