Expanding the donor pool: effect on graft outcome

Development of the University of Wisconsin Donation after Cardiac Death Evaluation Tool

Background

Donation after cardiac death is a method by which severely neurologically injured patients not fulfilling brain-death criteria can donate organs.

Objective

To develop an evaluation tool that can be used to predict if a patient is a suitable candidate for donation after cardiac death.

Methods

The University of Wisconsin Donation After Cardiac Death Evaluation Tool assigns numeric values to observable clinical parameters to yield an overall predictive score of suitability for donation after cardiac death. This evaluation tool is typically utilized in a critical care unit to evaluate patients with a severe neurological injury, who do not meet brain-death criteria, and for whom the physician and family have chosen to terminally withdraw life support. Each patient is disconnected from a ventilator and observed for up to 10 minutes. Observations are then scored to yield a prediction of suitability for donation after cardiac death.

Results

Using the University of Wisconsin Donation After Cardiac Death Evaluation Tool, we were able to predict suitability for donation after cardiac death 83.7% of the time, within a 60-minute period and 74.4% of the time within a 120-minute period. The actual results using the tool were higher when clinical observations were included in the donation after cardiac death evaluation—an overall accuracy of 88.4%.

Simultaneous liver and kidney transplantation using donation after cardiac death donors: a brief report

Although the use of donation after cardiac death (DCD) donor organs has been shown to be a viable option for liver and kidney transplant recipients, outcomes after simultaneous liver and kidney (SLK) transplantation using DCD donors are less clear. We performed a retrospective analysis of 37 adult, primary SLK transplants performed at our center between January 1, 1998 and December 31, 2008. Thirty-two patients received donation after brain death (DBD) organs, and 5 patients received DCD organs. SLK recipients in the 2 groups were similar with respect to age, gender, race, body mass index, donor race, and donor body mass index. The calculated Model for End-Stage Liver Disease scores and pretransplant glomerular filtration rates were similar between the groups. DCD donors were younger and had shorter liver cold ischemia times. The median DCD donor warm ischemia time was 19.0 minutes (6.0-25.0 minutes). The recipient surgical times and hospital lengths of stay were comparable between the groups. Delayed graft function was more frequent in DCD renal allografts (80% versus 31%, P = 0.06). The 1-year graft survival rates for liver allografts (100% for the DCD group versus 94% for the DBD group) and kidney allografts (100% for the DCD group versus 94% for the DBD group) were similar. In conclusion, patients undergoing DCD SLK transplantation have comparable 1-year patient and graft survival rates and acceptable perioperative morbidity in comparison with DBD SLK transplant recipients. Although long-term outcomes remain unknown, the utilization of DCD organs for SLK transplantation should be considered a valid approach to safely expanding the donor organ pool.

Donor postextubation hypotension and age correlate with outcome after donation after cardiac death transplantation

BACKGROUND

Compared with standard donors, kidneys recovered from donors after cardiac death (DCD) exhibit higher rates of delayed graft function (DGF), and DCD livers demonstrate higher rates of biliary ischemia, graft loss, and worse patient survival. Current practice limits the use of these organs based on time from donor extubation to asystole, but data to support this is incomplete. We hypothesized that donor postextubation parameters, including duration and severity of hemodynamic instability or hypoxia might be a better predictor of subsequent graft function.

METHODS

We performed a retrospective examination of the New England Organ Bank DCD database, concentrating on donor factors including vital signs after withdrawal of support.

RESULTS

Prolonged, severe hypotension in the postextubation period was a better predictor of subsequent organ function that time from extubation to asystole. For DCD kidneys, this manifested as a trend toward increased DGF. For DCD livers, this manifested as increased rates of poor outcomes. Maximizing the predictive value of this test in the liver cohort suggested that greater than 15 min between the time when the donor systolic blood pressure drops below 50 mm Hg and flush correlates with increased rates of diffuse biliary ischemia, graft loss, or death. Donor age also correlated with worse outcome.

CONCLUSIONS

Time between profound instability and cold perfusion is a better predictor of outcome than time from extubation to asystole. If validated, this information could be used to predict DGF after DCD renal transplant and improve outcomes after DCD liver transplant.