Apnoea testing The responsiveness of the respiratory system to hypercar- bia is the \201 nal test performed to con \201 rm brainstem death, and should not be performed if any of t he preceding tests con \201 rm the presence of brainstem function. It is recom- mended tha t end-tidal carbon dioxide (ETCO2) monitor- ing is utilized to minimize the risk of excessi ve hypercarbia and/or rapid changes in carbon dioxide tension, so limiting the risk of furt her injury to potentially recoverable brain tissue. The patient should be pre-oxygenated wi th 100% oxygen for 5min. With a SpO2 >95%, minute volume venti- lation is reduced and the E TCO2 allowed to rise slowly. Once the ETCO2 is >6.5kPa, a level high enough to exceed the n ormal threshold for stimulation of respiration, an ABG is taken to con \201 rm that the Pa CO2 is >6.5kPa. If car- diovascular stability is maintained, the patient should then be dis connected from the ventilator for 5min. Hypoxia is prevented by insuf \202 ating oxygen at 10l/min via a suction catheter placed down the ETT with continual SpO2 moni- toring. Whils t disconnected, the patient should remain apnoeic and is continually observed for any respi ratory effort (abdomen and chest exposed). If after the 5min there has been no spontaneous respiratory effort, a fur- ther con \201 rmatory ABG is taken. The ventilator should then be reconnected and the minute volume returned to the setting that allows blood gasses to re turn to the target value for the patient \200\231s further management. In patients with pre existing chronic respiratory disease who rely on a hypoxic drive to respiration, a mild b ut signi \201 cant acidosis should be achieved by allowing the PaCO2 to rise to a point wh ere the pH is <7.35. Etiology Brainstem death may follow a severe global insult such as hypoxia or a direct insu lt such as trauma or focal ischaemia resulting from vertebral/basilar artery pathology. The most common causes of brainstem death are traumatic brain injury, CVAs (including SAH), ce rebral tumors, meningitis and hypoxic brain injury. The process of con \201 rming death by neurological testing Pre-conditions Certain pre-con ditions must be met before neurological testing can be undertaken: \200 The cause of the coma must be established as an irre- versible structural cause of brain in jury. The patient must be deeply comatose, apnoeic and dependent on mechanical ventilation. The possibility of neuromuscular blockade should be excluded by means of a peripheral nerv e stimulator or the eliciting of deep tendon re \202 exes. Ventilatory depression due to d rugs or spinal cord injury must be excluded. The patient must be unresponsive with reversib le causes of brainstem depression excluded: hypothermia (<34 C), sedative drugs, alcohol, circulatory, endocrine and meta- bolic disturbances. Deviations outside normal values that are clearly a consequence of brainstem death rather than its cause do not preclude the diag nosis. Timing of testing Testing should not be considered until at least 6h after the onset of apn oeic coma or, if the cause is presumed to be hypoxic injury following cardiac arrest, many would allow a minimum of 24h after the restoration of the circulation. Establishing the irreversible loss of brainstem re \202 exes This may only take place in a setting where the above pre- conditions have been met \200 Conduct of testing Neurological testing to confirm death should be per- formed by two medic al practitioners both of whom should have held full registration with the General Medical C ouncil for at least 5yrs. One should be an ICU consultant or the consultant in charge of th e patient, and both should be competent in the procedure. Neither should have any con- nect ion to the transplant team. The doctors may perform the tests independently or together. Th ere is no statutory time interval that must pass between the two sets of tests; it is a mat ter of clinical judgment to decide when suf \201 - cient time has elapsed between tests to satisfy all those involved. Two sets are undertaken to remove the risk of observer error a nd to reassure the family. The pupils are fixed with no direct or consensual response to light. The pupils need not be dilated or equal in size and shape for the diagnosis to be con \201 rmed. The corneal re \202 ex is absent. There is no motor response within the cranial nerve dis- tribution to a painful stimulus applied centrally or periph- erally. Spinal re \202 exes may persist in brainstem dead patients. The oculovestibular (caloric) re \202 ex is absent. This is perfo rmed by injecting 50ml of ice-cold water over 1min into each external auditory meatus whils t the eyelids are \200 531 CHAPTER 32.1 Con \201 rming death using neurological criteria (brainstem death) Other considerations \200 thiopenton,e can be said to be negligible following pro- longed administration. No speci \201 c ranges can be set within which biochemical variables must fall to be considered \200\230normal \200\231 and com- patible with brainstem death testing, although recom- mend ations as such have been made by the Academy of Royal Medical Colleges. Death may be con \201 rmed after completion of the second set of tests. The time of death is then recorded as the time at which the \201 rst set of tests was completed. Documentat ion of the results should be on the appro- priate form approved by the UK Department of Hea lth. The coroner should be informed of most of these patients due to the underlying diagnos is, mechanism of injury or if organ donation is to take place. Effective communication with relatives enables under- standing of the indications for and components of brain- stem dea th testing and its implications, and may help to alleviate emotional distress. Subsequent actions After the neurological con \201 rmation of death, subsequent actions de pend on whether the patient had expressed a wish to donate their organs after death. If so, the mainte- nance of normal physiological parameters is vital to ensure optimal organ viab ility. This includes correcting the physio- logical consequences of brainstem death includi ng cardio- vascular instability (hypotension and arrhythmias), hypothermia, diabetes insipi dus, DIC, hyperglycaemia, acidosis and other metabolic and endocrine abnormalities. If dona tion is not an option, then following consultation with the relatives, withdrawal of respir atory support may take place at a time acceptable to all parties. Ancillary tests No additional tests are required in the UK to con \201 rm brainstem death, although ancillary tests such as four-ves- sel cerebral angiography, transcranial Doppler or radioiso- tope scanning may be used to establish the absence of CBF in cases of diagnost ic uncertainties. EEG or brainstem evoked potential testing are not usually helpful in esta blish- ing the diagnosis. Further reading Report of the Ad Hoc Committee of the Harvard Medical School to Examine the Definition of Brain Death. A definition of irreversible coma. JAMA 1968; 205: 337 \200\223 40. Problems \200 Depending on the underlying pathology, there may be uncertainty as to when the brain injury can be consid- ered irreversible and brainstem testing can take place. With altered pharma cokinetics in critically ill patients, uncertainty may surround the length of time that has to elapse before the effects of sedative agents, e.g. Conference of the Medical Royal Colleges and their Faculties in the United Kingdom. Diagnos is of brainstem death. BMJ 1976: 1187 \200\2238. Department of Heath and Academy of Royal Medical Colleges. A code of practice for the diagnosis of death. 2008. 532 C DANBURY Withdrawing and withholding treatment ignored, which is precisely the situation that worried Mr Burke so that he brought a case a gainst the GMC. Mr Burke requested a declaration that it would be unlawful to withdraw trea tment (in the form of arti \201 cial nutrition and hydration) against his wishes. The Cour t of Appeal ruled against him saying, \200\230Ultimately, however, a patient cannot demand that a doctor administer a treat- ment which the doctor considers is adverse to the patien t \200\231s clinical needs. \200\231 Operationalizing or cost-based futility. This de \201 nition of futility is when treatment is so unlikely to succeed that many people, both prof essional and lay persons, would consider it not worth the cost. Treatments which are now co nsidered by many as mainstream can fall into this category, such as APC. Cost is relative a nd depends on society \200\231s needs and wishes, e.g. in the aftermath of the Ladbroke Gro ve rail crash, it has been estimated that the Train Passenger Warning System installed woul d save 38 lives over 25yrs, at a cost of 15.4million per life saved. In the UK, case-law suggests that where a treatment is felt clinically appropriate, then it may not be withhel d solely on the basis of that cost. Across Europe, 13.5% of patients admitted to an ICU die. Of these patients who are going to die, 72.6% had limita- tions applied to their treatment. This equates to 10% of all ICU ad missions in this study population. Therefore, deci- sions about withdrawing and withholding treatment are occurring constantly. In the European Society of Intensive Care Medicine (ES ICM) \200\230Ethicus \200\231 paper, it was argued that there were 3 methods that could be adopted by intensiv- ists, that could lead to a patient \200\231s death: 1 Withholding tre atment was defined as a decision that was made not to start or increase a life-sustaining i ntervention. 2 Withdrawing treatment was de \201 ned as a decision that was made actively to stop a lif e-sustaining intervention presently being given. 3 Active shortening of the dying process was de \201 ned as a circumstance in which someon e performed an act with the speci \201 c intent of shortening the dying process. This is u nlawful in the UK, but not in certain jurisdictions in Europe and elsewhere in the world. C ertain authors hold that the \200\230double effect \200\231 may fall into this category. G enerally (with some exceptions, e.g. the Jewish faith), it is argued that withdrawing and w ithholding treatment are morally and ethically the same. In the USA, the President \200\231 s Commission for the Study of Ethical problems in Medicine and Biomedical Research has said , \200\230[The] healthcare professional has an obligation to allow a patient to choose fro m among the medically acceptable treatment options \200 or to reject all options. No one, however, has an obligation to provide inter- ventions that would, in his or her judgment, be counter- therapeutic. \200\231 It is establishing whether treatment options are countert herapeutic, or futile, that is dif \201 cult. Doctors rarely use the physiological de \201 nition of futility in common practice. The la tter two de \201 nitions of futility mentioned above follow utilitarian principles such as those espoused by Savulescu and Shaw and advocated by the US President \200\231s Commissio n (mentioned above), but incorpo- rate value judgements. These value judgements may be subj ect to challenge by relatives, those with power of attorney and the courts. It has been arg ued that, \200\230The prin- ciple that each individual is entitled to an equal opportu- ni ty to bene \201 t from any public health care system, and that this entitlement is proport ionate neither to the size of their chance of bene \201 ting, nor to the quality of the be ne \201 t, nor to the length of lifetime remaining in which that bene \201 t may be enjoy ed. \200\231 Futility One way of establishing whether a treatment is counter- therapeutic is by using th e concept of futility. Unfortunately, this is dif \201 cult to de \201 ne, with the court s saying, \200\230Futility is a subjective and nebulous concept which, except in the stric test physiological sense, incorporates value judge- ments. \200\231 Futility can be de \201 ned in a number of ways, includ- ing (and modifying) Ardagh \200\231s de \201 nitions \200 Best interests If futility is not as useful as it \201 rst appears, the best interests of the patient can be considered. Competent patients \200 A competent patient (see Chapter 33.1) should be involved with the decision and a discussio n should be held with the patient. As Harris has said, \200\230Each person \200\231s desir e to stay alive should be regarded as of the same importance and as deserving the same resp ect as that of anyone else, irrespective of the quality of their life or its expected durat ion. \200\231 There are some individuals who wish to die rather than continue treatment. Re cent examples in medicine include the cases of Dianne Pretty and Ms B. In justification of this wish to die, consider Kuhse \200\231s thought experiment: \200\230A truck driver and his co-driver had an accident on a lonely stretch of road. The truck caught \201 re and t he driver was trapped in the wreckage of the cabin. The co-driver struggled to free him, bu t could not do so. The driver, now burning, pleaded with his colleague \200\224an experienc ed shooter \200\224to take a ri \202 e, which was stowed in a box on the back of the truck , and shoot him. The co-driver took the ri \202 e and shot his col- league. Was what the c o-driver did morally reprehensible? Did he act wrongly? Students who are presented with Physiological futility exists when a procedure cannot bring about its physiological objecti ve. For example, it is physiologically futile if the administration of epinephrine to a hyp otensive patient fails to result in an increase in blood pressure. Bene \201 t-centered de \201 nition of futility has been de \201 ned as consisting of quantitative and qualitati ve considerations. First, the quantitative estimate of futility is one in which an interven tion is considered futile if it has failed in the last de \201 ned number of times attempt ed. For example, should a condition produce a predicted mortality of 99.9%, then 1 patient in 1000 will live if treated. It is not possible to determine which patient will survive an d which one will die in advance of treatment. In this exam- ple, treatment is futile for 99 9 patients, but not futile for one individual who could survive. The qualitative com- ponen t is defined as occurring where the patient \200\231s resulting quality of life falls well below the threshold considered minimal by general professional judgment. Note that possible considerations of the patient may be 533 CHAPTER 32.2 Withdrawing and withholding treatment The counsel of a trusted colleague is invaluable in clinical practice. It has been suggeste d that the presence of a hospital- based clinical ethics committee would help clinicians an d families in this terrible position. Such a forum would facilitate dialog between the part ies, but not provide a didactic answer. this case will generally answer both questions in the negative. The reason for their intuit ions are not hard to \201 nd. In this case, the agent was not motivated by personal gain, but by compassion. \200\231 If we accept this, then we can accept the underlying premise t hat it is sometimes in the best interests of the patient to die. Finally, there may be a way to resolve these con \202 icts through legislation. In the sta te of Texas, the Texas Advance Directives Act 1999 provides that there is a mandated period of 10 days in which care may not be withdrawn. During this time, doctors and relatives att empt to \201 nd an alternative hospital that would be prepared to continue treating the p atient. Only if no medical facility is found can there be any consideration of withdrawal o f medical care against the wishes of the family. The experience of this Act suggests that m ost disagreements between families and medical staff are resolved in the 10 day \200\230co oling off \200\231 period. Patients who lack capacity If the patient is not competent, then it is important to con- su lt widely to discover the person \200\231s past and present wishes and feelings, the belief s and values that would be likely to in \202 uence his decision, and any other factors tha t he would be likely to consider. Once this has been done, the doctor can then consider whe ther further treatment of this patient is justi \201 ed, or whether it is in the patient \200\231s best interests to cease treatment and be permitted to die. The key is to consider the individual concerned, and not merely the pathology. Process Although every case of withholding or withdrawing treat- ment is different, it is s ensible to have departmental guide- lines drawn up to guide inexperienced practitioners. Th e emphasis of care changes from one of cure to one of symptom control. It is likely that an algesics and anxiolytics are continued. It is further likely that other agents such as anti sialogogues are added. The precise treatment will vary according to the individual patient. Conclusion The pattern of death in modern society is changing from occurring at home to occ urring in hospital. The general practitioner will refer the patient to hospital when the pa tient \200\231s condition is not able to be managed in a home environment. Once in hospital , should the patient \200\231s condi- tion worsen, he or she becomes more likely to be refe rred to ICU. It is likely that more people will die on ICU as an ever-increasing number are referred. Death is traditionally perceived by the medical profession as a failure, as oppo sed to being seen as in the best interests of the patient. If death is accepted as a best i nterest, then the management of that death is paramount. Quality of death is as important a s quality of life. Intensivists have been given a new goal: to provide excellence in end-of life care. We must be ready to meet this challenge. Penalties If we get it wrong, then we risk the censure of the courts and the GMC. \200 Dr Ann David withdrew ventilatory support from a patient and administered 20mg Diazemuls. T he patient subsequently died. Consequently, on the 16th November 2005, Dr David was stuck o ff the medical register for gross professional misconduct. The Fitness to Practice Panel fo und proven that her actions were, \200\230clinically unjusti \201ed, inappropriate, prema ture and not in the patient s best interests \200\231. Dr David came to the view that furth er treatment of the patient was futile because he was not responding to her treatment and h is ventilatory requirements were increasing. Despite disagreement from the family, she with drew treatment. Dr David discussed her opinion with the patient \200\231s family, but appea rs not to have discussed the matter with her patient. Yet, he \200\230was not in imminent danger of dying and was recorded as being conscious and orientated \200\231. She knew, howe ver, that the family did not wish treatment to be withdrawn. Family \200\231s requests are not binding on clinicians because doctors have to promote their patient \200\231s best inte rests. Nevertheless, the GMC speci \201 - cally censured Dr David for her failure to treat the patient in his best interests. Further reading Ardagh M. Futility has no utility in resuscitation medicine. J Med Ethics 2000; 26: 396. Harris J. The value of life. London: Routledge, 1985. Harris J. Justice and equal opportuni ties in health care. Bioethics 1999; 13: 392 \200\223404. Kuhse H. Why killing is not always worse \200\224and sometimes better \200\224than letting die. Cambridge Q Healthcare Ethics 1998; 7: 371. Savulescu J. Consequentialism, reasons, value and justice. Bioethics 1998; 12: 212. Shaw AB. In defense of ageism. J Med Ethics 1994; 20: 188. Sprung CL, Cohen SL, Sjokvist P, et al. End-of-life practices in European intensive care units: the Ethicus study. JAMA 200 3; 290: 790. R (on the application of Burke) v General Medical Council [2004] All ER (D) 588 (Jul) and [2005] EWCA 1003. R v North Derbyshire HA, ex parte Fisher [1997] 8 Med LR 327 North West Lancashire HA v A,D and G [1999] Lloyd \200\231s Rep Med 399 Consider the busy hospital, with high pressure on beds; the consultant, unable to take time to establish a rapport with the family; working with limited access to an appropriate peer group. There are a number of factors that could help minimize the occurrence of unfortunat e episodes. \200 Ms B v An NHS Hospital Trust. [2002] WL 347038 Case of Pretty v United Kingdom. (2002) 35 E .H.R.R. 1 Doctors should establish local, regional and national networks of support to which to turn for advice. 534 I THOMAS & AR MANARA The potential heart-beating organ donor Organ transplantation is one of the most significant medical advances of recent times, with >90% of recipients surviving 1yr. This success has led to a situation worldwide whereby de mand for organs outstrips supply. The trans- plantation of organs in suboptimal conditions is a sig ni \201 cant cause of graft failure. It is therefore vital that comprehen- sive p hysiological support is given to a potential organ donor to ensure that donated organs reac h the recipients in optimal condition. Clinicians caring for an organ donor have a duty of care and obligation to both the donor and the recipient to ensure that this is the case. fiscal, depending on the circumstances of the death, and should be sought prior to approach ing the donor \200\231s relatives. Pathophysiological changes after death according to neurological criteria Pathophysiologica l changes occur in all major organ sys- tems after the irreversible loss of brainstem re \202 exes, all of which may jeopardize function in potentially transplantable organs (Table 32.3.1). Table 32.3.1 Incidence of pathophysiological changes after death according to neurological criteria Identi \201 cation of the potential organ donor Organ donation is widely supported, with > 14 million (23%) of the UK \200\231s population actively expressing a wish to donate their organs after death by registering on the UK Transplant \200\231s Organ Donor Register. Few of these people will die in an ICU and, of those who do, only 6% will have death con \201 rmed using neurological criteria. To ensure that the wishes of dying patients are met, any patient under the age of 75 years who has been con \201 rmed dead using neuro- logical cri teria should be considered as a potential heart- beating organ donor, and their relatives s hould be offered the option. There are very few absolute contraindications to organ donatio n: \200 Hypotension Diabetes insipidus Disseminated intravascular coagulation Cardiac arrhythmias P ulmonary oedema Metabolic acidosis 80% 65% 30% 30% 20% 10% Cardiovascular changes Irreversible loss of brainstem re \202 exes is associated with inte nse autonomic activity and massive catecholamine release. The resulting increases in heart rate, blood pres- sure, cardiac output and PVR lead to widespread myocar- dial ischaemic da mage. Impaired ATP production, increased free radical production and defective oxidative me tabolism exacerbate the cellular damage and worsen myocardial function. ST segment and T wa ve changes are common, along with atrial or ventricular arrhythmias and conduction abnormal ities. Multi-factorial in origin, these changes re \202 ect loss of vagal tone, sympatheti c overactivity, myocar- dial ischaemia, electrolyte abnormalities and/or the admin- istrati on of exogenous catecholamines. As vasomotor control by the brainstem is lost, all sympathe tic activity is lost, resulting in profound vasodilatation and myocardial depression with c onsequent hypotension. This hypoten- sion may be potentiated by other factors (Table 32.3.2 ). Asystolic cardiac arrest is likely to occur within days if no other organ support except mechanical ventilation is provided. Presence of malignancy (except certain primary tumors of the CNS) Systemic sepsis Con \201 rmed diagnosis of HIV Known or suspected classical or variant CJD \200 \200 In order to avoid missing potential organ donors, all such patients should be discussed wit h the donor transplant coordinator regarding suitability, as \200\230marginal \200\231 org ans may still be transplanted if the clinical situation of the recipient demands it. Until recently hepatitis B- or C-positive donors were not considered suitable for donation, but o rgans from these patients are now transplanted into hepatitis B- or C-positive recipients Approaching a potential donor \200\231s family Once a potential donor has been discussed wi th the donor transplant coordinator, the suitability of the patient can be determined, avoi ding the situation whereby a patient \200\231s rel- atives are approached with a request fo r organ donation only to \201 nd subsequently that they are not suitable. They are also a ble to check with the organ donor register to see if the patient had registered their wish to donate their organs after death. An approach to the relatives requesting organ donation should be made by an experienced mem- ber of the ICU team with or without the transplant co or- dinator present. No member of the transplant team should be involved with the request f or organ donation. There is some evidence to suggest that a collaborative approach to the f amily by the patient \200\231s clinician and the transplant coor- dinator achieves higher c onsent rates, although these \201 nd- ings need to be confirmed. Relatives should be full y informed of progress at every stage, and time taken to explain the need for ongoing thera peutic interventions aimed at optimizing the function of potentially transplant- able organ s after con \201 rming death. Permission for dona- tion may be required from the coroner o r procurator s Table 32.3.2 Causes of hypotension after death according to neurological criteria Peripheral vasodilatation Hypovolaemia Diabetes insipidus Osmotic diuresis (mannitol) Hyper glycaemia Therapeutic \202 uid restriction Myocardial depression Depletion of high energy phosphate Mitochondrial inhibition Possible reduction in T3 production Electrolyte disturb ance 535 CHAPTER 32.3 The potential heart-beating organ donor Cardiovascular support Early donor optimization increases the rate of successful organ retr ieval. Suggested haemodynamic targets are: \200 \200 \200 \200 Pulmonary changes Neurogenic pulmonary oedema resulting initially from elevated pulmonary c apillary hydrostatic pressure caused by acute LV dysfunction followed by increased capillar y permeability is common after a severe intracranial injury. Pulmonary dysfunction may also occur as a result of pneu- monia, contusions, aspiration, atelectasis, \202 uid overload or as part of any other coincidental disease process. CVP 4 \200\22310mm Hg Cardiac index 2.2 \200\2232.5l/min/m-2 MAP 60 \200\22380mm Hg Pulse r ate 60 \200\223100/m ideally sinus rhythm Hypotension should initially be treated with \202 uids guided by CVP and/or cardiac outpu t monitoring. Excessive \202 uid administration should, however, be avoided, particularly if the lungs are being considered for transplantation since they may have been damaged dur ing the period of sympa- thetic hyperactivity and are susceptible to volume over- load and capillary leakage. Measuring EVLW and maintaining it in the normal range may increase the r ate of successful retrieval of the lungs for transplantation. If hypotension persists despi te adequate \202 uid resuscitation, then vasopressin is increasingly considered to be the vaso- constrictor of choice since, unlike other inotropes and vasoconstrictors, it does no t deplete myocardial ATP levels whilst increasing blood pressure, maintaining cardiac out- put and reducing plasma hyperosmolality. Once a patient is considered suitable for organ do nation, vasoconstrictors such as norepinephrine that had been used to maintain CPP should b e stopped and vasopressin used instead. Dopamine or norepinephrine should be used when \202 uids and vasopressin fail to achieve the optimization targets. Prolonged administratio n of exogenous catecholamines should be avoided as rapid depletion of myocardial ATP stores and detrimental vasoconstriction in donor organs may result. If high doses of vasoactive d rugs are required, \200\230hormone replacement \200\231 (see below) may be considered. Arr hythmias are common and should be aggressively treated along with any associated hypokalaem ia or hypomagnesaemia. Endocrine changes Failure of the anterior and posterior pituitary leads to reduced circulat ing levels of ADH, cortisol, T3 and T4. Diabetes insipidus occurs in up to 65% of potential organ donors, and is characterized by diuresis, hypovolaemia and metabolic derangement (pl asma hyperosmolality, hypernatraemia, hypomagnesaemia and hypocalcaemia). Lack of T3 may co mpound cardiovascular collapse through depletion of high energy phosphates, whilst a reduce d blood cortisol level impairs the donor stress response. Insulin secretion is reduced and contributes to the devel- opment of hyperglycaemia. This may be aggravated by the administr ation of glucose-containing fluids to manage hypernatraemia and of exogenous catecholamines to treat hypotension. Left untreated, hyperglycaemia leads to increased plasma osmolality, metabolic acidosis, osmotic diuresis and cardiovascular instability. Temperature regulation Hypothermia is a common feature and results from loss of hypothalami c temperature-regulating mechanisms, a reduction in heat production due to a decreased meta - bolic rate, and increased heat loss due to peripheral vasodilatation Hematological changes The release of tissue thromboplastin and other mediators from severel y damaged brain tissue may cause a coagulop- athy, DIC being present in 30% of organ donors . Respiratory support If the lungs are being considered for transplantation then, to minimize the risk of oxygen toxicity, the FiO2 should be kept as low as possible to achieve a PaO2 >10kPa. A ventila- tory strategy aimed at protecting the lungs should be employed, with tid al volumes limited to 6 \200\2238ml/kg. A PEEP of 5 \200\22310cm H2O will prevent alveolar collapse, whilst higher levels may induce hypotension in an inadequately \202 uid- resusc itated patient. Donor lungs are vulnerable to pulmo- nary oedema. and \202 uid loading to a CVP >6mm Hg (in the absence of PEEP) may worsen the arterial alveolar oxygen gradient. Immunological changes The process of brainstem death alters the immunogenecity of organs by a variety of poorly understood mechanisms. This may explain why acute rejection episodes a re more frequent and more severe in recipients of organs from heart-beating donors compared with those receiving organs from living donors. Clinical management of the potential heart-beating organ donor Once death has been con \201 rmed using neurological criteria, there is an alteration in the emphasis of patient ca re. Whereas therapies have previously been aimed at preserv- ing brain function, they are n ow directed to optimize the function of transplantable organs. High quality routine general intensive care measures should continue, including strict asepsis, nutrition, regular trac heal suctioning, physio- therapy, turning and the active treatment of infection or arrhythm ias. Additionally, speci \201 c therapies to control or reverse the pathophysiological abn ormalities that may damage or impair the function of transplantable organs should be instig ated. Invasive monitoring should be contin- ued or commenced. If new lines are inserted, th e arterial cannula should ideally be sited in the left radial or brachial artery and centra l venous or pulmonary arterial catheter in the right internal jugular vein as a result of t he order in which the great vessels are ligated during organ retrieval. Endocrine support Diabetes insipidus: hypovolaemia and hypernatraemia should be corrected w ith appropriate IV \202 uid administra- tion. Excessive polyuria should be managed with D DAVP which can be administered either as intermittent boluses or as an infusion. DDAVP is a ssociated with a lower inci- dence of acute tubular necrosis and graft failure than vaso- p ressin. Hyperglycaemia should be treated with an insulin infusion according to usual intens ive care protocols. 536 I THOMAS & AR MANARA Other hormone replacement should be considered in organ donors with cardiovascular instabil ity, escalating vasoactive drug requirements and a worsening acidosis. \200 performed, local policy may dictate that intravascular can- nulae, the ETT and urethral cat heter are left in place, oth- erwise they may be removed. Last of \201 ces are performed b y the nursing staff with help from the transplant coordina- tor, and the relatives should b e given the opportunity to view the body after surgery if they wish to do so. Meeting the w ishes of individuals and their relatives to donate organs after death is an important aspec t in bereavement care. The attitudes of medical staff in explain- ing the need for ongoing therapies despite the donor being declared dead will lead to greater understanding on the p art of the relatives, many of whom gain comfort from following their relative \200\231s wis hes after death and consola- tion in knowing that some good has come from their trag- edy. Psychological and pastoral support offered to relatives by the ICU team and the transplant coordinator may help alleviate feelings of guilt, anger or remorse. They should be invited to return and discuss any issues with ICU staff or the coordinator in the future. It is com mon practic for relatives to be informed of the patients that bene \201 ted from the donat ion of their loved one \200\231s organs. Some cardiothoracic transplant centers recommend using T3 to reduce inotrope requirements a nd help restore cardiovascular stability, hoping that this will improving the function of t he transplanted heart The administration of high dose methylprednisolone has been advocated to reduce vasoactive drug requirements, to attenuate the effects of proin \202 ammatory c ytokines, and to reduce the accumulation of lung water. It improves oxygenation in the dono r and is associated with increas- ing likehood of successful retrieval and transplantation of the lungs. On the basis of the failure of the hypothalamo-pituitary axis, others have suggested that \200\230hormonal resuscitation \200\231 with vasopressin, methylprednisolone and T3 should be more routine since its administration has been associated with an increase in the possib ility of the kidney, heart, liver, lung and pancreas being transplanted, along with an impr ovement in the short-term function of the donor heart. In practice whether it is used or no t is determined by the preferences of the Transplant Center involved. Further reading Barber K, Falvey S, Hamilton C, et al. Potential for organ donation in the United Kingdom: audit of intensive care records. BMJ 2006; 352: 1124 \200\2236. Renal support Renal perfusion pressure should be optimized by maintain- ing an adequate MAP with \202 uid resuscitation or vasoactive drugs as appropriate. Episodes of hypotension should be treated aggressively as they are associated with acute tubular necrosis and failu re of the transplanted kidneys. Pennefather SH, Bullock RE, Dark JH. Use of low dose arginine vasopressin to support brain dead organ donors. Transplantation 1995; 59: 58 \200\22362. Pennefather SH, Bullock RE, Dark JH. The effect of \202 uid therapy on alveolar arterial oxygen gradient in brain dead organ donors. Transplantation 1993; 56: 1418 \200\22322. Hematological support Any coagulopathy should be corrected with the adminis- tration of FFP and platelets. Four units of blood should be available prior to multi-organ procurement si nce the surgery may involve signi \201 cant blood loss. Rosendale JD, Kauffman MH, McBride MA, et al. Aggressive pharmacologic donor management res ults in more transplanted organs. Transplantation 2003; 75: 482 \200\2237. Shafer TJ, Ehrle RN, Davis KD, et al. Increasing organ recovery form level 1 trauma centers : the in-house coordinator intervention. Prog Transplant 2004; 14: 250 \200\22363. Temperature support Normothermia should be restored and maintained using forced air warming blankets, IV \202 uid warmers, heated and humidi \201 ed inspired gasses and, if necess ary, by increasing the ambient temperature Sque, M, Long, T. and Payne, S. Organ and tissue donation: exploring the needs of families. Final report of a three-year study commis- sioned by the British Organ Donor Society, fund ed by the National Lottery Community Fund. University of Southampton, 2003. http://eprints. soton.ac.uk/11140/ Other considerations Documentation should be continued as for any critically ill patient. T he time of death is recorded as the time that the \201 rst set of tests con \201 rming d eath according to neuro- logical criteria is completed. If a post-mortem is to be The Intensive Care Society \200\231s Working Group on Organ and Tissue Donation. Guidelines for adult organ and tissue donation, 2004. http://www.ics.ac.uk/icmprof/downloads/Organ% 2 0&%20Tissue%20Donation.pdf This page intentionally left blank 538 I THOMAS & AR MANARA Non-heart-beating organ donation Background Organ transplantation offers patients with end-stage organ failure an improved q uality of life and increased life expect- ancy. In non-heart-beating organ donation (NHBD), organs are retrieved form a donor following cardiorespiratory arrest rather than after the con \201 rmation of death using neurological criteria. This is not a new concept. Prior t o recognition in 1968 by the Harvard Medical Committee that death resulted from irreversibl e damage to the brain- stem and the introduction in 1976 of clinical tests to con- firm dea ths using neurological criteria, organs for transplantation were routinely retrieved from N HBDs. After this declaration, transplant centers rapidly switched to transplanting organs f rom patients declared dead using neurological criteria, i.e. heart-beating donors, and the practice of NHBD declined rapidly. However, with the gap between organ supply and demand wi dening and the demonstration that kidneys retrieved from NHBDs have the same long-term outc ome as those from brainstem dead donors, transplant centers are re-introducing NHBD schemes . Table 32.4.1 The modi \201 ed Maastricht classi \201 cation of NHBDs Category I Category II Category III Category IV Category V Dead on arrival Unsuccessful resuscitation Anticipated cardiac arrest Cardiac arrest in a b rainstem dead donor Unexpected cardiac arrest in an ICU patient Potential NHBD Patients suitable for NHBD are typically, but not exclusively, those who hav e experienced a catastrophic brain injury but who do not ful \201 l the neurological crite ria for death. They are dependent on life-sustaining support, yet contin- ued medical inter vention is not considered to be in the patient \200\231s best interests. As a result, withd rawal of active treatment has been planned and it is anticipated that cardi- orespiratory a rrest will follow quickly and predictably. Patients with other diagnoses in whom treatment with- drawal is planned may also be suitable and should be dis- cussed with the donor trans plant coordinator to assess suitability. Absolute contraindications to NHBD are the same as those described for brainstem dead heart-beating donors.