Reversal of Heparin with Protamine.
The data shown above are from a (simulated) 'normal' patient weighing 75 kg in whom approximately 100 separate estimates of Activated Clotting Time (ACT) have been made at 10 second intervals.
At the first arrow, an intravenous dose of 10,000 units of heparin has been administered and the ACT has risen rapidly to about 325 seconds.
About 10 minutes later, at the second arrow, the patient has been given 100 mgs of protamine. Note how the effect of the heparin has been rapidly reversed.
These data are shown in order to illustrate some of the features of the patient model and to demonstrate the rapid onset of effect of both Heparin and Protamine. However, it should be noted that in general terms, reversal of the anti-coagulant effect of heparin with protamine in patients on ECMO is almost never indicated - as it carries a very high risk of causing clotting within the circuit.