The details of the incident are limited but it suggests that administration of protamine may have occurred at the wrong point of the procedure, resulting in clot in the bypass circuit.

"Took over from colleagues. Off bypass, suckers on and no protamine given. I was asked by the surgeon to keep the suckers on and give back the bleeding volume until (time +10mins). When asked to give volume again, I couldn't. Revolutions were up but no flow was going through. I told the surgical team that there was a problem with the arterial pipe. The surgeon said that it could be a clot and removed it at (time +19minutes). Tried to flush the circuit but couldn't do that either. I bagged the volume and put that into the cell saver as the patients MAPs were dropping. I then accessed the circuit and saw that the arterial line filter was clotted.

I then went round to ask when protamine was given and I was told "a few minutes ago" - but no defined time. I suspect that protamine was given without the knowledge of the MDT while the suctions were still on".