Effect of Albumin in Combination With Mannitol on Whole-blood Coagulation In Vitro Assessed by Thromboelastometry

Background: Albumin and mannitol may interfere with hemostasis, but their coinfluence is unclear. We aimed to determine the effects of albumin alone and in combination with mannitol or Ringer acetate (RAC) on hemostasis in crossover in vitro study. Materials and Methods: From citrated fresh whole blood withdrawn from 10 volunteers, we prepared 2.5, 5, 10, 15, and 20 vol% dilutions of 4% albumin (Alb group). Each sample was thereafter diluted by 15% mannitol (Alb/Man group) or RAC (Alb/RAC group) at a ratio of 9:1. Using thromboelastometry, FibTEM (fibrinogen ROTEM) and ExTEM (extrinsic ROTEM) tests were performed. Results: A 20 vol%, but not 2.5 to 15 vol% dilution of albumin caused a prolonged clot formation time, α-angle decrease, and maximum clot firmness (MCF) weakening compared with undiluted sample ( P <0.05). Clot formation time prolonged more in Alb5/Man than in Alb5 and Alb5/RAC dilution ( P <0.05). In Alb2.5/Man, Alb10/Man, and Alb15/Man, dilution α-angle was lower than in corresponding Alb/RAC and Alb-group dilutions ( P <0.05). In ExTEM, MCF decreased similarly in every dilution of Alb/Man and Alb/RAC compared with Alb group ( P <0.05). In FibTEM, MCF decreased more in Alb10/Man than in Alb10/RAC dilution ( P <0.05). Conclusions: In up to 15 vol% dilutions, albumin alone did not impair hemostasis in vitro, but in combination with mannitol or RAC coagulation was disturbed similarly at most concentrations. There was some significant additional effect with mannitol at certain concentrations. Our results indicate that coadministration of mannitol and albumin needs further study in vivo.