The Donor & Allocation

The contract between this chapter and the reader.

1. 1. Classify donor types and their relative outcomes.
2. 2. Distinguish donation after brain death from donation after circulatory death.
3. 3. Assess deceased-donor kidney quality, including KDPI.
4. 4. Explain why living donation gives the best outcomes.
5. 5. Describe the principles of deceased-donor allocation.
6. 6. Explain longevity matching and the utility–equity balance.
7. 7. Recognise the priority given to highly sensitized and other groups.
8. 8. Weigh accepting a marginal organ against remaining on the waitlist.
9. 9. Identify the ethical tensions in organ allocation.

A sixty-second reading. Each bullet stands alone.

• Donors are living or deceased; living-donor grafts have the best survival.
• Deceased donation is after brain death (DBD) or after circulatory death (DCD).
• DCD kidneys have more delayed graft function from warm ischemia but acceptable long-term outcomes.
• Kidney quality is graded by the Kidney Donor Profile Index (KDPI); a higher KDPI means lower expected graft longevity.
• Pre-emptive living-donor transplantation, before dialysis, gives the best results.
• Deceased-donor allocation balances utility (best outcomes) against equity (fair access).
• Longevity matching directs the best kidneys to recipients with the longest expected survival.
• Highly sensitized candidates, children, and prior living donors receive allocation priority.
• For an individual, accepting a higher-KDPI or DCD organ now is weighed against waiting for a better offer that may not come.
• Even a marginal kidney usually offers a survival benefit over remaining on dialysis.
• The supply of donor kidneys falls far short of demand, forcing difficult allocation choices.
• Allocation embodies a genuine tension between utility and equity.
• Marginal kidneys can be assessed with biopsy or machine perfusion before use.

The medical core. An expert should agree the donor and allocation are fully covered here.

Why it matters at the bedside

Every transplant begins with two scarce things: a donor kidney and a fair way to decide who receives it. The quality of the organ shapes the outcome, and the rules that allocate it shape who gets a chance at all. This chapter is where biology meets ethics — grading the kidney, and weighing utility against equity in giving it away.

Donor types

• Donors are living or deceased. A living donor gives the best outcomes — the transplant is planned, ischemia is short, and the kidney is healthy — and can be related, unrelated, or arranged through paired exchange. Deceased donors supply most kidneys but, on average, give shorter graft survival, and within them quality varies widely.

DBD and DCD

• Deceased donation comes in two forms. Donation after brain death (DBD) is the standard deceased pathway. Donation after circulatory death (DCD) follows the cessation of circulation and entails a period of warm ischemia, which raises the rate of delayed graft function — yet long-term outcomes are acceptable, and DCD has substantially expanded the donor pool.

Assessing kidney quality: KDPI

• Deceased-donor kidney quality is summarised by the Kidney Donor Profile Index, a 0–100% scale derived from donor factors — age, cause of death, DCD status, terminal creatinine, comorbidities. A higher KDPI predicts lower graft longevity. For marginal kidneys, a biopsy or machine perfusion helps decide whether — and for whom — the organ should be used.

Why living donation is best

• Living-donor transplantation consistently gives superior graft and patient survival, and pre-emptive living donation — transplanting before dialysis ever starts — gives the best results of all. The donor's risk, though small, is real and is the subject of its own shared decision (the special-situations chapter).

Expanding the donor pool

• Because demand vastly outstrips supply, the pool is deliberately widened: extended-criteria and higher-KDPI donors, DCD donors, and donors with treatable or transmissible-risk infections (such as hepatitis C, now curable) are used with informed consent. The recurring question is whether to accept a marginal organ now or wait — a genuine point of equipoise.

Deceased-donor allocation: utility and equity

• Allocating scarce deceased kidneys means balancing two goods that pull apart. Utility seeks the most life-years from each organ; equity seeks fair access regardless of how long or how well someone might do. Real allocation systems blend the two — weighing waiting time, sensitization, and outcome — and reasonable people disagree about the balance.

Longevity matching

• One expression of utility is longevity matching: directing the best kidneys (lowest KDPI) to the recipients expected to survive longest (lowest Estimated Post-Transplant Survival score), so that a high-quality organ is not lost to a recipient who will not live to use it, and a marginal organ is not given to someone who would have benefited most from the best.

Priority groups

• Equity is built in through priority. Highly sensitized candidates (high cPRA), who would otherwise almost never match, are prioritised; children are prioritised for growth and life-years; prior living donors are prioritised in reciprocity; and waiting time accrues weight. These priorities are the system's answer to fairness.

The accept-or-wait decision

• For the individual patient, an organ offer poses a values-laden choice: accept a higher-KDPI or DCD kidney now, or decline and wait for a better one that may never come while dialysis mortality accrues. The crucial, often-missed fact is that even a marginal kidney usually confers a survival benefit over remaining on dialysis — so reflexive declining can cost the patient years.

Ethics and the supply–demand gap

• Underlying everything is scarcity: far more people need kidneys than there are kidneys to give. That gap is what forces the utility–equity tension, drives the use of marginal organs, and produces disparities in access — by geography, blood group, and sensitization — that allocation policy tries, imperfectly, to address.

Five fully-built tables.

Table A — Donor types and outcomes

Table B — Kidney quality (KDPI)

Table C — Allocation principles

Table D — Priority groups

Table E — Accept versus wait

Visualise & Map

Numbered rules. These numbers are the cross-reference handle for the cases and flowcharts.

Clinical Reasoning

Five cases. Each stops you at a decision before it answers it.

Exhaustive. Every rule in the chapter is here.

Safety & Evidence

Panel A — Red flags

Panel B — NEVER DO

Anti-patterns clinicians fall into. Each becomes a Level 22 distractor.

The grade reflects strength of evidence, not importance.

Patient Decisions

Outcomes as natural frequencies. Figures are representative; the direction of effect is given where precise numbers are uncertain.

Decisions where the right answer depends on the patient's values and situation, not the evidence alone.

Effective-care decisions (not preference-sensitive)

• Grading kidney quality by KDPI — a defined index.
• Requiring crossmatch compatibility — immunologic safety dictates it.
• Screening donors for transmissible infection and malignancy — standard of care.
• Applying the allocation policy's longevity-matching and priority rules — set at system level.

The conversation rehearsed as a skill. Numbers trace to Level 14.

Apply & Test

Pre-rounds compression. Rules only.

Active recall. At least one card per objective.

Micro-teaching for rounds. Two scenarios, five steps each.

Metacognition anchored to this chapter's tensions. No answers provided.

1. 1. Utility would give every good kidney to the youngest, healthiest recipient; what is lost if equity is sacrificed to outcomes — and vice versa?
2. 2. A marginal kidney usually beats dialysis, yet declining feels safer; how do you counsel a patient toward a choice that is statistically right but emotionally hard?
3. 3. Expanding the pool with riskier organs saves lives in aggregate but shifts risk onto individuals; how do you hold both truths when consenting one patient?
4. 4. The supply–demand gap is the root of every hard allocation choice; how much of that scarcity is fixed, and how much is a failure of living donation and policy we could change?
5. 5. Allocation rules encode a society's values; whose values are they, and how would you know if they were unjust to people like your patient?

Nine items, each anchored in this chapter. At least one per objective.