24.1 Introduction
Organ donation is considered the “gift of life” as a person donates one or more of their organs to people in need of those. Organ donation happens either after confirmation of death (with the assent of the next of kin) or while the person is alive (after obtaining consent).
For obvious reasons, living donation is limited either to one kidney only or part of the liver. Living donation can be directed (to someone we know, related or not) or non-directed altruistic when a living person anonymously donates one of their kidneys to a person they don’t know. Sometimes, if a person is not a direct “match” for someone they wish to donate, they can donate to someone else, and another person can donate to their intended recipient. This is called paired/pooled donation and is part of the UK Living Kidney Sharing Schemes.
This chapter will focus on deceased donation practices and processes as they take place in intensive care units around the world after confirmation of death. Unfortunately, the need for organs for transplantation is greater than the number of the organs donated, resulting in people dying or experiencing poor quality of life while waiting for a transplant. For this reason, the interest of governments and professional medical bodies has increased in the last ten years. The aim is to make each country self-sufficient in donation and transplantation.
24.2 The “Dead Donor Rule”
The ethical platform of deceased organ donation is based on the “dead donor rule” which supports vital organs to be taken only from persons who are declared dead.
Donation from deceased persons. Absolute numbers and rates (per million of population of actual deceased donors in 2015). *Data of the WHO-ONT Global Observatory on Donation and Transplantation (2015)
Number of deceased donors and transplants in the UK, 1 April 2007–31 March 2017 and patients on the active transplant list on 31st March. Source: Transplant activity in the UK, NHS Blood and Transplant. https://www.odt.nhs.uk/statistics-and-reports/
24.3 Donation After Brainstem or Brain Death
Although the incentive of diagnosing death using neurological criteria was derived by the need for defining futility in cases that the damage of the brain is irreversible, it allows organ donation to take place before apnea results in cardiac arrest. This organ donation pathway is described as “donation after brain death” or “DBD” or “heart-beating donation”. Compared to donation after circulatory death, it offers the opportunity to retrieve more organs (average DBD 3.7 vs DCD 2.8 organs/donor).
The organs that can be retrieved under these circumstances are kidneys (2), liver, heart, lungs (2), pancreas and small intestine. This means that there is the opportunity for eight different life-changing or lifesaving transplants. However, the physiological changes that occur during brain death present us with challenges to maintain the function of these organs.
24.3.1 Donor Optimization
The neuroprotective therapeutic goals in patients with devastating neurological injuries are sometimes harmful to other organs. Brain death is followed by a cascade of physiological changes that include catecholamine surge, myocardial injury, hormonal depletion, hypovolemia, cardiovascular instability, neurogenic pulmonary oedema and clotting abnormalities. In addition, very often, the injury is a result of trauma not necessarily isolated to the brain with injuries to the lungs and myocardium or injuries that cause excessive blood loss. This creates very challenging physiological conditions for the physician who aims to maintain the function of vital organs.
Different organizations worldwide have tried to standardize pathways of treatment for these donors. Although there is still a considerable variation of management but also of application of these protocols, the aims and physiological goals are similar.
Ethically, these interventions are supported on the basis that consent (via family’s permission) for organ donation has been given and it is for patient’s best overall interest to reach a successful donation.
The fundamental principles of organ donor management are based on the same monitoring and therapeutic tenets used in intensive care units worldwide when caring for the critically ill patient. Effectively after confirmation of brain death, a therapeutic focus shift from neuroprotective to organ physiology restoration is required.
These donors should be looked after in an intensive care environment, where the nursing and medical care needs and support to the relatives can be facilitated.
The use of lung protective ventilation is advocated, with the use of tidal volumes 6–8 ml/kg of predicted body weight, ideal PEEP, the use of closed circuit for airway suction, apnea tests to be performed by using continuous positive airway pressure (CPAP) and recruitment manoeuvres. These simple management changes can increase lung procurement rates by 20%.
Cardiovascular management aims to achieve normovolemia with correction of hypovolemia and treatment of diabetes insipidus (DI) while avoiding excessive fluid administration at the same time. Unfortunately, these patients may have suffered a myocardial injury at the same time, and this combination makes their management a delicate balancing act. The minimum monitoring that is recommended is invasive arterial blood pressure measurement, central venous pressure measurement and hourly urine output. Most of the intensive care units though will try to optimize the cardiovascular system with the guidance of flow monitoring (invasive or non-invasive). The use of inotropes and vasopressors is common. Introduction of vasopressin and weaning of epinephrine or norepinephrine is advised. Hypernatremia is usually the manifestation of excessive free water loss and hypovolemia (DI) and should be avoided and corrected as it affects the survival of the transplanted liver graft.
Replacement of hormonal deficiencies will help to achieve homeostasis. Initial DI management may include the use of DDAVP. Insulin infusions and maintenance of glucose source are advocated. There is support for the use of methylprednisolone 15 mg/kg (max dose 1 g) every 12 h to attenuate the systemic inflammation of brain death by many organizations. Temperature >35 °C is also recommended.
Donor optimisation extended care bundle. Source: NHS blood and transplant, UK. https://www.odt.nhs.uk/deceased-donation/best-practice-guidance/donation-after-brainstem-death
24.4 Donation After Circulatory Death
Worldwide DCD donor numbers (2013). Source: International Registry in Organ Donation and Transplantation (IRODaT), Free Database, http://www.irodat.org. Used with permission
The modified Maastricht classification for donors after circulatory death—Paris 2013
Uncontrolled | Category I | Found dead and have not been resuscitated Ia: out-of-hospital Ib: in-hospital |
Uncontrolled | Category II | Unexpected cardiac arrest—unsuccessful resuscitation IIa out-of-hospital IIb in-hospital |
Controlled | Category III | Awaiting cardiac arrest after withdrawal of life-sustaining therapy/support |
Controlled | Category IV | Cardiac arrest while brain dead IVa unexpected circulatory arrest in a brain-dead donor (uncontrolled) IVb expected circulatory arrest in a brain-dead donor (highly controlled) |
Controlled | Category V | Euthanasia (only in countries that legislation allows) Va Medically assisted circulatory death in ICU Vb Medically assisted circulatory death in operating theatre |
Although DCD programs continue to increase the numbers of donors, clinicians in intensive care units are faced with challenges such as identification of potential donors, perceived conflicts between the decision to withdraw life-sustaining therapy (WLST) and DCD donation, safe diagnosis of death using cardiorespiratory criteria and ethical challenges around delayed WLST, to name few.
24.4.1 Confirmation of Death Following Cessation of Cardiorespiratory Function
Although brain death has generated a lot of controversy over the years, confirming death using cardiorespiratory criteria, it is not without challenges, and Lazarus phenomena have been reported after incorrect confirmation of death.
The accurate confirmation of death is crucial in cases that will proceed to organ donation as all donors should follow the “dead donor rule”. Since death is a process that affects different organs at different timeframes, clinicians have to decide when the irreversible loss of life has occurred.
In most countries, absent arterial pulse, absent heart sounds, apnea and unresponsiveness are recommended as criteria to confirm death. The observation period varies worldwide ranging from 2 to 10 min with most common the 5-min period. In the UK, the confirmation of death can be made only if there is “absence of pupillary responses to light, of corneal reflexes and any motor response to supraorbital pressure”, 5 min after continuous observation of cardiorespiratory arrest.
24.4.2 Warm Ischaemic Time
As the cardiovascular system collapses, during the dying process, the organs of DCD donors are exposed to longer warm ischaemic times than the organs retrieved from DBD donors. This phase starts before the asystole when the systolic blood pressure drops below 50 mmHg, or the arterial oxygen saturation decreases below 70% and stops when the retrieval teams initiate cold perfusion. This ischaemic injury increases primary and delayed graft function of the organs retrieved with liver (ischaemic cholangiopathy) and pancreas being more vulnerable.
Withdrawal of treatment in the operating theatre suite
Timely confirmation of death
Normothermic regional perfusion (NRP)
24.4.3 Heart and Lung DCD Donation
Although the most significant contribution of DCD programs is to kidney transplantation, there are successful efforts to increase lung retrievals and recently heart procurement.
DCD lungs have not been exposed to the catecholamine storm during brain death or the excessive fluid administration that is usually observed in DBD donors. For successful lung donation after death confirmed using cardiorespiratory criteria, protection of the airway to prevent aspiration and early inflation of the lungs with oxygen is required. Since it is inappropriate to initiate any cardiopulmonary resuscitation after death has confirmed, strict adherence to protocols is paramount. In summary, there should be only one inflation manoeuvre of the lungs after a minimum of 10-min observation of circulatory arrest.
Although the first heart transplant by Barnard and colleagues was from a DCD donor, since the neurological criteria for confirming death were adopted, the primary source of transplanted hearts are the DBD donors. In 2008, surgeons from Denver, USA published a series of 3 heart transplants in infants from DCD donors. The 6-month survival was 100%. In 2014, the first adult series of successful DCD heart transplantation was published by an Australian group. The importance of this was that the donors were in different hospitals to the recipients. They used a portable, warm blood perfusion system to transfer the retrieved hearts. Since then, heart DCD donation programs have been introduced to the UK with great success, resulting in 17 successful heart retrievals in 2017 alone.
24.5 Successful Organ Donation Programs
There is significant variability of donation rates worldwide. Public surveys reveal that societies are supportive to organ donation. Most of the religions are also supportive although the views of different scholars may vary. Spain’s success demonstrates that continuous increase of organ donation rates is not based only on investment or even availability of intensive care beds. Spain managed to increase the donation rates despite the economic struggle that the public sector of the country faced recently. The UK and other countries have adopted the Spanish model and adapted it to their needs with positive effects on their organ donation practices.
National organizations should be formed and should be responsible for setting up practices and structures to facilitate organ donation and transplantation in a transparent and fair way. Governments should assist and resolve legal, ethical and professional issues, to ensure that all professionals are supported by clear frameworks.
The process of organ donation should be viewed as an integral part of the end of life care provided and become a normal event in hospitals. Monitoring of donation and transplantation activity should be in place in hospitals and nationally. Training of all healthcare staff involved in organ donation should be mandatory (part of the professional curriculum), and hospitals should have access to specialist-trained personnel.
The organ donation process should be seen as a continuum, and efforts to improve organ donation rates should focus on each step of the process.
Identification and Referral
The process starts from the identification of the potential donor. Nowadays, the criteria are constantly changing, and transplants centres are accepting higher risk or marginal donors. In addition, assumptions based on religious beliefs or cultural background should not be made without exploring the person’s/family’s wishes. Improvement of identification and referral rates has been observed in systems that introduced “minimal identification criteria”. A timely referral to the organ donation specialist (doctor or nurse) will ensure suitability checks and family support from trained professionals without delays.
Consent
Clinicians are faced with a grieving family. At the same time, clinicians do not have adequate training about donation. Careful planning of the conversation about donation is paramount. The best model appears to be when clinicians are supported by organ donation specialists (collaborative approach). The process of breaking bad news and breaching the subject of donation should be decoupled. Families should be allowed time to understand the course of events that led to death. Discussion about organ donation should only happen after confirmation that the family has understood and accepted the death or the reasons for WLST. If the family has not come to terms with the inevitability of their loss, organ donation should not be mentioned. The person leading the conversation must have appropriate training and be able to answer any questions the family may have. Apologetic and negative language should be avoided as organ donation is a positive act and part of the care that the dying person may wish to receive.
The concept of brain death may be confusing for grieving families as artificial means still support the body. Families should be invited to witness the clinical examination that confirms death (brainstem death testing) as this improves understanding and trust.
Organ Donor Management
Organ donor management could be challenging. Target-focused protocols help intensive care staff to maintain satisfactory organ function. Clinicians should be committed to provide the highest number of organs possible since the donor or their family have chosen organ donation as part of their end-of-life care. Failing to do so may be seen as not valuing their expressed wishes.
Potential Organ Donors in Emergency Department (ED)
Patients die in ED departments. Involving ED personnel in the organ donation process is paramount. Although ED can facilitate organ donation, it is advisable that the patient is admitted to ITU. Recent studies show that this is cost effective and also provides a better environment for the grieving family. It also protects clinicians from making incorrect early prognostication decisions.
Key Points
The ethical platform of deceased organ donation is based on the “dead donor rule”.
Deceased donation has been developed around two different programs: donation after death has been confirmed using neurological criteria (DBD) and donation after death has confirmed with circulatory criteria (DCD).
Caring for the donor: brain death is followed by a cascade of physiological changes that create very challenging physiological conditions for the physician who aims to maintain the good function of vital organs.
Standardized protocols for organ donor management have been developed worldwide with similar physiological aims.
The ischaemic injury during the dying process increases primary and delayed graft failure. There have been efforts to prevent or alter the effect of warm ischaemia to DCD organs.