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Using activated clotting time to estimate intraoperative aprotinin concentration
Yusuke Iwata1, Toru Okamura, David Zurakowski
1Children's National Heart Institute, Children's National Medical Center, Washington, DC, USA.
Perfusion
|January 23, 2010
Summary
Measuring aprotinin blood levels during cardiopulmonary bypass can be estimated using the difference between celite and kaolin activated clotting time (ACT). This simple method may help reduce renal complications from excess aprotinin dosage.
Area of Science:
- Biochemistry
- Pharmacology
- Medical Devices
Background:
- Aprotinin use in cardiopulmonary bypass is linked to renal dysfunction.
- Excess aprotinin is renally excreted.
- Accurate monitoring of aprotinin levels is crucial.
Purpose of the Study:
- To investigate if the difference between celite and kaolin activated clotting time (ACT) can estimate aprotinin blood levels.
- To explore a simpler method for monitoring aprotinin during cardiopulmonary bypass.
Main Methods:
- Porcine blood was treated with varying concentrations of aprotinin (0-400 KIU/mL).
- Celite and kaolin ACT were measured using Hemochron 401 machines at 37°C and 20°C.
- A generalized estimating equation (GEE) model was employed to correlate ACT differences with aprotinin concentration.
Main Results:
- A significant exponential relationship was found between aprotinin concentration and the celite-kaolin ACT difference.
- The correlation was strong at both 37°C (R² = 0.858) and 20°C (R² = 0.743).
Conclusions:
- The ACT difference offers a simple, cost-effective method for estimating aprotinin levels.
- This technique could enable patient-specific aprotinin dosing.
- Reduced risk of postoperative renal complications is a potential benefit.
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