Introduction

Transplantation is a life-saving and cost-effective form of treatment that enhances the quality of life for many people with end-stage chronic diseases. Transplantation surgery commenced in Australia in 1911, with a pancreas transplant in Launceston General Hospital, Tasmania. Other tissue and solid organ transplantations followed, retrieved from donors without cardiac function; the first cornea in 1941; kidney in 1956; and livers and hearts in 1968. Transplantation in New Zealand began in the 1940s with corneal grafting, and the first organ transplants were kidney and heart valve transplantation in the 1960s.¹

The first successful human-to-human transplant of any kind was a corneal transplant performed in Moravia (now the Czech Republic) in 1905.¹ In September of 1968 an ad hoc committee of Harvard Medical School produced a report on the ‘hopelessly unconscious patient.’ The committee members agreed that life support could be withdrawn from patients diagnosed with ‘irreversible coma’ or ‘brain death’ (terms they used interchangeably) and that, with appropriate consent, the organs could be removed for transplantation.¹³ The committee’s primary concern was to provide an acceptable course of action to permit withdrawal of mechanical ventilatory support for the purpose of organ donation for human transplant. In 1981, a US President’s Commission declared that individual death depended on either irreversible cessation of circulatory and respiratory functions or irreversible cessation of all functions of the entire brain. The consequent Uniform Determination of Death Act referred to ‘whole brain death’ as a requirement for the determination of brain death.¹³

Legislation that defined brain death and enabled beating-heart retrieval was enacted in New Zealand in 1964 and in Australia from 1982. This legislation heralded the establishment of formal transplant programs. In Australia, the first heart and lung program commenced in 1983, a liver transplant program in 1985, combined heart–lung transplant in 1986, combined kidney and pancreas in 1987, single lung in 1990^2,3 and small bowel in 2010. In New Zealand, bone was first transplanted in the early 1980s and the first heart transplant occurred in 1987. Skin transplantation occurred in 1991, lung transplantation in 1993, and liver and pancreas transplantation in 1998.⁴ The success of transplantation in the current era as a viable option for end-stage organ failure is primarily due to the discovery of the immunosuppression agent cyclosporin A.⁵

This chapter discusses the processes and clinical implications of cadaveric organ and tissue donation in Australia and New Zealand, within a critical care nursing context.

‘Opt-In’ System of Donation in Australia and New Zealand

There are currently two general systems of approach to seeking consent for cadaveric organ and tissue donation in operation around the world. Some countries (e.g. Spain, Singapore and Austria) have legislated an ‘opt out’, or presumed consent, system, where eligible persons are considered for organ retrieval at the time of their death if they have not previously indicated their explicit objection (see Table 27.1). In Australia, New Zealand, the US, the UK and most other common-law countries, the approach is to ‘opt in’, with specific consent required from the potential donor’s next of kin.^6,7 In some states of Australia (for example, New South Wales and south Australia) and in New Zealand people indicate consent to organ donation on their driver’s licence or the Australian Organ Donor Register.^8,9,10 In Singapore, the Human Organ Transplant Act of 1987 combines a presumed consent system with a required consent system for the Muslim population. The informed consent legislations of Japan and Korea are two of the most recent to come into force, in 1997 and 2000 respectively; before then, only living donation and donation after cardiac death were possible.^11,12

TABLE 27.1 Type of legislation by country^80–83

Note: A combined register is a register of consent and refusal.

Types of Donor and Donation

Organ and tissue donation includes retrieval of organs and tissues both after death and from a living person. Donations from a living person include regenerative tissue (blood and bone marrow) and non-regenerative tissue (cord blood, kidneys, liver (lobe/s), lungs (lobe/s), femoral heads). The implications of consent are different for each type of requested tissue. For example, the collection of bone marrow, retrieval of a kidney, the lobe of a liver or lung are invasive procedures that could potentially risk the health and wellbeing of the donor.¹⁴ In contrast, donation of a femoral head could be the end-product of a total hip replacement, where the bone is otherwise discarded. Similarly, cord blood from the umbilical cord is discarded if not retrieved immediately after birth.

After cardiac death, many people can be donors for eyes, heart valves and cardiac tissue, long bones, pelvis, tendons, ligaments and skin. On occasion, and in appropriate and controlled situations, some people could also be donors of kidneys, liver and lungs. It is after brain death that the ‘traditional’ organs of the heart, lungs, liver, kidneys, pancreas and tissues can potentially be retrieved.

Organ Donation and Transplant Networks in Australasia

The donation and transplantation process in Australia is a nationally coordinated process in the healthcare system, a unique arrangement given the disparity between state health departments and funding arrangements between federal and state health departments.

As part of the national reform package for the organ and tissue donation and transplantation sector, all state and territory health ministers agreed to the establishment of a national network of organ and tissue donation agencies, namely the Organ and Tissue Authority. This involved the employment of specialist hospital medical directors and senior nurses to manage the process of organ and tissue donation as dedicated specialist clinicians employed within the intensive care unit.¹

The responsibility for leading this group of dedicated health professionals rests with the National Medical Director who supports this team through a Community of Practice (CoP) Program. This community of health professionals, along with the staff of the Authority, are the DonateLife Network, working together to share information, build on existing knowledge, develop expertise and solve problems in a collaborative and supported manner.¹

Identification of Organ and Tissue Donors

The four main factors that directly influence the number of multi-organ donations are:

Brain Death

The incidence of brain death determines the size of the potential organ donor pool. Diagnosis of brain death is now widely accepted, and most developed countries have legislation governing the definition of death and the retrieval of organs for transplant.¹⁶ In Australia and New Zealand the most common cause of brain death has changed from traumatic head injury to cerebrovascular accident, which has implications for the organs and tissues retrieved as donors are older and often have cardiovascular and other co-morbidities.¹⁷ There is no legal requirement to confirm brain death if organs and tissues are not going to be retrieved for transplant.¹³

Two medical practitioners participate in determining brain death; in Australia one must be a designated specialist. Brain death is observed clinically only when the patient is supported with artificial ventilation, as the respiratory reflex lost due to cerebral ischaemia will result in respiratory and cardiac arrest. Artificial (mechanical) ventilation maintains oxygen supply to the natural pacemaker of the heart that functions independently of the central nervous system. Brain death results in hypotension due to loss of vasomotor control of the autonomic nervous system, loss of temperature regulation, reduction in hormone activity and loss of all cranial nerve reflexes. Table 27.2 lists the conditions commonly associated with brain death. Irrespective of the degree of external support, cardiac standstill will occur in a matter of hours to days once brain death has occurred.^13,18

TABLE 27.2 Conditions associated with brain death⁶⁵

Condition	Incidence
Hypotension	81%
Diabetes insipidus	53%
Disseminated intravascular coagulation	28%
Arrhythmias	27%
Cardiac arrest	25%
Pulmonary oedema	19%
Hypoxia	11%
Acidosis	11%

Role of Designated Specialists

According to Australian law, senior medical staff eligible to certify brain death using brain death criteria must be appointed by the governing body of their health institution, have relevant and recent experience, and not be involved with transplant recipient selection. The most common medical specialties appointed to the role are intensivists, neurologists and neurosurgeons in metropolitan centres, and general surgeons or physicians in rural settings.¹⁷

In New Zealand the role is not appointed although medical staff confirming brain death must also act independently; neither can be members of the transplant team, and both must be appropriately qualified and suitably experienced in the care of such patients.¹³ The New Zealand Code of Practice for Transplantation¹⁹ also recommends that the medical staff not be involved in treating the recipient of the organ to be removed, and one of the doctors should be a specialist in charge of the clinical care of the patient.

Testing Methods

The aim of testing for brain death is to determine irreversible cessation of brain function. Testing does not demonstrate that every brain cell has died but that a point of irreversible ischaemic damage involving cessation of the vital functions of the brainstem has been reached. There are a number of steps in the process, the first being the observation period. An observation period of at least 4 hours from onset of observed no response is recommended before the first set of testing commences, in the context of a patient being mechanically ventilated with a Glasgow Coma Scale score of three, non-reacting pupils, absent cough and gag reflexes and no spontaneous respiratory effort.¹³ The second step is to consider the preconditions (see Box 27.1). Once the observation period has passed (during which the patient receives ongoing treatment) and the preconditions have been met, formal testing can occur.

Box 27.1

Preconditions of brain death testing¹³

• Known diagnosis of injury and coma is consistent with progression to brain death.

• Exclude involvement of drugs.

• Exclude metabolic causes for coma (e.g. severe electrolyte or endocrine abnormalities).

• Exclude hypothermia (core temperature greater than 35°C).

• Systolic BP >80 mmHg.

• Confirm neuromuscular conduction.

Practice tip

When testing for corneal reflex, take care not to cause corneal abrasion, which might preclude the cornea from being transplanted if the patient is an eye donor. Invite the next of kin to observe the second set of clinical tests to assist their comprehension of brain death. Assign a support person to be with the family to assist in explaining and interpreting the testing process.⁸⁴

Formal testing for brain death is undertaken using either clinical assessment or cerebral blood flow studies.¹³ Clinical assessment of the brainstem, involving assessment of the cranial nerves and the respiratory centre (see Table 27.3) is the most common approach to testing. Brain death is confirmed if there is no reaction to stimulation of these reflexes, with the respiratory centre tested last and only if the other reflexes prove to be absent. If the patient demonstrates no response to the first set of tests, after a recommended observation period of at least 2 hours, the tests are repeated to demonstrate irreversibility.¹³

TABLE 27.3 Clinical brain death testing^13,38

If the preconditions outlined in Box 27.1 cannot be verified, brain death can be confirmed using cerebral blood flow imaging to demonstrate absent blood flow to the brain, by either contrast angiography or radionuclide scanning. Contrast angiography can be performed by direct injection of contrast into both carotid arteries and one or both of the vertebral arteries, or via the vena cava or aortic arch. Brain death is confirmed when there is no blood flow above the carotid siphon^13,20–22 (see Figure 27.1). A radionuclide scan is performed by administering a bolus of short-acting isotope intravenously or by nebuliser while imaging the head using a gamma camera for 15 minutes. No intracranial uptake of isotope confirms absent blood flow to the brain^13,20–22 (see Figure 27.2).

FIGURE 27.1 Brain death study: four-vessel cerebral angiography. Frontal cranial view of contrast flow in right internal cartoid artery (RICA). Blood flow ceases at the carotid siphon. Conclusion: if blood flow is shown to have ceased in all the vessels, there is no functioning cerebrum/cerebellum.

(Courtesy St George Hospital Radiology Department, Sydney).

FIGURE 27.2 Brain death study: cerebral perfusion HMPAO scan. Transverse, sagittal and coronal views. No uptake is seen within the cranial vault in the cerebrum or cerebellum. Blood flow is present in the sagittal and coronal views only to the carotid siphon. Conclusion: there is no functioning cerebrum/cerebellum within the cranial vault.

(Courtesy St George Hospital Nuclear Medicine Department, Sydney).

If brain death is confirmed, the time of death is recorded as the time of certification of the testing result (i.e. at the completion of the second set of clinical tests, or the documentation of the results of the cerebral blood flow scan).¹³