Expansion of the kidney donor pool by using cardiac death donors with prolonged time to cardiorespiratory arrest

Standardized deceased donor kidney donation rates in the UK reveal marked regional variation and highlight the potential for increasing kidney donation: a prospective cohort study†

Background

The UK has implemented a national strategy for organ donation that includes a centrally coordinated network of specialist nurses in organ donation embedded in all intensive care units and a national organ retrieval service for deceased organ donors. We aimed to determine whether despite the national approach to donation there is significant regional variation in deceased donor kidney donation rates.

Methods

The UK prospective audit of deaths in critical care was analysed for a cohort of patients who died in critical care between April 2010 and December 2011. Multivariate logistic regression was used to identify the factors associated with kidney donation. The logistic regression model was then used to produce risk-adjusted funnel plots describing the regional variation in donation rates.

Results

Of the 27 482 patients who died in a critical care setting, 1528 (5.5%) became kidney donors. Factors found to influence donation rates significantly were: type of critical care [e.g. neurointensive vs general intensive care: OR 1.53, 95% confidence interval (CI) 1.34–1.75, P<0.0001], patient ethnicity (e.g. ‘Asian’ vs ‘white’: OR 0.17, 95% CI 0.11–0.26, P<0.0001), age (e.g. age >69 vs age 18–39 yr: OR 0.2, 0.15–0.25, P<0.0001), and cause of death [e.g. ‘other’ (excluding ‘stroke’ and ‘trauma’) vs ‘trauma’: OR 0.04, 95% CI 0.03–0.05, P<0.0001]. Despite correction for these variables, kidney donation rates for the 20 UK kidney donor regions showed marked variation. The overall standardized donation rate ranged from 3.2 to 7.5%. Four regions had donation rates of >2 standard deviations (sd) from the mean (two below and two above). Regional variation was most marked for donation after circulatory death (DCD) kidney donors with 9 of the 20 regions demonstrating donation rates of >2 sd from the mean (5 below and 4 above).

Conclusions

The marked regional variation in kidney donation rates observed in this cohort after adjustment for factors strongly associated with donation rates suggests that there is considerable scope for further increasing kidney donation rates in the UK, particularly DCD.

Uncontrolled donors with controlled reperfusion after sixty minutes of asystole: a novel reliable resource for kidney transplantation

BACKGROUND

Organ shortage leads to usage of kidneys from donors after sudden cardiac death, or uncontrolled donors (UDCD). Ischemic injury due to cessation of circulation remains a crucial problem that limits adoption of UDCD. Our clinical investigation was to determine the applicability of kidneys obtained from UDCD and resuscitated by extracorporeal perfusion in situ after 60 minutes of asystole.

METHODS

In 2009-2011, organ procurement service of St. Petersburg, obtained kidneys from 22 UDCD with critically expanded warm ischemic time (WIT). No patients were considered as potential organ donors initially. All donors died after sudden irreversible cardiac arrest. Mean WIT was 61.4±4.5 minutes. For kidney resuscitation, the subnormothermic extracorporeal abdominal perfusion with thrombolytics and leukocyte depletion was employed. Grafts were transplanted into 44 recipients. The outcomes of transplantation of resuscitated kidneys were compared to outcomes of 87 KTx from 74 brain death donors (BDDs).

RESULTS

Immediate functioning of kidney grafts was observed in 21 of the 44 recipients, with no cases of primary non function. By the end of the first post-transplant year there was an acute rejection rate of 9.1% (4 episodes of rejection) in the UDCD group versus 14.2% (13 episodes of rejection) in the BDD group. The actual 1-year graft survival rate was 95.5% (n = 42) in UDCD group, and 94.6% (n = 87) in BDD group. Creatinine levels at the end of the first year were 0.116±0.008 and 0.115±0.004 mmol/l in UDCD and BDD groups, respectively.

CONCLUSIONS

UDCD kidneys with critically expanded WIT could be succefully used for transplantation if in situ organ "resuscitation" perfusion is included into procurement protocol. The results of 1-year follow-up meet the generally accepted criteria for graft survival and function. In situ reperfusion may exert a therapeutic effect on grafts before procurement. This approach could substantially expand the organ donors' pool.

No-touch time in donors after cardiac death (nonheart-beating organ donation)

PURPOSE OF REVIEW

To evaluate arterial pulselessness and the no-touch time of 5 min in defining irreversible cessation of cardiorespiratory functions in nonheart-beating donation (NHBD).

RECENT FINDINGS

Experimental NHBD studies identified compensatory neurohumoral mechanisms elicited in controlled terminal shock after withdrawal of life support. The neurohumoral mechanisms can preserve the viability of the cardiovascular and central nervous systems by: 1) diverting systemic blood flow from nonvital to vital organs; and 2) maintaining the perfusion pressure (arterial to venous pressure gradient minus interstitial tissue pressure) and microcirculation in vital organs. These compensatory mechanisms cause an early onset of splanchnic hypoperfusion and antemortem ischaemia of transplantable organs and preclude irreversible cessation of cardiorespiratory functions after brief periods of circulatory arrest. Allograft ischaemia is associated with primary nonfunction or delayed function in transplant recipients similar in aetiology to organ dysfunction in the postresuscitation phase of shock.

SUMMARY

In-situ perfusion can reverse ceased cardiac and neurological functions after arterial pulselessness and a no-touch time of 5 min in experimental models. Perfusion pressures are superior to arterial pulselessness in determining reversibility of ceased cardiac and neurological functions in circulatory arrest. Utilizing physiologically relevant circulatory and neurological parameters in NHBD protocols is essential for ascertaining irreversible cessation of vital functions in donors.

Time to death after withdrawal of treatment in donation after circulatory death (DCD) donors

PURPOSE

Controlled donation after circulatory death (DCD) donors make an important contribution to organ transplantation but there is considerable scope for further increasing the conversion of potential to actual DCD organ donors. The period between withdrawal of life-supporting treatment and death (the withdrawal period) is a major determinant of whether organ donation proceeds and it is therefore timely to review recent relevant studies in this area.

RECENT FINDINGS

The duration and haemodynamic nature of the withdrawal period is extremely variable, and clinical guidelines for management of the potential donor during this period differ widely. Recent evidence suggests that kidneys from DCD donors with a prolonged withdrawal period can be used to increase the number of transplants performed and provide satisfactory graft function, suggesting that it is not the duration but the haemodynamic profile of the donor during this phase that are important. This suggestion questions the relevance of clinical indices predicting death within 1 h of treatment withdrawal.

SUMMARY

Future studies should aim to define clinical and physiological variables during the withdrawal period that can be used to maximize well tolerated use of organs from potential DCD donors; these thresholds are likely to differ according to organ type.

Improvements in kidney transplantation from donors after cardiac death

To reduce the growing waiting list for kidney transplantation, we explored the limits of kidney transplantation from donors after cardiac death by liberally accepting marginal donor kidneys for transplantation. As the percentage of primary non-function (PNF) increased, we evaluated our transplantation program and implemented changes to reduce the high percentage of PNF in 2005, followed by a second evaluation over the period 2006-2009. Recipients of a kidney from a donor after cardiac death between 1998 and 2005 were analyzed, with PNF as outcome measure. During the period 2002-2005, the percentage of PNF increased and crossed the upper control limits of 12% which was considered as unacceptably high. After implementation of changes, this percentage was reduced to 5%, without changing the number of kidney transplantations from donors after cardiac death. Continuous monitoring of the quality of care is essential as the boundaries of organ donation and transplantation are sought. Meticulous donor, preservation, and recipient management make extension of the donor potential possible, with good results for the individual recipient. Liberal use of kidneys from donors after cardiac death may contribute to a reduction in the waiting list for kidney transplantation and dialysis associated mortality.

Asystole to cross-clamp period predicts development of biliary complications in liver transplantation using donation after cardiac death donors

This study sought to determine the procurement factors that lead to development of intrahepatic bile duct strictures (ITBS) and overall biliary complications in recipients of donation after cardiac death (DCD) liver grafts. Detailed information for different time points during procurement (withdrawal of support; SBP < 50 mmHg; oxygen saturation <30%; mandatory wait period; asystole; incision; aortic cross clamp) and their association with the development of ITBS and overall biliary complications were examined using logistic regression. Two hundred and fifteen liver transplants using DCD donors were performed between 1998 and 2010 at Mayo Clinic Florida. Of all the time periods during procurement, only asystole-cross clamp period was significantly different between patients with ITBS versus no ITBS (P = 0.048) and between the patients who had overall biliary complications versus no biliary complications (P = 0.047). On multivariate analysis, only asystole-cross clamp period was significant predictor for development of ITBS (P = 0.015) and development of overall biliary complications (P = 0.029). Hemodynamic changes in the agonal period did not emerge as risk factors. The results of the study raise the possibility of utilizing asystole-cross-clamp period in place of or in conjunction with donor warm ischemia time in determining viability or quality of liver grafts.

Kidney donation after cardiac death

There is continuing disparity between demand for and supply of kidneys for transplantation. This review describes the current state of kidney donation after cardiac death (DCD) and provides recommendations for a way forward. The conversion rate for potential DCD donors varies from 40%-80%. Compared to controlled DCD, uncontrolled DCD is more labour intensive, has a lower conversion rate and a higher discard rate. The super-rapid laparotomy technique involving direct aortic cannulation is preferred over in situ perfusion in controlled DCD donation and is associated with lower kidney discard rates, shorter warm ischaemia times and higher graft survival rates. DCD kidneys showed a 5.73-fold increase in the incidence of delayed graft function (DGF) and a higher primary non function rate compared to donation after brain death kidneys, but the long term graft function is equivalent between the two. The cold ischaemia time is a controllable factor that significantly influences the outcome of allografts, for example, limiting it to < 12 h markedly reduces DGF. DCD kidneys from donors < 50 function like standard criteria kidneys and should be viewed as such. As the majority of DCD kidneys are from controlled donation, incorporation of uncontrolled donation will expand the donor pool. Efforts to maximise the supply of kidneys from DCD include: implementing organ recovery from emergency department setting; improving family consent rate; utilising technological developments to optimise organs either prior to recovery from donors or during storage; improving organ allocation to ensure best utility; and improving viability testing to reduce primary non function.

Comparison of liver transplantation outcomes from adult split liver and circulatory death donors

BACKGROUND

Adult whole-organ donation after circulatory death (DCD) and 'split' extended right lobe donation after brain death (ERL-DBD) liver transplants are considered marginal, but direct comparison of outcomes has rarely been performed. Such a comparison may rationalize the use of DCD livers, which varies widely between UK centres.

METHODS

Outcomes for adult ERL-DBD livers and 'controlled' DCD liver transplantations performed at the Cambridge Transplant Centre between January 2004 and December 2010 were compared retrospectively.

RESULTS

None of the 32 patients in the DCD cohort suffered early graft failure, compared with five of 17 in the ERL-DBD cohort. Reasons for graft failure were hepatic artery thrombosis (3), progressive cholestasis (1) and small-for-size syndrome (1). Early allograft dysfunction occurred in a further five patients in each group. In the DCD group, ischaemic cholangiopathy developed in six patients, resulting in graft failure within the first year in two; the others remained stable. The incidence of biliary anastomotic complications was similar in both groups. Kaplan-Meier survival analysis confirmed superior graft survival in the DCD liver group (93 per cent at 3 years versus 71 per cent in the ERL-DBD cohort; P = 0·047), comparable to that of contemporaneous whole DBD liver transplants (93 per cent at 3 years). Patient survival was similar in all groups.

CONCLUSION

Graft outcomes of DCD liver transplants were better than those of ERL-DBD liver transplants. Redefining DCD liver criteria and refining donor-recipient selection for ERL-DBD transplants should be further explored.

Prediction of potential for organ donation after cardiac death in patients in neurocritical state: a prospective observational study

BACKGROUND

Successful donation of organs after cardiac death (DCD) requires identification of patients who will die within 60 min of withdrawal of life-sustaining treatment (WLST). We aimed to validate a straightforward model to predict the likelihood of death within 60 min of WLST in patients with irreversible brain injury.

METHODS

In this multicentre, observational study, we prospectively enrolled consecutive comatose patients with irreversible brain injury undergoing WLST at six medical centres in the USA and the Netherlands. We assessed four clinical characteristics (corneal reflex, cough reflex, best motor response, and oxygenation index) as predictor variables, which were selected on the basis of previous findings. We excluded patients who had brain death or were not intubated. The primary endpoint was death within 60 min of WLST. We used univariate and multivariable logistic regression analyses to assess associations with predictor variables. Points attributed to each variable were summed to create a predictive score for cardiac death in patients in neurocritical state (the DCD-N score). We assessed performance of the score using area under the curve analysis.

FINDINGS

We included 178 patients, 82 (46%) of whom died within 60 min of WLST. Absent corneal reflexes (odds ratio [OR] 2·67, 95% CI 1·19-6·01; p=0·0173; 1 point), absent cough reflex (4·16, 1·79-9·70; p=0·0009; 2 points), extensor or absent motor responses (2·99, 1·22-7·34; p=0·0168; 1 point), and an oxygenation index score of more than 3·0 (2·31, 1·10-4·88; p=0·0276; 1 point) were predictive of death within 60 min of WLST. 59 of 82 patients who died within 60 min of WLST had DCD-N scores of 3 or more (72% sensitivity), and 75 of 96 of those who did not die within this interval had scores of 0-2 (78% specificity); taking into account the prevalence of death within 60 min in this population, a score of 3 or more was translated into a 74% chance of death within 60 min (positive predictive value) and a score of 0-2 translated into a 77% chance of survival beyond 60 min (negative predictive value).

INTERPRETATION

The DCD-N score can be used to predict potential candidates for DCD in patients with non-survivable brain injury. However, this score needs to be tested specifically in a cohort of potential donors participating in DCD protocols.

FUNDING

None.

Kidney damage during organ recovery in donation after circulatory death donors: data from UK National Transplant Database

During the last 10 years, kidneys recovered/transplanted from donors after circulatory death (DCD) have significantly increased. To optimize their use, there has been an urgent need to minimize both warm and cold ischemia, which often necessitates more rapid removal. To compare the rates of kidney injury during procurement from DCD and donors after brain death (DBD) organ donors. A total of 13 260 kidney procurements were performed in the United Kingdom over a 10-year period (2000-2010). Injuries occurred in 903 procedures (7.1%). Twelve thousand three hundred seventy-two (93.3%) kidneys were recovered from DBD donors and 888 (6.7%) from DCD donors. The rates of kidney injury were significantly higher when recovered from DCD donors (11.4% vs. 6.8%, p < 0.001). Capsular, ureteric and vascular injuries were all significantly more frequent (p = 0.002, p < 0.001 and p = 0.017, respectively). Discard because of injury was more common after DCD donation (p = 0.002). Multivariate analysis demonstrated procurement injuries were significantly associated with DCD donors (p = 0.035) and increased donor age (<0.001) and donor body mass index (BMI; 0.001), donor male gender (p = 0.001) and no liver donation (0.009). We conclude that procurement from DCD donors leads to higher rates of injury to the kidney and are more likely to be discarded.

Outcomes of simultaneous pancreas-kidney transplantation from brain-dead and controlled circulatory death donors

BACKGROUND

Organ scarcity has prompted increased use of organs from donation after circulatory death (DCD) donors. An early single-centre experience of simultaneous pancreas-kidney (SPK) transplantation from controlled DCD donors is described here.

METHODS

Outcomes of SPK transplants from DCD and donation after brain death (DBD) donors between August 2008 and January 2011 were reviewed retrospectively.

RESULTS

SPK transplants from 20 DCD and 40 DBD donors were carried out. Donor and recipient characteristics were similar for both groups, although pancreas cold ischaemia times were shorter in DCD recipients: median (range) 8·2 (5·9-10·5) versus 9·5 (3·8-12·5) h respectively (P = 0·004). Median time from treatment withdrawal to cold perfusion was 24 (range 16-110) min for DCD donors. There were no episodes of delayed pancreatic graft function in either group; the graft thrombosis rates were both 5 per cent. Similarly, there were no differences in haemoglobin A1c level at 12 months: median (range) 5·4 (4·9-7·7) per cent in DCD group versus 5·4 (4·1-6·2) per cent in DBD group (P = 0·910). Pancreas graft survival rates were not significantly different, with Kaplan-Meier 1-year survival estimates of 84 and 95 per cent respectively (P = 0·181).

CONCLUSION

DCD SPK grafts had comparable short-term outcomes to DBD grafts, even when procured from selected donors with a prolonged agonal phase.

Donation after circulatory death

Donation after circulatory death (DCD) describes the retrieval of organs for the purposes of transplantation that follows death confirmed using circulatory criteria. The persisting shortfall in the availability of organs for transplantation has prompted many countries to re-introduce DCD schemes not only for kidney retrieval but increasingly for other organs with a lower tolerance for warm ischaemia such as the liver, pancreas, and lungs. DCD contrasts in many important respects to the current standard model for deceased donation, namely donation after brain death. The challenge in the practice of DCD includes how to identify patients as suitable potential DCD donors, how to support and maintain the trust of bereaved families, and how to manage the consequences of warm ischaemia in a fashion that is professionally, ethically, and legally acceptable. Many of the concerns about the practice of both controlled and uncontrolled DCD are being addressed by increasing professional consensus on the ethical and legal justification for many of the interventions necessary to facilitate DCD. In some countries, DCD after the withdrawal of active treatment accounts for a substantial proportion of deceased organ donors overall. Where this occurs, there is an increased acceptance that organ and tissue donation should be considered a routine part of end-of-life care in both intensive care unit and emergency department.

Termination of resuscitation of nontraumatic cardiopulmonary arrest: resource document for the National Association of EMS Physicians position statement

In the development of an emergency medical services (EMS) system, medical directors should consider the implementation of protocols for the termination of resuscitation (TOR) of nontraumatic cardiopulmonary arrest. Such protocols have the potential to decrease unnecessary use of warning lights and sirens and save valuable public health resources. Termination-of-resuscitation protocols for nontraumatic cardiopulmonary arrest should be based on the determination that an EMS provider did not witness the arrest, there is no shockable rhythm identified, and there is no return of spontaneous circulation (ROSC) prior to EMS transport. Further research is needed to determine the need for direct medical oversight in TOR protocols and the duration of resuscitation prior to EMS providers' determining that ROSC will not be achieved. This paper is the resource document to the National Association of EMS Physicians position statement on the termination of resuscitation for nontraumatic cardiopulmonary arrest.