| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Ann Thorac Surg 2004;77:973-976
© 2004 The Society of Thoracic Surgeons
a The CardioVascular Center at The Chester County Hospital, West Chester, Pennsylvania, USA
b Department of Mathematics, West Chester University of Pennsylvania, West Chester, Pennsylvania, USA
Accepted for publication August 6, 2003.
* Address reprint requests to Mr Aylsworth, The CardioVascular Center at The Chester County Hospital, 701 East Marshall St, West Chester, PA 19380, USA
e-mail: caylsworth{at}cchosp.com
BACKGROUND: Accurate control of the anticoagulation level is important for safe initiation of cardiopulmonary bypass. Using the Hemochron Jr., we consistently noted a higher than customary heparin dose required to achieve an activated clotting time (ACT) that, according to the literature and our quality standards, should be more than 480 seconds. This study was designed to determine whether there existed a significant difference in ACT values measured by the newer Hemochron Jr. and the older Hemochron 801 assay system.
METHODS: A total of 30 patients underwent cardiovascular surgical procedures requiring heparinization (300 U/kg). Multiple samples for measurement of the ACT were obtained from all patients before heparinization, after heparinization, during cardiopulmonary bypass, and after protamine administration. Arterial samples were collected, and ACT was determined simultaneously on the same sample using both Hemochron Jr. and Hemochron 801. Activated clotting time data were analyzed with a linear mixed model using an unstructured variance-covariance matrix.
RESULTS: Descriptive statistics on all heparinized patients revealed that the Hemochron Jr. yielded ACT results that on average were 121.28 seconds lower than the determination by the standard Hemochron 801 on the same sample of blood. This difference was -139.04 in on-pump cases and -90.51 in off-pump cases, primarily a function of the fact that higher heparin doses and therefore longer ACTs were used in patients having operations using the heart-lung machine. From the linear mixed model, the estimated average paired difference between the Hemochron Jr. and Hemochron 801 was found to be -86.03, yielding a highly significant test statistic (t28 = -6.18; p < 0.0001).
CONCLUSIONS: Lower ACT values determined by Hemochron Jr. are consistent with higher, clinically acceptable ACT values as measured by the Hemochron 801. These findings would suggest that safe levels of anticoagulation are determined in part by the specific assay used.
This article has been cited by other articles:
|
|
 |
|
  C. W. Baird, D. Zurakowski, B. Robinson, S. Gandhi, L. Burdis-Koch, J. Tamblyn, R. Munoz, K. Fortich, and F. A. Pigula Anticoagulation and Pediatric Extracorporeal Membrane Oxygenation: Impact of Activated Clotting Time and Heparin Dose on Survival Ann. Thorac. Surg., March 1, 2007; 83(3): 912 - 920. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. A Spinler, A. K Wittkowsky, E. A Nutescu, and M. A Smythe Anticoagulation Monitoring Part 2: Unfractionated Heparin and Low-Molecular-Weight Heparin Ann. Pharmacother., July 1, 2005; 39(7): 1275 - 1285. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S Svenmarker, M Appelblad, E Jansson, and S Haggmark Measurement of the activated clotting time during cardiopulmonary bypass: differences between Hemotec(R) ACT and Hemochron(R) Jr apparatus Perfusion, September 1, 2004; 19(5): 289 - 294. [Abstract] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
