Issue |
J Extra Corpor Technol
Volume 27, Number 4, December 1995
|
|
---|---|---|
Page(s) | 197 - 200 | |
DOI | https://doi.org/10.1051/ject/1995274197 | |
Published online | 18 August 2023 |
Original Article
Correlation of ACT as Measured with Three Commercially Available Devices with Circulating Heparin Level during Cardiac Surgery
Perfusion Technology Program, University of Iowa Hospitals and Clinics, Iowa City, Iowa
* Address correspondence to: Scott D. Niles, B.A., Perfusion Technology Program, 200 Hawkins Drive, Iowa City, Iowa 52242
Automated activated clotting time (ACT) is utilized as the primary means of assessing anticoagulation status for cardiopulmonary bypass (CPB) procedures. Influences on the clotting cascade during CPB such as hypothermia, hemodilution, and platelet dysfunction are known to affect ACT.
The recently introduced Thrombolytic Assessment System (T AS) has been reported to be less sensitive to changes in hemodilution and hypothermia during CPB than more conventional ACT devices. This study evaluated the ability of TAS, and two other commercially available automated ACT systems, the HemoTec and Hemochron, to correlate with circulating heparin levels. Reference standards for circulating heparin were determined by inactivation of factor Xa assay.
Nineteen patients undergoing moderate hypothermic CPB served as subjects for this investigation. Blood samples were obtained for study at four time periods: 1) baseline (control), 2) post heparin administration (300-400 U/kg) prior to CPB, 3) during CPB, and 4) post protamine. Study results demonstrated a high correlation between the HemoTec and Hemochron (r = 0.99), increased heparin dose response on CPB compared to pre-CPB activity (p < 0.05), and a significant (p<0.05) negative correlation between devices and patient hematocrit during CPB. Additionally, device correlation with anti-Xa assay during collection periods 2 and 3 showed negative correlations in each of the three devices evaluated.
We conclude that all automated devices tested demonstrated an inability to predict circulating heparin at levels necessary for CPB, and that these discrepancies become magnified during CPB procedures.
Key words: activated clotting time / anticoagulation / factor Xa inhibition assay / cardiopulmonary bypass
© 1995 AMSECT
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.