Related Experiment Video
Updated: Aug 16, 2026
In Vitro Thrombosis Test for Ventricular Assist Devices
Published on: March 21, 2025
An in vitro study comparing the effects of Hextend, Hespan, normal saline, and lactated ringer's solution on
Stephen E Dailey1, Christopher B Dysart, Daniel R Langan
1Mayo School of Health Sciences, Rochester, MN 55905, USA.
Objective:
The purpose of this study was to determine if 6% HES 450/0.7 (hydroxyethyl starch 450/0.7) in normal saline (Hespan) and 6% HES 450/0.7 in lactated Ringer's solution (Hextend) have the same inhibition of the intrinsic coagulation pathway and platelet function. Multiple studies have suggested that 6% Hespan inhibits coagulation and increases chest tube drainage and transfusion requirements in cardiac surgical patients. There have been few studies of the effects of 6% Hextend, a relatively new plasma volume expander, on coagulation and the results thus far have been mixed.
Design:
A prospective in vitro study.
Setting:
A large academic medical center.
Participants:
Blood was collected from 30 healthy volunteers. Interventions : The blood was fractionated and diluted by 30% with Hextend, Hespan, normal saline, and lactated Ringer's solutions, with a native sample for a control.
Measurements And Main Results:
Primary outcome measures were thromboelastography and activated partial thromboplastin time (APTT). For each of the TEG parameters, there was no difference between samples diluted with Hextend compared with Hespan (p > or = 0.112 in all cases). APTT did not differ significantly between samples diluted with Hextend compared with Hespan (p = 0.562).
Conclusions:
This prospective in vitro study suggests that Hextend and Hespan, hydroxyethyl starch 450/0.7 in different base solutions, exhibit the same effect on platelet function as measured by the TEG.
