4-4 Chapter 4: Heparin Management in Cardiopulmonary Bypass Surgery
Pre Bypass: Baseline
Running a sample prior to heparin is useful to gain an
understanding of the patient’s hemostasis performance.
The recommended test is a glass bead activated
differential heparinase panel. One channel runs a
glass bead activated test which is Sienco’s preferred
reagent for comprehensive hemostasis evaluation;
the other channel runs a heparin neutralized glass
bead activated test. The reason for running a heparin
neutralized test is to ensure that the baseline test has
not been compromised by some unexpected heparin
contamination or pre-administration. The Sonoclot
Signatures above show a baseline with a small amount
of unexpected heparin.
On Bypass: High Dose Heparin Therapy
High dose heparin management using the Sonoclot Analyzer’s ACT result is similar to using other ACT
instruments. The Sonoclot Analyzer also offers the added benefit of the Clot Rate result that quantifies
how fast the clot develops after the ACT result has been calculated. The objective of anticoagulant
management is to prevent clot formation. The Clot Rate result is a more direct measurement of heparin’s
effect of clot formation. Multiple researchers have found the Clot Rate result to be more specific to
heparin concentration than the ACT.
One recommended approach for comprehensive heparin management is to establish both ACT and
Clot Rate thresholds. Additional heparin is administered when either the ACT is below an established
threshold or the Clot Rate is above an established threshold. Typically, Clot Rate results are below 6
during high dose heparin therapy.
Post Bypass: Heparin Reversal and Hemostasis Restoration
There are two coagulation concerns after bypass: adequate heparin reversal and overall hemostasis
performance.
Since both residual heparin and coagulation factor deficiencies may be detected after protamine
administration, running two tests, one with and one without heparin neutralization, provides comprehensive
and specific results to characterize overall hemostasis performance.
In this post protamine example, the gbACT+ test showed
a prolonged ACT and reduced Clot Rate. These results
could indicate either residual heparin or inadequate
coagulation factors. The heparin neutralized version
of the gbACT+ test showed normal results for the
ACT and Clot Rate. The heparin neutralized test also
showed normal clot retraction. The amount of residual
heparin in this example can easily be missed with a
standard ACT.
Patient 2 Pre
Minutes
0.0
5.0
10.0
15.0
20.0
25.0
30.0
Clot
Signal
0
25
50
75
100
125
Group Description
Style Time Patient Test Application Operator Result Range
Heparin Neutralized
Control
glass bead activated tests
Patient 2 Post
Minutes
0.0
5.0
10.0
15.0
20.0
25.0
30.0
Clot
Signal
0
25
50
75
100
125
Group Description
Style Time Test Application Result Range Comment
Control
Heparin Neutralized
glass bead activated tests
