title: Comparison of three methods to estimate heparin loading dose for cardiopulmonary bypass.
abstract: Three available methods used to determine heparin loading dose were studied to determine the most reliable method for reaching a target pre-bypass activated clotting time (ACT) of 510 seconds. One hundred and seven patients were randomly assigned to one of three treatment methods: A) 300 units/kg; B) Hemostasis Management System (HMS); C) RX/DX. Five different lots of heparin were assigned to Groups A and B, and Group C had one heparin lot. Different lots were used to account for possible variations in heparin activity. Post-skin incision ACTs, post-heparin pre-bypass ACTs, and heparin loading doses were compared. The mean and standard deviation of the post-heparin pre-bypass ACTs were used to determine which method was most reliable to obtain a desired ACT. There was no statistical difference between different heparin lots. There was no difference in the post-heparin ACTs for the three methods (A:487 +/- 135 vs. B:474 +/- 105 vs. C:474 +/- 111 sec). There was a statistically significant difference between the standard deviation for the HMS and 300 u/kg standard deviations (p < 0.05). The HMS has the smallest deviation which makes it the most reliable predictor of heparin loading doses to reach a target ACT for cardiopulmonary bypass.
authors.affiliation: Medical University of South Carolina, Program in Extracorporeal Circulation Technology, Charleston, USA.
authors.forename: T D
authors.initials: TD
authors.lastname: Clark
authors.forename: J M
authors.initials: JM
authors.lastname: Ecklund
authors.forename: M M
authors.initials: MM
authors.lastname: McCall
authors.forename: D R
authors.initials: DR
authors.lastname: Wolk
authors.forename: J B
authors.initials: JB
authors.lastname: Riley
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000925:Anticoagulants / Q000008:administration & dosage* / Q000097:blood; D001777:Blood Coagulation / Q000187:drug effects*; D001827:Body Height; D001835:Body Weight; D002315:Cardiopulmonary Bypass; D062109:Dermatologic Surgical Procedures; D005544:Forecasting; D006488:Hemostasis, Surgical; D006493:Heparin / Q000008:administration & dosage* / Q000097:blood; D006801:Humans; D015203:Reproducibility of Results; D014914:Whole Blood Coagulation Time