Introduction

What are non-heart beating donors or cardiac dead donors?

The first terminology used for these donors was “Non-heart beating donor” to differentiate it from brain dead donor where the heart is still beating. This was later disregarded to include death in the terminology and replaced by “Donation after cardiac death” in contrast to “Donation after brain death” but with further progress and reports of cardiac transplantation after donation after cardiac death, the terminology has now been changed to “Donation after circulatory death” (DCD) to reflect the correct status of heart which can still be viable and used. Before the introduction of legislation defining brainstem death in the 1970s, all deceased donor transplants were performed using non-heart beating donors. The conventional brain dead donors have lost all brain function, but blood still circulates to the other organs providing sufficient time to organise organ donation. On the other hand, the non-heart beating donors have suffered circulatory death with the heart no longer pumping blood to the organs. In this situation, organ retrieval has to start as soon as possible after death has been determined and preferably within the next 60 minutes. There are two broad categories of non-heart beating donors according to the circumstances of cardiac arrest –

1. Uncontrolled – Where cardiac arrest occurs suddenly and is unexpected. The time taken to retrieve organs and put them in ice (Warm ischaemic time) from these uncontrolled non-heart beating donors is much longer.
2. Controlled – Where elective withdrawal of ventilation in an end of life situation leads to cardiac arrest. The warm ischemia time in these donors is much less and can be controlled, therefore are better suited for this type of donation.

Whereas a few countries like Spain, France, Italy use organs from uncontrolled donors, controlled donation has been mainly used to increase donor pool worldwide and contributes up to 10 donations per million population in countries like Netherlands, UK. In the Indian context, we are yet to reach a donation rate of 1 per million population from brain dead donors.

There are a few reasons for increase in donation after cardiac death across the globe.

1. Improved intensive and neurosurgical care now prevents brain death in devastating brain injuries as the brain is decompressed by craniotomy/craniectomy.
2. Wider acceptance of futility of continuing care in end of life situations where a decision is taken to withdraw life support in terminally ill patient. The decision to donate organs is then taken after the family and treating physician have accepted withdrawal of care. 
3. Limited availability of critical care beds, avoidable expense associated with critical care of terminally ill patient are other factors favouring withdrawal of life support in these situations. In developed countries, patients themselves have an advance directive as to what to do when faced with irrecoverable end of life situation.

Our experience

We performed our 1st donation from a DCD patient in 2011 who was 51 yrs female with terminal interstitial lung disease and her family decided against further treatment and approached us for organ donation. She had a cardiac arrest in ICU and was immediately shifted to OT, which was kept ready and kidneys retrieved. The total warm ischemia was 90 min. Unfortunately, one of these kidneys never functioned and the second had suboptimal function with the best creatinine of 2.3 mg%. It made us realise that it is not possible to retrieve organs within the limits of 60 minutes of warm ischemia in our setup and some form of organ preservation is necessary during this period. No further donation took place for the next three years in view of the poor outcomes. In 2014, the family of a 22 yr old potentially brain dead donor had consented for organ donation, but could not be declared brain dead as brain death certification committee wanted correction of electrolytes (Na 180, K 2.3). He had a cardiac arrest and this time, the ICU team was advised to continue CPR till operation theatre could be arranged. With a total manual CPR of 65 minutes, we could retrieve organs with a warm ischemia of 80 minutes. One of the two recipients backed out after second thoughts considering the outcome of first donation. The recipient who underwent transplant had a prolonged DGF for 4 weeks, but eventually recovered normal kidney function and still maintains a current creatinine of 0.9 mg% after 3 years of transplant. Another two donations were done in the next year, one without CPR and one with manual CPR and it was realised that the outcomes were better if CPR was continued. Later on, an automated CPR machine was bought which continues to be used for these cases at our hospital till now. The donors underwent rapid iliac artery cannulation with infusion of preservative cold solution and immediate surface cooling of organs during retrieval surgery. Prior femoral cannulation was not used in any patient. Finally we could procure double balloon catheter which is another asset in this situation as cooling of organs could be greatly expedited with its use thereby reducing warm ischemia time. 9 such donors had kidneys retrieved after cardiac arrest so far at PGI Chandigarh. Only in one such donor, kidneys could not be utilised due to prolonged warm ischemia.

Outcomes of patients who have undergone transplantation from DCD donors

There are a number of challenges in DCD. Whether it is ethically justified to withdraw life support for obtaining organs? It is amply clear that decision to withdraw support has to be separate from organ donation and only when decision to withdraw support has been taken by the family and the physician, the talk about organ donation starts. There are issues about when and where to withdraw life support. In some countries, life support is withdrawn inside the operation theatre whereas in others, it is done in a separate room close to the theatre in presence of family members. Whereas withdrawal in theatre limits warm ischemia, it is not the best solution ethically speaking. How long should one wait with asystole to declare death? The time has ranged from 2 – 10 minutes across different countries, but 5 minutes is probably a wider accepted time. Whether one should do any antemortem interventions like prior femoral cannulation to reduce ischemic injury to organs is also a subject of ethical dilemma.

In India, the biggest challenge to DCD donation is lack of clarity in law and there is no practice of withdrawal of life support in end of life situation, thereby limiting this mode of donation. Moreover, there is no mention of use of organs after circulatory death in the THOA 1994 and its subsequent modifications. Therefore, it can only be used in unanticipated circulatory arrests where there are more challenges in terms of doing transplantation on emergency basis. That’s the reason for surgeons being reluctant to go ahead with this form of donation in the country especially when recovery times for the recipients is also likely to be much delayed. But 5-10% of brain dead donors do suffer from cardiac arrest before organ retrieval can take place and in most centres, these organs go waste. These are the donors where we stepped in and utilised their organs with good outcomes. These formed nearly 10% (13/128) of our deceased donor transplants since we regularly started this activity. In our country, we are likely to touch 1000 donations per year quite soon and even a 5% addition to this pool would mean 100 additional kidney transplants every year.

The long term outcomes after DCD kidney transplants is similar to transplants done from brain dead donors with 74% 10 year-graft survival in patients undergoing their first kidney transplants from these donors. That is the reason it is increasing worldwide in view of ever increasing demand for organs. Further progress in storage techniques like Warm perfusion and ECMO for resuscitation may provide further impetus to this form of organ donation.

Summary

Kidneys from donors after cardiac arrest can serve as a useful adjunct in deceased donor programme. Strategies to limit ischemic damage to organs should be used. A good infrastructure and on call support is required to successfully run this programme. Newer preservation and viability assessment methods for organs may change the dynamics in the near future. However, withdrawal of care guidelines for terminally ill patients is desperately required in our country for promoting DCD. These guidelines would also provide a dignity of death in an end of life situation and not keep these individuals in an ICU on a ventilator for an extended period.