Patient was primary CABG elective with normal BMI and no documented co-morbidities, allergies and sensitivities or relevant clinical history.

The Clinical Perfusion team was alerted to an elevated baseline ACT result (averaging 400 on re-testing).

The possibility of accidental infusion of Heparin was floated and discounted although a plain and Heparinase TEG test was started.

The on call consultant hematologist was consulted and they confirmed no evidence of coagulopathy with normal PT, PTT and INR.  There was no evidence of any exposure to anti coagulants in the pre op period on the ward and platelet inhibitors had all been stopped well before admission.

The TEG trace was inspected.  The Heparinase TEG showed an extended R time of 22 minutes, the plain test was still latent at 40 minutes, with no polymerization.

Accidental Heparin infusion was again suggested but the extended R time in the Heparinase TEG was held up as evidence that there was indeed an underlying coagulopathy.

Perfusionist, consultant Surgeon and Anesthetist discussed safety and possible way forward.  OP-CAB was discounted, retest ACT after administration of Protamine was also discounted.

Despite the seeming absence of a reason for the coagulopathy and extended ACT the team agreed that bypass with heparin would still be attempted.

Perfusion team set up pre and post membrane transducers which is not normal practice.  The operation proceeded with standard anticoagulation protocol.  Pre bypass ACT was >1000.  As a precaution the Perfusionist conducted a circuit RAP entirely removing the bypass prime from the circuit and recirculated for 5 mins.  After inspection of the membrane fibers and reservoir filters and final confirmation with the MDT, bypass was initiated.

The bypass proceeded uneventfully with trans-membrane pressures, and all bypass parameters within expected ranges.

The patient was successfully weaned from bypass and decannulated.  After Heparin reversal the ACT was measured and the result was 120.

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