CCTC Organ Procurement and Preservation 5 — Questions and Answers
Question 1: What is the significance of the 'warm ischemia time' in donation after circulatory death (DCD) procurement compared to donation after brain death (DBD)?
- Warm ischemia time is irrelevant in DCD procurement
- DCD organs experience functional warm ischemia before cross-clamp, increasing susceptibility to ischemia-reperfusion injury (Correct answer)
- DBD organs have longer warm ischemia times than DCD organs
- Warm ischemia only affects heart procurement, not abdominal organs
Correct answer: DCD organs experience functional warm ischemia before cross-clamp, increasing susceptibility to ischemia-reperfusion injury
In DCD, organs are exposed to a period of functional warm ischemia (hypotension and hypoxia before asystole and cross-clamp) that does not occur in DBD, making DCD organs more vulnerable to ischemia-reperfusion injury.
Question 2: Which organ is typically procured LAST during a multi-organ procurement surgery to allow maximal perfusion time for other organs?
- Liver
- Kidneys (Correct answer)
- Pancreas
- Heart
Correct answer: Kidneys
Kidneys are typically procured last because they can tolerate longer cold ischemia times (up to 36 hours), while thoracic organs and the liver require earlier removal due to shorter acceptable ischemic windows.
Question 3: A transplant coordinator is managing a DCD donor who has been withdrawn from life support. After 60 minutes, the donor has not progressed to asystole. What is the standard protocol?
- Continue waiting indefinitely until asystole occurs
- Abandon the procurement per standard DCD protocols that specify a maximum observation period (Correct answer)
- Administer vasopressors to hasten the process
- Begin procurement while the donor still has a pulse
Correct answer: Abandon the procurement per standard DCD protocols that specify a maximum observation period
Standard DCD protocols specify a maximum observation period (typically 60-90 minutes depending on organ type) after which procurement is abandoned to avoid procuring organs with excessive warm ischemia time.
Question 4: What is the role of heparin administration during organ procurement, and when is it typically given?
- Heparin is given to the recipient only, not the donor
- Heparin is administered to the donor before cross-clamp to prevent intravascular clotting in the procured organs (Correct answer)
- Heparin is added to the preservation flush solution only
- Heparin is contraindicated in organ procurement due to bleeding risk
Correct answer: Heparin is administered to the donor before cross-clamp to prevent intravascular clotting in the procured organs
Heparin is administered intravenously to the donor before aortic cross-clamp to prevent microvascular thrombosis in the organs during the ischemic period, ensuring better perfusion when flushed.
Question 5: Which biomarker measured during normothermic machine perfusion is the most reliable indicator of liver viability?
- Perfusate glucose level
- Bile production and lactate clearance (Correct answer)
- Perfusate color
- Perfusate temperature stability
Correct answer: Bile production and lactate clearance
Bile production demonstrates bile duct and hepatocyte function, while lactate clearance reflects mitochondrial aerobic metabolism; together they are the most validated viability markers during normothermic liver perfusion.
Question 6: What is the primary rationale for flushing procured organs with cold preservation solution at the time of cross-clamp?
- To sterilize the organ from bacterial contamination
- To rapidly cool the organ and reduce metabolic demand, minimizing ischemia-reperfusion injury (Correct answer)
- To remove all blood for serologic testing purposes
- To maintain normothermic conditions during transport
Correct answer: To rapidly cool the organ and reduce metabolic demand, minimizing ischemia-reperfusion injury
Rapid cooling with cold preservation solution (4°C) dramatically reduces cellular metabolism, decreasing ATP consumption and extending the viable preservation window by slowing ischemic injury.
Question 7: A procurement coordinator is offered a kidney from a 68-year-old donor with hypertension and a terminal creatinine of 1.4 mg/dL. Which tool is used to score marginal donor kidneys and guide acceptance decisions?
- MELD score
- Kidney Donor Profile Index (KDPI) (Correct answer)
- eGFR calculator only
- SOFA score
Correct answer: Kidney Donor Profile Index (KDPI)
The Kidney Donor Profile Index (KDPI) uses 10 donor factors including age, creatinine, hypertension, and diabetes to calculate a percentile score that predicts post-transplant graft survival relative to other donors.
CCTC Organ Procurement and Preservation 5
What is the significance of the 'warm ischemia time' in donation after circulatory death (DCD) procurement compared to donation after brain death (DBD)?