HEPARIN ADMINISTRATION AND MONITORING FOR NEUROANGIOGRAPHY

PURPOSE: To establish the optimal protocol of heparin administration d uring interventional neuroradiology. METHODS: We assessed 100 cases of neuroangiography, including endovascular surgery, and measured activa ted coagulation time before and 5 minutes after heparin administration , and before and 5 minutes after protamine neutralization. In some cas es actual heparin concentration was assayed using a chromogenic substr ate technique. RESULTS: The actual plasma heparin concentration signif icantly correlated with the dose of heparin administered intravenously (r=.98; P<.0001) and changes in activated coagulation time (r=.85; P< .0001). The change in activated coagulation time significantly correla ted with the dose of heparin injected intravenously (r=.54, P<.0001). The ratio of change in activated coagulation time significantly correl ated with time elapsed after heparin administration (r=-.70, P <.0001) . CONCLUSIONS: The activated coagulation time is useful in monitoring administration and neutralization of heparin during neuroangiography, and a bolus injection of 60 U/kg heparin should be adequate to carry o ut neuroangiography for 75 minutes safely, even for endovascular surge ry.