Estimated Supply of Organ Donors After Circulatory Determination of Death: A Population-Based Cohort Study FREE

To the Editor: Increased use of donors after circulatory determination of death (DCDD) has been advocated as the most viable method for increasing the supply of transplantable organs.¹ However, the number of potential DCDD in the United States remains uncertain, with estimates accruing from retrospective single-center experiences in adult^2- 3 or pediatric^4- 5 hospitals. We conducted a prospective, population-based cohort study to estimate the potential increase in the supply of deceased donors that might accrue from optimal use of controlled DCDD, donors in whom life-sustaining therapies are withdrawn and organs are recovered following the loss of spontaneous circulation.

In-hospital deaths were evaluated throughout the highest-volume US donor service area (DSA) comprising eastern Pennsylvania, southern New Jersey, and Delaware. The DSA's 134 acute care hospitals were stratified by their numbers of deceased donors in the preceding year (level 1, ≥20; level 2, 10-19; level 3, 5-9; level 4, ≤4), median intensive-care-unit bed number, racial distribution of the local county, and geographic region. A 100% sample (23 hospitals) was selected from strata including hospitals in which 10 or more deceased donors were available in the prior year, along with a 25% stratified random sample (27 additional hospitals) from the 111 remaining lower-volume hospitals.

All patients dying within 90 minutes following withdrawal of life-sustaining therapy from July 1, 2008, through June 30, 2009, who were 70 years or younger and had no exclusionary diagnoses (eg, metastatic cancer, human immunodeficiency virus, West Nile virus) were identified. Clinical and demographic data were abstracted. Using prespecified criteria developed by surgeons experienced in using DCDD organs (Table 1), each organ was categorized as optimal, suboptimal, or ineligible for transplantation, and each donor was similarly categorized based on the highest ranking assigned to one of his or her organs.

Data were extrapolated to the entire DSA by multiplying the total number of donors identified at each hospital level by the inverse of the proportions of hospitals within each level included in the study. Confidence intervals were generated from Poisson distributions using Stata 10.1 (StataCorp, College Station, Texas). The study was exempt from institutional review board review.

Among 39 993 in-hospital deaths in the DSA during the study period, 21 802 (54.5%) occurred at the 50 study hospitals. Of these, 130 (0.60%) were potentially eligible DCDD, including 52 (0.24%) optimal DCDD (eligible to donate ≥1 optimal organ) and 78 (0.38%) suboptimal DCDD (eligible to donate no optimal organs but ≥1 suboptimal organ). Of the potential DCDD, clinicians identified and referred 108 (49 optimal and 59 suboptimal; 83.1%) to the organ procurement organization (OPO) before withdrawal of life-sustaining therapy. The remaining 22 (3 optimal and 19 suboptimal) were identified through medical record review.

During the same period, 683 deaths (1.71% of all deaths) were prospectively or retrospectively identified as medically eligible donors after neurological determination of death. Table 2 provides the expected proportionate increases in this supply of deceased donors that could be obtained if all potential controlled DCDD were identified and referred to OPOs before withdrawal of life-sustaining therapy.

These findings suggest that optimal identification and management of potential controlled DCDD could increase the supply of deceased donor organs, but by no more than 25%. If only optimal DCDD were used, as has been advocated,⁶ DCDD would be unlikely to expand the deceased donor supply by more than 10%.

These findings likely represent best-case estimates given intentionally optimistic study assumptions. We based donor classifications on the standards of highly experienced DCDD transplant surgeons, allowed up to 90 minutes following withdrawal of life-sustaining therapy (rather than a more traditional 60 minutes) to accommodate the thresholds of some surgeons for procuring kidneys or lungs, and assumed that barriers to simultaneously procuring both abdominal and thoracic organs from DCDD can be overcome.