"Donation after circulatory determination of death" is the name we have currently settled on after "donation after cardiac death", "donation after circulatory death" and "non-heartbeating organ donation" have receded into history. This mechanism of organ donation has historically been rather underutilized and even now comprises merely 25% of Australia donations, according to the latest ANZICS statement. This topic has appeared as Question 10 from the second paper of 2022, where the candidates were asked for the process of determination of death, as well as the definition of "functional warm ischaemic time" and some rather detailed information about graft survival rates in DCD recipients. What follows is an attempt to distill the already concise Statement into some kind of pointform summary, so that all future DCCD questions may be covered.
The circulatory determination of death requires "irreversible cessation of circulation of blood in the body of the person". This means:
That last clause is to prevent people from becoming donors when they have in fact "autoresuscitated" after 1-2 minutes, i.e. the circulation spontaneously resumed for a period.
Question 10 from the second paper of 2022 askes for a definition of "functional warm ischaemic time", which is a term that appears in the ANZICS statement only once. Their definition is:
"The functional warm ischaemic time is the time from when the systolic blood pressure falls below 50 mmHg after withdrawal of cardiorespiratory support to cold perfusion and may be a better measure of ischaemic injury"
Better than what? Better than the agonal period:
"The agonal period is the time from withdrawal of cardiorespiratory support until circulatory arrest. ... It is limited to approximately 90 minutes in Australia and New Zealand so that if death has not occurred within this time frame the donation process is usually aborted"
What is the influence of this on graft function? Well: predictably, a graft that has been poorly perfused for longer will function poorly and may fail. These are times from
Because the CICM examiners complained that "knowledge of graft survival between different organs was... commonly incorrect", a mnemonic of some sort may be called for. LHP30,K60,L90? Everything near the epigastrium 30, kidneys 60, lungs 90? Also, kidneys and lungs measure their warm ischaemia time from an SBP of 50 mmHg, whereas for the heart the timer starts from 90 mmHg, and from the withdrawal of cardiorespiratory support for liver and pancreas. This timeline from Donate Life is probably best for people who might prefer to have the warm ischaemia timeframes described visually (with thanks to Dr Simon Wong, who found this):