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Artifact of blood pressure recording using heparin-filled catheter: effects on blood pressure and coagulation
V Martin1, M L Wiesel, A Beretz
1Laboratoire de Pharmacologie et de Physiopathologie Cellulaires, Faculté de Pharmacie, Université Louis Pasteur de Strasbourg, France.
Insights
A new "low heparin" protocol for arterial catheterization prevents blood clots without causing significant anticoagulation or blood pressure changes. This method minimizes heparin
Area of Science:
- Cardiovascular research
- Coagulation science
- Medical device engineering
Background:
- Arterial catheterization for blood pressure monitoring can lead to catheter clogging due to coagulation activation.
- Standard protocols use heparinized saline, which can cause significant anticoagulation and affect blood pressure.
- Unwanted heparin infusion can alter physiological parameters during experiments.
Purpose of the Study:
- To develop and evaluate a modified "low heparin" protocol for arterial catheterization.
- To minimize heparin-induced anticoagulation and blood pressure changes during prolonged monitoring.
- To prevent catheter occlusion while maintaining physiological stability in rats.
Main Methods:
- Rats were implanted with arterial catheters for 6-hour blood pressure monitoring.
- A standard protocol using 100 IU/ml heparin in saline was compared to a modified protocol with 0.1 IU/ml heparin.
- Activated partial thromboplastin time (APTT) was measured to assess anticoagulation.
- Blood pressure was monitored throughout the procedures.
Main Results:
- The standard protocol significantly increased APTT (from 27s to >240s), indicating substantial anticoagulation.
- The "low heparin" protocol resulted in no significant change in APTT, suggesting minimal heparin injection.
- The "low heparin" protocol avoided significant blood pressure alterations observed with the standard method.
Conclusions:
- The modified "low heparin" protocol effectively prevents catheter clogging.
- This protocol significantly reduces systemic heparin administration, avoiding unwanted anticoagulation and hemodynamic effects.
- The "low heparin" approach is recommended for arterial catheterization procedures requiring physiological stability.
Abstract:
A usual complication of catheterization procedures of arteries for blood pressure recording is the clogging of catheters due to activation of coagulation. This is usually avoided by filling the catheters with a heparinized saline solution. We have studied rats implanted with four catheters, one of which was used to monitor blood pressure for 6 h. Catheters were filled with 100 IU/ml heparin in saline. Using this standard protocol, approximately 50-200 IU of heparin were injected into the animals. This induces significant anticoagulation. The activated partial thromboplastin time (APTT) increased from 27 s to more than 240 s. We devised a modified "low heparin" protocol, in which the concentration of heparin in the wash solution of the catheters was lowered from 100 to 0.1 IU/ml, and the pressor transducer was back-perfused with saline solution without heparin. Using this new protocol, no significant modification of the APTT was observed, indicating that only trace amounts of heparin were injected. Subsequent controlled administration of heparin induced a significant decrease in blood pressure. To avoid all effects associated with this unwanted infusion of heparin, mainly a decrease in blood pressure and a major anticoagulant effect, we suggest the use of such "low heparin" catheterization protocol.