BACKGROUND: Cryopreservaton of packed human red blood cells requires the use of cryoprotectants. OBJECTIVE: The study assessed physiological parameters of 40 RBC units frozen with either 40% glycerol or 6.7% HES. METHODS: After thawing, they were suspended in NaCl or in 6% HES. Tests of Hct, Hb, Na+ and K+ ions, ATP, 2,3-DPG, pH and erythrocyte stability were measured 30 minutes and 24 hours after thawing. RESULTS: Hct was lower after thawing but did not differ significantly between two groups. Hb was lower after thawing, but was statistically significant higher in the HES group (43.8 g/unit vs 35.4 g/unit). K+ concentration increased after thawing and was significantly higher after 24 hours in the glycerol group (29.0 mEq/l vs 8.7 mEq/l). ATP concentration in the HES group was significantly lower (2.15 micromol/g) in comparison with the glycerol group (6.30 micromol/g) 24 hours after thawing. 2,3-DPG levels did not differ significantly between the methods. Stability of RBCs frozen in glycerol were better (94.58%) than RBCs frozen in HES (80.75%) measured 24 hours after thawing. ATP is better protected in erythrocytes frozen in glycerol than in HES. CONCLUSION: Erythrocytes frozen with HES preserved more hemoglobin than with glycerol. Membrane permeability for Na+ and K+ ions was preserved better with HES. HES compared to glycerol offered better protection for erythrocytes.
BACKGROUND: Cryopreservaton of packed human red blood cells requires the use of cryoprotectants. OBJECTIVE: The study assessed physiological parameters of 40 RBC units frozen with either 40% glycerol or 6.7% HES. METHODS: After thawing, they were suspended in NaCl or in 6% HES. Tests of Hct, Hb, Na+ and K+ ions, ATP, 2,3-DPG, pH and erythrocyte stability were measured 30 minutes and 24 hours after thawing. RESULTS: Hct was lower after thawing but did not differ significantly between two groups. Hb was lower after thawing, but was statistically significant higher in the HES group (43.8 g/unit vs 35.4 g/unit). K+ concentration increased after thawing and was significantly higher after 24 hours in the glycerol group (29.0 mEq/l vs 8.7 mEq/l). ATP concentration in the HES group was significantly lower (2.15 micromol/g) in comparison with the glycerol group (6.30 micromol/g) 24 hours after thawing. 2,3-DPG levels did not differ significantly between the methods. Stability of RBCs frozen in glycerol were better (94.58%) than RBCs frozen in HES (80.75%) measured 24 hours after thawing. ATP is better protected in erythrocytes frozen in glycerol than in HES. CONCLUSION: Erythrocytes frozen with HES preserved more hemoglobin than with glycerol. Membrane permeability for Na+ and K+ ions was preserved better with HES. HES compared to glycerol offered better protection for erythrocytes.