Outcome of transplantation using kidneys from controlled (Maastricht category 3) non-heart-beating donors

Implementation of donation after circulatory death kidney transplantation can safely enlarge the donor pool: A systematic review and meta-analysis

BACKGROUND

Donation after circulatory death (DCD) kidney transplantation has been introduced to address organ shortage. However, DCD kidneys are not accepted worldwide due to concerns about inferior quality. To investigate whether these concerns are justified, we performed a systematic review and meta-analysis to investigate DCD graft outcomes compared to donation after brain death (DBD).

MATERIALS AND METHODS

EMBASE, Medline, Cochrane, Web of Science and Google Scholar were searched from database inception until September 2020. Exclusion criteria were studies reporting on pediatric/dual kidney transplants, multi-organ transplants or studies including normothermic perfusion techniques. The primary outcome was graft survival. Secondary outcomes were primary non-function (PNF), delayed graft function (DGF), 3-months biopsy-proven acute rejection (BPAR), 1-year estimated Glomerular Filtration Rate (eGFR), patient survival, and urologic complications. A random-effects model was used for meta-analysis. Meta-regression analysis was performed in case of high between-study heterogeneity.

RESULTS

Fifty-one studies were included, comprising 73,454 DCD and 518,229 DBD recipients. One-year graft loss was increased in DCD recipients (death-censored: risk ratio (RR) 1.10 (95%-confidence interval (CI) 1.04-1.16), all-cause: RR 1.13 (95%-CI 1.08-1.19)). Ten-year graft loss was similar to DBD (death-censored: RR 1.02 (95%-CI 0.92-1.13), all-cause: RR 1.03 (95%-CI 0.94-1.13)). DCD recipients had an increased risk of PNF (RR 1.43 (95%-CI 1.26-1.62)), DGF (RR 2.02 (95%-CI 1.88-2.16)), and 1-year mortality (RR 1.10 (95%-CI 1.01-1.21)). No differences were observed for 3-months BPAR, ureter stenosis/leakage, 1-year eGFR and 10-year mortality.

CONCLUSION

Long-term DCD kidney transplant outcomes are similar to DBD despite a higher risk of PNF, DGF, and a 13% increased risk of graft loss in the first year after transplantation. These results should encourage implementation of DCD programs.

Using electronic AKI alerts to define the epidemiology of acute kidney injury in renal transplants

Background

Little is known regarding the impact of acute kidney injury (AKI) on renal transplant outcome. Our aim was to define the incidence and outcome of AKI in renal transplant patients using data collected from a national AKI electronic alert system

Methods

The study represents a prospective national cohort study collecting data on 1224 renal transplants recipients with a functioning renal transplant, between April 2015 and March 2019.

Results

Four hundred forty patients experienced at least one episode of AKI giving an incidence rate of 35.4%. Sixty-four point seven% of episodes were AKI stage 1, 7.3% AKI stage 2 and 28% AKI stage 3. Only 6.2% of episodes occurred in the context of rejection. Forty-three point five% of AKI episodes were associated with sepsis. AKI was associated with pre-existing renal dysfunction, and a primary renal diagnosis of diabetic nephropathy. AKI was more prevalent in recipients from a donor after cardiac death (26.4% vs. 21.4%, p < 0.05) compared to the non-AKI cohort. Following AKI, 30-day mortality was 19.8% and overall mortality was 34.8%, compared to 8.4% in the non AKI cohort (RR 4.06, 95% CI 3.1–5.3, p < 0.001). Graft survival (GS), and death censored graft survival (DCGS) censored at 4 years, in the AKI cohort were significantly lower than in the non AKI group (p < 0.0001 for GS and DCGS).

Conclusion

The study provides a detailed characterisation of AKI in renal transplant recipients highlighting its significant negative impact on patient and graft survival.

The development of a predictive model of graft function in uncontrolled donors after circulatory death: validity of a pulsatile renal preservation machine cut-off value for kidney acceptance

BACKGROUND

The criteria for kidney suitability in uncontrolled donors after circulatory death (uDCD) procured after regional normothermic perfusion are based on macroscopic appearance and renal haemodynamic values with final renal resistance (FRR). However, these criteria have not been analysed to predict the future graft function. This study presents a model to predict the outcome in uDCD kidneys and define the predictive FRR value.

METHODS

All uDCD kidney transplants performed in our hospital from 2004 to 2016 were included. Donors and recipients and pre-transplantation data are described. The endpoint was glomerular filtration rate (GFR) ≥30 mL/min at 6 months after transplantation.

RESULTS

A total of 194 recipients were included. FRR in donors ≥60 years old was (mean ± SD) 0.27 ± 0.11 versus 0.22 ± 0.09 mmHg/mL/min in donors <60 years (P = 0.042). Kidney survival was 88.2% versus 84% at 12 months and 60.7% versus 30.8% at 120 months (P = 0.067). For the group of recipients from donors ≥60 years, the FRR was 0.37 ± 0.08 mmHg/mL/min in the GFR <30 mL/min group versus 0.18 ± 0.06 mmHg/mL/min in the GFR ≥30 mL/min group (P < 0.001). The value FRR ≥0.3 mmHg/mL/min predicts 59-79% of GFR <30 mL/min [odds ratio = 2.16, 95% confidence interval (CI) 1.80-6.40; P < 0.001]. The predictive accuracy of FRR for GFR by ROC curve was 0.968 (95% CI). The best cut-off for FRR was 0.3 mmHg/mL/min to predict GFR at 6 months with a sensitivity of 67%, specificity of 100%, positive predictive value of 83% and negative predictive value of 92%.

CONCLUSIONS

Our results suggest that in uDCD donors the combination of donor age ≥60 years together with FRR ≥0.3 mmHg/mL/min could predict poor outcome at 6 months after transplantation in low immunological risk recipients.

Donation after cardiac death kidneys are suitable for pediatric recipients

Despite the high number of children listed for kidney transplantation and shortage of deceased organ donors, there is reluctance to utilize DCD kidneys in pediatric recipients. We examined outcomes in pediatric kidney transplant patients who received a DCD kidney allograft. UNOS database was queried to examine outcomes in all pediatric kidney transplant recipients from 1994 to 2017. Pediatric status was defined as <18 years at the time of transplantation. Recipients were divided by DBD or DCD allograft status. Donor and recipient demographic data were examined. Patient and allograft survival was calculated, and Kaplan-Meier survival curves were generated. A P-value of <0.05 was considered to be significant. A total of 286 pediatric kidney transplant recipients received a DCD allograft. The donors in the DCD group were significantly younger than those in the DBD group (21.7 vs 23.3 years), with a higher KDPI (26.5% vs 22.9%). In the DCD group, the average age at transplant was younger (11.6 vs 12.9 years), with no difference in cold ischemia time or length of stay between the two groups. Rates of delayed graft function were higher in the DCD group, but despite this, there were no significant differences in allograft or patient survival between the groups. There is no difference in allograft survival in pediatric kidney transplant recipients who receive a DCD kidney allograft. DCD kidney allografts are suitable for transplantation in pediatric patients and can greatly expand the donor pool.

Enhanced immunosuppression improves early allograft function in a porcine kidney transplant model of donation after circulatory death

It remains controversial whether renal allografts from donation after circulatory death (DCD) have a higher risk of acute rejection (AR). In the porcine large animal kidney transplant model, we investigated the AR and function of DCD renal allografts compared to the non-DCD renal allografts and the effects of increased immunosuppression. We found that the AR was significantly increased along with elevated MHC-I expression in the DCD transplants receiving low-dose immunosuppression; however, AR and renal function were significantly improved when given high-dose immunosuppressive therapy postoperatively. Also, high-dose immunosuppression remarkably decreased the mRNA levels of ifn-g, il-6, tgf-b, il-4, and tnf-a in the allograft at day 5 and decreased serum cytokines levels of IFN-g and IL-17 at day 4 and day 5 after operation. Furthermore, Western blot analysis showed that higher immunosuppression decreased phosphorylation of signal transducer and activator of transcription 3 and nuclear factor kappa-light-chain-enhancer of activated B cells-p65, increased phosphorylation of extracellular-signal-regulated kinase, and reduced the expression of Bcl-2-associated X protein and caspase-3 in the renal allografts. These results suggest that the DCD renal allograft seems to be more vulnerable to AR; enhanced immunosuppression reduces DCD-associated AR and improves early allograft function in a preclinical large animal model.

Influence of Cold Ischemia Time in Kidney Transplants From Small Pediatric Donors

Background

Clinicians may be reluctant to transplant small pediatric kidneys that have prolonged cold ischemia time (CIT) for fear of an additional deleterious effect because pediatric grafts are thought to be more sensitive to ischemia. We aimed to assess the risks associated with transplantation of small pediatric kidneys with prolonged CIT.

Methods

We performed a retrospective cohort study examining US registry data between 1998 and 2013 of adult first-time kidney-only recipients of small pediatric kidneys from donors weighing 10 to 20 kg, stratified by CIT levels of 0 to 18 (n = 1413), 19 to 30 (n = 1116), and longer than 30 (n = 338) hours.

Results

All-cause graft survival by CIT groups at 1-year was 92%, 88%, and 89%, respectively. 1-year risk-adjusted graft survival hazard ratios were significantly higher with CIT of 19 to 30 hours (adjusted hazard ratios, 1.37; 95% confidence interval, 1.04-1.81) and somewhat higher with CIT greater than 30 hours (adjusted hazard ratios, 1.24; 95% confidence interval, 0.82-1.88) relative to recipients with CIT 0 to 18 hours. There was little variation in the effect of CIT on graft survival when restricted to single kidney transplants only and no significant interaction of CIT category and single kidney transplantation (P = 0.93).

Conclusions

Although prolonged CIT is associated with lower early graft survival in small pediatric donor kidney transplants, absolute decreases in 1-year graft survival rates were 3% to 4%.

Impact of Cold Ischemia Time in Kidney Transplants From Donation After Circulatory Death Donors

BACKGROUND

Deceased-donor kidneys are exposed to ischemic events from donor instability during the process of donation after circulatory death (DCD). Clinicians may be reluctant to transplant DCD kidneys with prolonged cold ischemia time (CIT) for fear of an additional deleterious effect.

METHODS

We performed a retrospective cohort study examining US registry data between 1998 and 2013 of adult first-time kidney-only recipients of paired kidneys (derived from the same donor transplanted into different recipients) from DCD donors.

RESULTS

On multivariable analysis, death-censored graft survival (DCGS) was comparable between recipients of kidneys with higher CIT relative to paired donor recipients with lower CIT when the CIT difference was 1 hour or longer (adjusted hazard ratio, [aHR], 1.02; 95% confidence interval [CI], 0.88-1.17; n = 6276), 5 hours or longer (aHR, 0.98; 95% CI, 0.80-1.19; n = 3130), 10 hours or longer (aHR, 1.15; 95% CI, 0.82-1.60; n = 1124) or 15 hours (aHR, 1.15; 95% CI, 0.66-1.99; n = 498). There was a higher rate of primary non function in the long CIT groups for delta 1 hour or longer (0.89% vs 1.63%; P = 0.006), 5 hours (1.09% vs 1.67%, P = 0.13); 10 hours (0.53% vs 1.78%; P = 0.03), and 15 hours (0.40% vs 1.61%; P = 0.18), respectively. Between each of the 4 delta CIT levels of shorter and longer CIT, there was a significantly and incrementally higher rate of delayed graft function in the long CIT groups for delta 1 hour or longer (37.3% vs 41.7%; P < 0.001), 5 hours (35.9% vs 42.7%; P < 0.001), 10 hours (29.4% vs 44.2%, P < 0.001), and 15 hours (29.6% vs 46.1%, P < 0.001), respectively. Overall patient survival was comparable with delta CITs of 1 hour or longer (aHR, 0.96; 95% CI, 0.84-1.08), 5 hours (aHR, 1.01; 95% CI, 0.85-1.20), and 15 hours (aHR, 1.27; 95% CI, 0.79-2.06) but not 10 hours (aHR, 1.47; 95% CI, 1.09-1.98).

CONCLUSIONS

These results suggest that in the setting of a prior ischemic donor event, prolonged CIT has limited bearing on long-term outcomes.

Outcomes for primary kidney transplantation from donation after Citizens' death in China: a single center experience of 367 cases

BACKGROUND

The cases of donation after brain death followed by circulatory death (DBCD) and donation after cardiac death (DCD) have been increased year by year in China. Further research is needed to understand in the outcomes and risk factors of delayed graft function (DGF) in order to minimize the risk of DGF and ameliorate its potential impact on long-term outcomes. This study was to explore the differences in outcomes between DBCD and DCD transplant and the main risk factors for DGF in DBCD.

METHODS

Retrospective analysis of the clinical data of 367donations after citizens' death kidney transplant procedures (donors and recipients) between July 2012 and August 2015 at our center.

RESULTS

During the study period, the donation success rate was 25.3%. 164 cases of DBCD and 35 cases of DCD had been implemented and 367 kidneys were transplanted. The incidence of DGF in DBCD group were significantly lower than that of DCD group (12.0% vs. 27.0%, p = 0.002). The 1-year percent freedom from acute rejection (AR) was significantly higher in DBCD group compared with it of DCD group (94% vs. 82%, p = 0.036). Multivariate logistic regression analysis of the kidney transplants revealed that the high risk factors for DGF after renal transplantation in DBCD were history of hypertension (Odds Ratio [OR] = 5.88, 95% CI: 1.90 to 18.2, p = 0.002), low blood pressure (BP < 80 mmHg) (OR = 4.86, 95% CI: 1.58 to 14.9, p = 0.006) and serum creatinine of donor (OR = 1.09, 95% CI: 1.03 to 1.16, p = 0.003) before donation.

CONCLUSIONS

The outcomes of DBCD could be better than DCD in DGF and AR. The main risk factors for DGF in DBCD kidney transplants are donors with a history of hypertension, low blood pressure, and serum creatinine of donor before donation.

Transplantation of kidneys from uncontrolled donation after circulatory determination of death: comparison with brain death donors with or without extended criteria and impact of normothermic regional perfusion

The aim of this study was to compare the outcomes of kidney transplants from uncontrolled DCD (uDCD) with kidney transplants from extended (ECD) and standard criteria donors (SCD). In this multicenter study, we included recipients from uDCD (n = 50), and from ECD (n = 57) and SCD (n = 102) who could be eligible for a uDCD program. We compared patient and graft survival, and kidney function between groups. To address the impact of preservation procedures in uDCD, we compared in situ cold perfusion (ICP) with normothermic regional perfusion (NRP). Patient and graft survival rates were similar between the uDCD and ECD groups, but were lower than the SCD group (P < 0.01). Although delayed graft function (DGF) was more frequent in the uDCD group (66%) than in the ECD (40%) and SCD (27%) groups (P = 0.08 and P < 0.001), graft function was comparable between the uDCD and ECD groups at 3 months onwards post-transplantation. The use of NRP in the uDCD group (n = 19) was associated with a lower risk of DGF, and with a better graft function at 2 years post-transplantation, compared to ICP-uDCD (n = 31) and ECD. In conclusion, the use of uDCD kidneys was associated with post-transplantation results comparable to those of ECD kidneys. NRP preservation may improve the results of uDCD transplantation.

Successful transplantation of kidneys from elderly circulatory death donors by using microscopic and macroscopic characteristics to guide single or dual implantation

Most kidneys from potential elderly circulatory death (DCD) donors are declined. We report single center outcomes for kidneys transplanted from DCD donors over 70 years old, using preimplantation biopsy Remuzzi grading to inform implantation as single or dual transplants. Between 2009 and 2012, 43 single transplants and 12 dual transplants were performed from elderly DCD donors. Remuzzi scores were higher for dual than single implants (4.4 vs. 3.4, p < 0.001), indicating more severe baseline injury. Donor and recipient characteristics for both groups were otherwise similar. Early graft loss from renal vein thrombosis occurred in two singly implanted kidneys, and in one dual-implanted kidney; its pair continued to function satisfactorily. Death-censored graft survival at 3 years was comparable for the two groups (single 94%; dual 100%), as was 1 year eGFR. Delayed graft function occurred less frequently in the dual-implant group (25% vs. 65%, p = 0.010). Using this approach, we performed proportionally more kidney transplants from elderly DCD donors (23.4%) than the rest of the United Kingdom (7.3%, p < 0.001), with graft outcomes comparable to those achieved nationally for all deceased-donor kidney transplants. Preimplantation biopsy analysis is associated with acceptable transplant outcomes for elderly DCD kidneys and may increase transplant numbers from an underutilized donor pool.

Uncontrolled non-heartbeating donors (types i-ii) with normothermic recirculation vs. heartbeating donors: evaluation of functional results and survival

OBJECTIVE

Non-heartbeating donors (NHBD) are an alternative to heartbeating donors (HBD). Our objective was to compare functional results and kidney survival from NHBDs and HBDs.

MATERIAL AND METHODS

A retrospective study comparing the results of 236 normothermically preserved kidneys from type i and ii type NHBDs with the results of 250 from HBDs that were transplanted in our center between 2005 and 2012. Homogeneity between groups was tested and we evaluated the presence of delayed graft function (DGF) associated with pretransplant variables of the donor and recipient.

RESULTS

Both groups show homogeneity in pretransplant characteristics in terms of: age, HLA incompatibilities, and recipient hemodialysis time. Average follow-up time was 33 months (range 0-87) for NHBDs and 38 months (range 0-90) for HBDs. 5.5% of NHBDs showed primary non-function (PNF) vs. 4% of HBDs (P=.42) and 80.9% of DGF vs. 46.8% of HBDs (P<.001). At the end of the follow-up, there were no statistically significant differences in the survival of grafts (92.8% for NHBD vs. 93.6% for HBD, P=.71) and recipients (99.1% NHBD vs. 98.6% HBD, P=.28).

CONCLUSIONS

Although the DGF percentage was greater for NHBDs, final creatinine as well as graft and recipient survival were similar for both groups. Therefore, in our experience, kidneys from NHBDs have similar results to those from HBDs and are an excellent source of organs for transplantation.

Preliminary results of transplantation with kidneys donated after cardiac death: a path of hope for organ transplantation in China

BACKGROUND

This article aims to explore the feasibility and effect of kidney transplantation (KT) from donation after cardiac death (DCD) donors in China.

METHODS

From July 2011 to April 2013, 94 DCD kidneys retrieved and transplanted by our centre were reviewed in this largest single-centre cohort study. Patients with and without delayed graft function (DGF) were compared between DCD KT cohorts. Estimated glomerular filtration rate (eGFR), post-operative complications and graft loss at different time points were recorded. Factors related to DGF were examined and analysed.

RESULTS

There was no primary non-function (PNF) graft observed from patients. DGF rate was 27.7%; and 1-year overall graft and patient survival rates were 95.7 and 98.9%, respectively. In the first 6 months post-transplantation, eGFR was significantly lower in the DGF group compared with the non-DGF group (46 versus 52 mL/min; P = 0.04); but the difference disappeared thereafter (50 versus 47 mL/min, after 1 year).

CONCLUSION

Despite early DGF and short-term observations, we are pleased to have this opportunity of sharing our initial experience and results, and justifying the continued DCD KT programmes in China.

Serum neopterin as an indicator of increased risk of renal allograft rejection

Acute rejection remains associated with poor graft outcome. An early predictor of acute renal transplant rejection is the long sought after goal for transplant immunologists. In this study we measured levels of serum neopterin at day 5 post-transplant in a cohort of 216 consecutive renal allograft recipients, and compared this with serum creatinine and acute rejection episodes during the first year post transplant. We compared serum neopterin in recipients from living donors (LD), donors after brain death (DBD) and donors after cardiac death (DCD). In all cases higher neopterin levels were correlated with acute rejection in the first year post transplant, but this was only significant in recipients of DCD kidneys who suffered acute cellular or vascular rejection (p=0.04, odds ratio 1.08, 95% CI 1.003-1.012). The neopterin/creatinine ratio, which takes into account the effect of kidney function on circulating neopterin levels, was significantly higher for all recipients who suffered biopsy proven cellular or vascular rejection in the first year post transplant, compared to all other patients (p=0.001, for an increase of 0.1, odds ratio=1.64, 95% CI 1.21-2.20). The ability to use non-invasive biomarkers in the transplant recipient has the potential to increase transplant survival for these patients.

Impact of cold ischemia time on graft survival among ECD transplant recipients: a paired kidney analysis

Delays in expanded criteria donor (ECD) kidney placement increases cold ischemia times (CIT) potentially leading to discard. The effect of increased CIT on ECD kidney transplant outcomes is unknown. We evaluated paired ECD kidneys (derived from the same donor transplanted to different recipients) from the SRTR registry transplanted between 1995 and 2009 (n = 17,514). To test the effect of CIT, we excluded paired transplants with the same CIT (n = 3286). Of 14,230 recipients (7115 donors) the median difference in CIT was 5 h (Q1 = 3 h, Q3 = 9 h). Delayed graft function (DGF) was significantly more likely between pairs with greater CIT (35% vs. 31%, p < 0.001) including substantially higher rates for CIT differences ≥ 15 h (42%). Overall graft loss was not significantly different between recipients with higher CIT relative to paired donor recipients with lower CIT (p = 0.47) or for pairs with differences of 1-3 h (p = 0.90), 4-9 h (p = 0.41), 10-14 h (p = 0.36) or ≥ 15 h (p = 0.10). Results were consistent in multivariable models adjusted for recipient factors. Although increasing cold ischemia time is a risk factor for DGF among ECD kidney transplants, there is no effect on graft survival which may suggest an important utility for donor kidneys that may not currently be considered viable.

Influence of CIT-induced DGF on kidney transplant outcomes

Increased cold ischemia time (CIT) predisposes to delayed graft function (DGF). DGF is considered a risk factor for graft failure after kidney transplantation, but DGF has multiple etiologies. To analyze the risk of CIT-induced DGF on graft survival, we evaluated paired deceased-donor kidneys (derived from the same donor transplanted to different recipients) in which one donor resulted in DGF and the other did not, using national Scientific Registry of Transplant Recipients data between 2000 and 2009. Of 54 565 kidney donors, 15 833 were excluded for mate kidney non-transplantation, 27 340 because both or neither kidney developed DGF and 2310 for same/unknown CIT. The remaining 9082 donors (18 164 recipients) were analyzed. The adjusted odds (aOR) of DGF were significantly higher when CIT was longer by ≥ 1 h (aOR 1.81, 95% CI 1.7-2.0), ≥ 5 h (aOR 2.5, 95% CI 2.3-2.9), ≥ 10 h (aOR 3.3, 95% CI 2.7-2.9) and ≥ 15 h (aOR 4.4, 95% CI 3.4-5.8) compared to shorter CIT transplants. In the multivariable models adjusted for recipient characteristics, graft survival between paired donor transplants, with and without DGF, were similar. These results suggest that DGF, specifically induced by prolonged CIT, has limited bearing on long-term outcomes, which may have important implications for kidney utilization.

Kidney transplantation from donation after cardiac death donors: lack of impact of delayed graft function on post-transplant outcomes

INTRODUCTION

Delayed graft function (DGF) is more common in recipients of kidney transplants from donation after cardiac death (DCD) donors compared to donation after brain death (DBD) donors.

METHODS

Single-center retrospective study to evaluate the impact of DGF on controlled (Maastricht category III) DCD donor kidney transplant outcomes.

RESULTS

From 10/01 to 6/08, 578 adult deceased donor kidney transplants were performed including 70 (12%) from DCD and 508 (88%) from DBD donors. Mean follow-up was 36 months. DCD donor kidney transplants had significantly greater rates of DGF (57% DCD vs. 21% DBD, p < 0.0001)) and acute rejection (29% DCD vs. 16% DBD, p = 0.018) compared to DBD donor kidney transplants, but patient and graft survival rates were similar. DBD donor kidney transplants with DGF (n = 109) had significantly greater rates of death-censored graft loss (12.5% DCD vs. 31% DBD), primary non-function (0 DCD vs. 10% DBD) and higher 2 year mean serum creatinine levels (1.4 DCD vs. 2.7 mg/dL DBD) compared to DCD donor kidney transplants with DGF (n = 40, all p < 0.04). On univariate analysis, the presence of acute rejection and older donor age were the only significant risk factors for death-censored graft loss in DCD donor kidney transplants, whereas DGF was not a risk factor.

CONCLUSION

Despite higher rates of DGF and acute rejection in DCD donor kidney transplants, subsequent outcomes in DCD donor kidney transplants with DGF are better than in DBD donor kidney transplants experiencing DGF, and similar to outcomes in DCD donor kidney transplants without DGF.

Extracorporeal support: improves donor renal graft function after cardiac death

Donors after cardiac death (DCD) could increase the organ pool. Data supports good long-term renal graft survival. However, DCDs are <10% of deceased donors in the United States, due to delayed graft function, and primary nonfunction. These complications are minimized by extracorporeal support after cardiac death (ECS-DCD). This study assesses immediate and acute renal function from different donor types. DCDs kidneys were recovered by conventional rapid recovery or by ECS, and transplanted into nephrectomized healthy swine. Warm ischemia of 10 and 30 min were evaluated. Swine living donors were controls (LVD). ECS-DCDs were treated with 90 min of perfusion until organ recovery. After procurement, kidneys were cold storage 4-6 h. Renal vascular resistance (RVR), urine output (UO), urine protein concentration (UrPr) and creatinine clearance (CrCl), were collected during 4 h posttransplantation. All grafts functioned with adequate renal blood flow for 4 h. RVR at 4 h posttransplant returned to baseline only in the LVD group (0.36 mmHg/mL/min +/- 0.03). RVR was higher in all DCDs (0.66 mmHg/mL/min +/- 0.13), without differences between them. UO was >50 mL/h in all DCDs, except in DCD-30 (6.8 mL/h +/- 1.7). DCD-30 had lower CrCl (0.9 mL/min +/- 0.2) and higher UrPr >200 mg/dL, compared to other DCDs >10 mL/min and <160 mg/dL, respectively. Normothermic ECS can resuscitate kidneys to transplantable status after 30 min of cardiac arrest/WI.

Time to cardiac death after withdrawal of life-sustaining treatment in potential organ donors

Organ donation after cardiac death (DCD) is increasing markedly, allowing more patients to benefit from transplantation. The time to cardiac death following withdrawal of life-supporting treatment varies widely and is an important determinant of whether organ donation occurs. A prospective multicenter study of potential DCD donors was undertaken to evaluate the time to death and identify associated factors. One hundred and ninety-one potential adult DCD donors at nine UK centers were studied. Treatment withdrawal comprised stopping ventilator support and inotropes. Demographics and physiological variables at the time of death were recorded. Following treatment withdrawal, all potential donors died, with median time to death of 36 min (range 5 min to 3.3 days). Eighty-three potential donors (43.5%) remained alive 1 h after treatment withdrawal, and 69 (36.1%) and 54 (28.3%) at 2 and 4 h, respectively. Univariate analysis revealed that age, cause of death, ventilation mode, inotrope use, systolic blood pressure, FiO2 and arterial pH at treatment withdrawal were all associated with time to death. Multivariable analysis showed that younger age, higher FiO2 and mode of ventilation were independently associated with shorter time to death. This information may aid planning and resourcing of DCD organ recovery and help maximize DCD donor numbers.

The deceased donor score system in kidney transplants from deceased donors after cardiac death

SUMMARY

A clinical score to identify kidneys from donors after cardiac death (DCD) with a high risk of dysfunction following transplantation could be a useful tool to guide the introduction of new algorithms for the preservation of these organs and improve their outcome after transplantation. We investigated whether the deceased donor score (DDS) system could identify DCD kidneys with higher risk of early post-transplant dysfunction. The DDS was validated in a cohort of 168 kidney transplants from donors after brain death (DBD) and then applied to a cohort of 56 kidney transplants from DCD. In the DBD cohort, the DDS grade predicted the incidence of delayed graft function (DGF) and levels of serum creatinine at 3 and 12 months post-transplant. Similarly, in the DCD cohort, the DDS grade correlated with DGF and also predicted the levels of serum creatinine at 3 and 12 months. Interestingly, the DDS identified a subgroup of marginal DCD kidneys in which minimization of cold ischemia time produced better early clinical outcome. These results highlight the impact of early interventions on clinical outcome of marginal DCD kidneys and open the possibility of using the DDS to identify those kidneys that may benefit most from therapeutic interventions before transplantation.

Cardiac recovery in a human non-heart-beating donor after extracorporeal perfusion: source for human heart donation?

Successful renal, liver and more recently lung transplantation using organs from non-heart-beating donors (NHBDs) has been reported. Regarding the heart, it has generally been assumed that warm ischemic insult would result in overwhelming and irreversible myocardial damage. We report recovery of cardiac function in a human NHBD by using extracorporeal perfusion 23 minutes after cardiorespiratory arrest. Successful cardiac resuscitation in the NHBD represents a potential source of increased donor organ supply for clinical heart transplantation.

Donor kidney disease and transplant outcome for kidneys donated after cardiac death

Background

Although outcomes of kidney transplants following donation after cardiac death (DCD) and donation after brainstem death (DBD) are similar, generally only optimal younger DCD donors are considered. This study examined the impact of pre-existing donor kidney disease on the outcome of DCD transplants.

Methods

This retrospective study compared the outcome of all DCD kidney transplants performed during 1996–2006 with contemporaneous kidney transplants from DBD donors. Implantation biopsies were scored for glomerular, tubular, parenchymal and vascular disease (global histology score). There were 104 DCD and 104 DBD kidney transplants.

Results

Delayed graft function (DGF) occurred more frequently in DCD than DBD kidneys (64·4 versus 28·8 per cent; P &lt; 0·001). Long-term graft outcome was similar. The only donor factor that influenced outcome was baseline kidney disease, which was similar in both groups, even though DCD donors were younger, with a higher predonation estimated glomerular filtration rate. The global histology score predicted DGF (odds ratio 1·85 per unit; P = 0·006) and graft failure (relative risk 1·55 per unit; P = 0·001), although there was no difference for DCD and DBD kidneys.

Conclusion

Transplant outcomes for DCD and DBD kidneys are comparable. Baseline donor kidney disease influences DGF and graft survival but the impact is no greater for DCD kidneys.

Outcomes and utilization of kidneys from deceased donors with acute kidney injury

Utilization and long-term outcomes of kidneys from donors with elevated terminal serum creatinine (sCr) levels have not been reported. Using data from the Scientific Registry of Transplant Recipients from 1995 to 2007, recipient outcomes of kidneys from adult donors were evaluated stratified by standard criteria (SCD; n = 82 262) and expanded criteria (ECD; n = 16 978) donor type and by sCr </=1.5, 1.6-2.0 and >2.0 mg/dL. Discard rates for SCDs were ascertained. The relative risk of graft loss was similar for recipients of SCD kidneys with sCr of 1.6-2.0 and >2.0 mg/dL, compared to </=1.5 mg/dL. For ECD recipients, the relative risk of graft failure significantly increased with increasing sCr. Of potential SCDs, the adjusted risk of discard was higher with sCr >2.0 mg/dL (adjusted odds ratio [AOR] 7.04, 95% confidence interval [CI] 6.5-7.6) and 1.6-2.0 mg/dL (AOR 2.7; CI 2.5-2.9) relative to sCr </=1.5 mg/dL. Among potential SCDs, elevated terminal creatinine is a strong independent risk factor for kidney discard; yet, when kidney transplantation is performed elevated donor terminal creatinine is not a risk factor for graft loss. Further research is needed to identify safe practices for the optimal utilization of SCD kidneys from donors with acute kidney injury.

Urological complications and their impact on survival after kidney transplantation from deceased cardiac death donors

Urological complications after kidney transplantation may result in significant morbidity and mortality. However, the incidence of such complications after deceased cardiac death (DCD) donor kidney transplantation and their effect on survival is unknown. Purpose of this study was to estimate the incidence of urological complications after DCD kidney transplantation, and to estimate their impact on survival. Patient records of all 76 DCD kidney transplantations in the period 1997-2004 were reviewed for (urological) complications during the initial hospitalization until 30 days after discharge, and graft survival until the last hospital visit. Urological complications occurred in 32 patients (42.1%), with leakage and/or obstruction occurring in seven patients (9.2%). The latter seems to be comparable with the incidence reported in the literature for deceased heart-beating (DHB) transplantations (range 2.5-10%). Overall graft survival was 92% at 1 year and 88% at 3 years, comparable to the rates reported in the literature for kidneys from DHB donors, and was not affected by urological complications (chi(2) = 0.27, P = 0.61). Only a first warm-ischaemia time of 30 min or more reduced graft survival (chi(2) = 4.38, P < 0.05). We conclude that urological complications occur frequently after DCD kidney transplantation, but do not influence graft survival. The only risk factor for reduced graft survival in DCD transplant recipients was the first warm-ischaemia time.

The marginal liver donor--an update

The number of patients awaiting liver transplantation keeps steadily rising with no corresponding rise in suitable grafts for transplantation. There also is an increasing trend of patients dying or being taken off waiting lists because of deterioration while waiting for a transplant. Over the preceding years the use of marginal grafts in liver transplantation has been driven by the critical shortage of donor organs and by emerging data that their use has resulted in a favourable outcome. This review revisits the factors defining marginality of a graft, and the issues faced by transplant units in making the decision to use such a graft. It also looks at the innovations in transplantation geared towards increasing the donor pool and the resulting issues of matching marginal grafts to suitable recipients.

Non heart-beating donors in England

When transplantation started all organs were retrieved from patients immediately after cardio-respiratory arrest, i.e. from non heart-beating donors. After the recognition that death resulted from irreversible damage to the brainstem, organ retrieval rapidly switched to patients certified dead after brainstem testing. These heart-beating-donors have become the principal source of organs for transplantation for the last 30 years. The number of heart-beating-donors are declining and this is likely to continue, therefore cadaveric organs from non-heart-beating donor offers a large potential of resources for organ transplantation. The aim of this study is to examine clinical outcomes of non-heart-beating donors in the past 10 years in the UK as an way of decreasing pressure in the huge waiting list for organs transplantation.

Outcome of Kidney Transplantation From Nonheart-Beating Versus Heart-Beating Cadaveric Donors

BACKGROUND

This study aimed to assess outcomes of kidney transplants from nonheart-beating (NHB) compared with heart-beating (HB) cadaveric donors with meta-analytical techniques.

METHODS

A literature search was performed for studies comparing kidney transplants from NHB vs. HB cadaveric donors between 1992 and 2005. The following outcomes were evaluated: warm and cold ischemia times, primary nonfunction, delayed graft function, length of hospital stay, acute graft rejection, patient and graft survival, and post-transplant serum creatinine.

RESULTS

Eighteen comparative studies of 114,081 patients matched the selection criteria; 1,858 received kidney from NHB and 112,223 from HB donor. Warm ischemia time was significantly longer for the NHB group by 24 min (P<0.001). Cold ischemia time was similar for the two groups (P=0.97). The incidence of primary nonfunction and delayed graft function was 2.4 times (P<0.001) and 3.6 times (P<0.001) greater, respectively, in the NHB group. Length of hospital stay was longer for the NHB group by 4.6 days (P<0.001). The 6-month, 2-year, and 5-year patient survival were similar between the two groups. The incidence of acute rejection was similar between the two groups whereas the initial graft survival advantage in favor of the HB group diminished gradually over the course of time. There was no statistically significant difference between the two groups for the recipient serum creatinine levels at 3 and 12 months after transplantation.

CONCLUSION

NHB donors carry the potential of expanding the cadaveric kidney pool. Although, transplants from NHB donors are associated with a greater incidence of early adverse events, long-term outcomes appear comparable with those of transplants from HB donors.

Outcomes after transplantation of deceased-donor kidneys with rising serum creatinine

The increasing number of candidates for kidney transplantation and relatively unchanged deceased-donor pool has led to expansion in the criteria for donor acceptability. Outcomes of kidneys from donors with progressively rising creatinine values have not been reported. Patients transplanted between September 2003 and August 2006 with kidneys from donors with peak creatinine levels >2.0 mg/dL were stratified into two groups based on the terminal creatinine and evaluated for outcome: (1) falling creatinine (FC)(n= 27), terminal creatinine at least 0.2mg/dL less than peak, and (2) rising creatinine (RC)(n=24), terminal creatinine = peak. The mean terminal creatinine was significantly higher in the RC group (3.2 +/- 1.3 mg/dL) compared to the FC group (1.9 +/- 0.9 mg/dL)(p<0.0001). Peak creatinine values were similar (RC, 3.2 +/- 1.3; FC, 3.1 +/- 1.3; p=0.6521) between the two groups. Rates of delayed graft function (RC, 24%; FC 32%; p=0.7881) and mean creatinine at follow-up (RC, 1.6 +/- 0.6, FC 1.6 +/- 0.4; p=0.3533) were not significantly different. With a mean follow-up of 287 +/- 274 days, allograft survival was 92% in the RC recipients and 89% in the FC recipients. Under certain conditions, kidneys from donors with rising serum creatinine can be used safely with reasonable early outcomes.

Donation after cardiac death kidneys with low severity pre-arrest acute renal failure

The widening gap between supply and demand for renal transplantation has prompted many centers to use donors after cardiac death. Some of these donors exhibit signs of acute renal failure (ARF) prior to cardiac arrest. Concern has been expressed about poor quality of graft function from such donors. In response to this perception, we reviewed 49 single renal transplant recipients from category III donors after cardiac death between 1998 and 2005, at our center. All kidneys but one had hypothermic machine perfusion and viability testing prior to transplantation. According to the RIFLE criteria, nine recipients had kidneys from donors with "low severity pre-arrest ARF". The remainder of the recipients were used as control group. There was no statistical significant difference in delayed graft function and rejection rates between these two groups. Recipients GFR at 12 months was 44.4 +/- 17.1 and 45.2 +/- 14.7 (mL/min/1.73m(2)) from donors with ARF and without ARF, respectively (p = 0.96). In conclusion, low severity ARF in kidneys from controlled after cardiac death donors can be a reversible condition after transplantation. Short-term results are comparable to the kidneys from same category donors without renal failure, providing that some form of viability assessment is implemented prior to transplantation.

Non-heartbeating donation of kidneys for transplantation

There is a persistent shortage of kidneys available for transplantation. In the early 1980s, therefore, we published the concept of non-heartbeating (NHB) donation; that is, procurement of kidneys from donors whose death has been accompanied by irreversible circulatory arrest. NHB donors are generally categorized using four definitions; category III (awaiting cardiac arrest) and category IV (cardiac arrest while braindead)--or 'controlled'--donors are the most suitable for initiating NHB donation programs. Delayed graft function is associated with use of kidneys from such donors, but has no effect on graft survival in the short or long term. Use of kidneys from category I (dead upon arrival at hospital) and category II (unsuccessfully resuscitated), or 'uncontrolled', donors is likewise associated with delayed graft function, but also with an increased risk of primary nonfunction. Viability testing of donated organs from these sources is a prerequisite for transplantation. Machine preservation parameters and enzyme release measurements help to distinguish viable from nonviable kidneys. The proportion of NHB donor kidneys in the total pool of postmortem kidneys differs considerably between countries. In The Netherlands, the proportion is nearly 50%. This figure is markedly higher than that in the US and Canada, where national programs have now been initiated to increase rates of NHB donation. In the future, warm preservation techniques might facilitate better viability testing, thereby increasing NHB donation from category I and II donors and further reducing the shortage of kidneys available for transplantation.

National recommendations for donation after cardiocirculatory death in Canada: Donation after cardiocirculatory death in Canada

These recommendations are the result of a national, multidisciplinary, year-long process to discuss whether and how to proceed with organ donation after cardiocirculatory death (DCD) in Canada. A national forum was held in February 2005 to discuss and develop recommendations on the principles, procedures and practice related to DCD, including ethical and legal considerations. At the forum's conclusion, a strong majority of participants supported proceeding with DCD programs in Canada. The forum also recognized the need to formulate and emphasize core values to guide the development of programs and protocols based on the medical, ethical and legal framework established at this meeting. Although end-of-life care should routinely include the opportunity to donate organs and tissues, the duty of care toward dying patients and their families remains the dominant priority of health care teams. The complexity and profound implications of death are recognized and should be respected, along with differing personal, ethnocultural and religious perspectives on death and donation. Decisions around withdrawal of life-sustaining therapies, management of the dying process and the determination of death by cardiocirculatory criteria should be separate from and independent of donation and transplant processes. The recommendations in this report are intended to guide individual programs, regional health authorities and jurisdictions in the development of DCD protocols. Programs will develop based on local leadership and advance planning that includes education and engagement of stakeholders, mechanisms to assure safety and quality and public information. We recommend that programs begin with controlled DCD within the intensive care unit where (after a consensual decision to withdraw life-sustaining therapy) death is anticipated, but has not yet occurred, and unhurried consent discussions can be held. Uncontrolled donation (where death has occurred after unanticipated cardiac arrest) should only be considered after a controlled DCD program is well established. Although we recommend that programs commence with kidney donation, regional transplant expertise may guide the inclusion of other organs. The impact of DCD, including pre-and post-mortem interventions, on donor family experiences, organ availability, graft function and recipient survival should be carefully documented and studied.

Are terminally ill patients dying in the ICU suitable for non-heart beating organ donation?

OBJECTIVE

To evaluate the feasibility of implementing a program of controlled non-heart beating organ donation, in patients undergoing the withdrawal of intensive care treatment.

DESIGN AND SETTING

Prospective observational study. Medical and Surgical ICUs in a tertiary university hospital.

PATIENTS

Consecutive patients younger than 70 years dying in the ICU after treatment withdrawal for dire neurological prognosis.

MEASUREMENTS AND RESULTS

We analyzed prospectively collected data from the ICU clinical information system. Seventy-three of 516 ICU deaths (13%) were identified, equally distributed among traumatic, stroke, and anoxic brain injury. The management and the course in these three diagnostic categories were similar. All patients underwent withdrawal of mechanical ventilation and half were extubated. Median time to death was of 4.8 h (IQR 1.4-11.5). In 70% of cases the patient received analgesia and 30% sedation. Such treatment was not related to earlier death. Hypotension was observed in 50% of patients during the 30 min preceding cardiac death.

CONCLUSIONS

With our current management of terminal patients controlled non-heart beating organ procedure may be difficult due to the duration and variability of the dying process. This observation suggests that we can perform better by evaluating this process more closely.

Outcome of nonheart-beating donor kidneys with prolonged delayed graft function after transplantation

Nonheart-beating donor (NHBD) kidneys are frequently associated with delayed graft function (DGF), with a deleterious effect on kidney function and allograft survival. The influence and the duration of DGF on the outcome of NHBD kidneys are assessed. All recipients of an NHBD kidney in the period 1993-2003 were reviewed. Excluded from analysis were patients with primary nonfunction (PNF). One hundred and five patients with a functioning NHBD graft were reviewed: 23 (22%) had immediate function (group 1), 40 (38%) had DGF < or = 2 weeks (group 2), 31 (30%) had DGF 15 days to 4 weeks (group 3) and 11 (10%) had DGF for > 4 weeks (group 4). Creatinine clearance at 3 months was higher in groups 1 and 2 versus group 4 (p = 0.015 and p = 0.006, respectively) and was higher in group 2 versus group 4, at 1 year (p = 0.01). Graft survival was 95%, 98%, 97% and 89%, respectively, at 1 year and 95%, 85%, 77% and 89%, respectively, at 5 years, which was not significantly different. The duration of DGF in NHB kidneys has a negative effect on creatinine clearance, but no effect on graft survival.

Excellent Outcomes after Transplantation of Deceased Donor Kidneys with High Terminal Creatinine and Mild Pathologic Lesions

BACKGROUND

Outcomes after kidney transplantation using deceased donors with high terminal creatinine are not well described but potentially represent an underutilized source of renal allografts. Utility of renal biopsy of these kidneys is similarly not well established.

METHODS

To better understand the posttransplant function of kidneys from donors with high terminal creatinine, we reviewed our database of almost 500 cadaveric kidney transplants. We compared the 65 nonexpanded criteria donors with a final donor creatinine > or = 2.0 mg/dl (range 2.0-4.9 mg/dl) with kidneys procured from donors with terminal creatinine of <1.5. Biopsy results were correlated with graft function.

RESULTS

Kidneys from deceased donors with high terminal creatinine performed as well as kidneys from donors with a normal terminal creatinine with respect to primary non-function, acute rejection, 6-year graft and patient survival, and function over the first 48 months. High creatinine kidneys with moderate or severe lesions on biopsy demonstrated poorer function at 6 months and 1 year as compared to those with mild or no histological lesions.

CONCLUSIONS

Under select conditions, kidneys from donors with high terminal creatinine can be used safely with excellent results.

A 10-year Analysis of Organ Donation after Cardiac Death in the United States

BACKGROUND

The greatest challenge facing transplantation today is how to increase the number of organ donors. Patients with severe brain injury who are not brain-dead can donate organs after they are removed from a ventilator and allowed to die, termed donation after cardiac death (DCD).

METHODS

We analyzed the database of all organs recovered from deceased donors in the United States from 1994 through 2003 to determine DCD trends in the United States. The database was obtained from the United Network for Organ Sharing (UNOS).

RESULTS

There were 57,681 deceased donors reported from 1994 through 2003. Of these, 1,177 were donors without a heartbeat (DWHB), 55,206 were brain dead donors, and 1,298 were unspecified donors. At least one organ was transplanted from 1010 of the 1177 DWHB. Organ procurement organizations (OPOs) reported 0-212 DWHB accounting for up to 12.3 percent of deceased donors. There was a steady annual increase in the number of DWHB, but in 2003 there were still 19 of 59 OPOs that recovered no DWHB. A total of 2,231 organs were transplanted from the 1,177 DWHB donors, and another 665 organs were recovered for transplantation but not transplanted. The transplanted organs included 1,779 kidneys, 395 livers, 54 pancreata, 2 lungs, and 1 heart. Organs from DWHB can be successfully transplanted.

CONCLUSIONS

Wider use of DWHB has the potential to greatly increase the number of organ transplants performed each year in the United States.

Delayed graft function in renal transplantation

PURPOSE OF REVIEW

Delayed graft function is an important determinant of patient and graft survival. A complex of pathologic mechanisms intervenes in the pathophysiology of this outcome. This paper reviews the main processes involved in delayed graft function as they relate to five chronologically related stages: donor tissue quality, brain death and related stress, preservation variables, immune factors, and recipient variables.

RECENT FINDINGS

Dialyzed delayed graft function and nondialyzed slow graft function both have a negative impact on graft survival and on the incidence of acute rejection. Expanded-criteria donors, older donors, and non-heart-beating donors are more frequently used. The long-term results of the use of well-selected non-heart-beating donors are surprisingly good. The process of ischemia/reperfusion injury is already initiated in the brain-death donor and continues during preservation of the graft. Graft-infiltrating T cells, heat shock proteins, and heme oxygenase-1 are implicated in the process. Modifications in immunosuppressive therapy and pharmacologic modulations have an effect on delayed graft function. Delayed graft function plays a part in the incidence of acute rejection, impaired graft function, and survival of patients and grafts.

SUMMARY

This review discusses the current literature on several recent findings of pathophysiologic mechanisms of, and possible therapeutic interventions in, delayed graft function.

Non???Heart-Beating Donor Kidneys in The Netherlands: Allocation and Outcome of Transplantation

BACKGROUND

Since February 1, 2001, kidneys from both heart-beating (HB) and non-heart-beating (NHB) donors in The Netherlands have been indiscriminately allocated through the standard renal-allocation system.

METHODS

Renal function and allograft-survival rate for kidneys from NHB and HB donors were compared at 3 and 12 months.

RESULTS

The outcomes of 276 renal transplants, 176 from HB donors and 100 from NHB III donors, allocated through the standard renal allocation system, Eurotransplant Kidney Allocation System, and performed between February 1, 2001 and March 1, 2002 were compared. Three months after transplantation, graft survival was 93.7% for HB kidneys and 85.0% for NHB kidneys (P<0.05). At 12 months, graft survival was 92.0% and 83.0%, respectively (P<0.03). Serum creatinine levels in the two groups were comparable at both 3 and 12 months. Multivariate analysis identified previous kidney transplantation (relative risk [RR] 3.33; P<0.005), donor creatinine (RR 1.01; P<0.005), and NHB (RR 2.38; P<0.05) as independent risk factors for transplant failure within 12 months. In multivariate analysis of NHB data, a warm ischemia time (WIT) of 30 minutes or longer (P<0.005; RR 6.16, 95% confidence interval 2.11-18.00) was associated with early graft failure. No difference in 12-month graft survival was seen between HB and NHB kidneys after excluding the kidneys that failed in the first 3 months.

CONCLUSION

Early graft failure was significantly more likely in recipients of kidneys from NHB donors. A prolonged WIT was strongly associated with this failure. Standard allocation procedures do not have a negative effect on outcome, and there is no reason to allocate NHB kidneys differently from HB kidneys.

Non-heart-beating donation: ten evidence-based ethical recommendations

The renewed interest in non-heart-beating donation (NHBD) in the past decade has resulted in renewed examination of the concept and meaning of death; of the nature of consent; of the propriety of interventions for the benefit of the recipient and not the donor; of potential conflicts of interest; and of defining futility. There is recognition of the need to maintain public trust. Recent experience indicates that NHBD could make a significant contribution to total renal transplant numbers. While there is graft dysfunction in the short term, the long-term results are comparable to those of transplants from heart-beating kidney donors, and in one series, even to living donors. The University of Zurich's experience indicates that waiting 10 minutes after asystole and not using in situ cooling do not adversely affect long-term outcomes. NHBD under ideal conditions could be extended to other organs such as the liver and pancreas. Ethical concerns are not insurmountable and can be minimized if cooling procedures and the use of drugs, such as heparin and phentolamine, is minimized, and if a period of 10 minutes is allowed to elapse after asystole before death is declared. We make a series of evidence-based recommendations for protocol development.