Organ Donation Dr James F Peerless May 2013

Objectives Background Brain-stem death Donation after brain death Donation after circulatory death Ethical issues

Syllabus Annex C – Anaesthesia for neurosurgery, neuroradiology and neuro critical care NA_IK_23 Explains the issues related to the management of organ donation in neuro-critical care – General, urological and gynaecological surgery GU_IK_04 Recalls/ describes the ethical considerations of cadaveric and live-related organ donation for the donor [and relatives], recipient and society as a whole – Trauma and stabilisation MT_IK_09 Describes the specific ethical and ethnic issues associated with managing the multiply injured patient, including issues that relate to brain stem death and organ donation Annex F – Domain 8: End of life care 8.1 Manages the process of withholding or withdrawing treatment with the multi-disciplinary team 8.2 Discusses end of life care with patients and their families/surrogates 8.3 Manages palliative care of the critically ill patient 8.4 Performs brain-stem death testing 8.5 Manages the physiological support of the organ donor 8.6 Manages donation following cardiac death

History Organ transplantation is the removal of an organ and placement in another site – Either allograft or autograft Numerous accounts throughout history – Issues mainly limited by degradation of organs and host rejection – 1905: first corneal transplant – 1950: first successful kidney transplant Holy grail is the generation of organs from patients’ stem cells

Types of Donor DBD/HBD – Donation after brain death – Heart beating donor DCD/NHBD – Donation after cardiac death – Non-heart beating donor Living donors

Introduction Organ transplantation offers hope to patients with end-stage organ failure. Can help bereaved families find solace Advances in medicine and an ageing population have brought about a demand which far outstrips organ availability UK has a low donor rate compared with many European countries – Spain 34 pmp – UK 16 pmp

Introduction Number of DBD patients is decreasing due to: – Fewer young people dying of catastrophic cerebrovascular events – Advances in treatment of traumatic brain injury and intracranial haemorrhage

Statistics for 2011/ deceased donors – 436 DCD donors – 652 DBD donors On 31 March 2012, there were patients on the transplant list During 2011/12: – 508 patients died whilst on the list – 819 patients were removed from the list Ill-health Ineligible

Approaching the Family Doctors’ task is to identify suitable donors SN-ODs are specially trained to discuss organ donation with relatives, and have a higher consent success rate. Essential that requests are made with sensitivity and compassion

Brain stem death

Brain stem Death A state of irreversible loss of consciousness associated with the loss of central respiratory drive Accepted as equivalent to somatic/cardiorespiratory death as it represented a state when “the body as an integrated whole has ceased to function”. World Medical Association, 1968

Diagnosis of brain stem death Brain stem death is diagnosed in three stages: 1.It must be established that the patient has suffered an event of known aetiology resulting in irreversible brain damage with apnoeic coma 2.Reversible causes of coma must be excluded 3.A set of bedside clinical tests of brain stem function are undertaken to confirm the diagnosis of brain stem death

Reversible Causes of Coma Sedative drugs – Beware prolonged action, especially in presence of hypothermia, renal failure and hepatic failure Neuromuscular blocking agents Hypothermia – Core temperature must be >34°C Circulatory, metabolic or endocrine disturbances – Pathophysiological changes commonly occur following brain stem compression and death.

The Test Absent pupillary light reflex Absent corneal reflex Absent vestibulo-ocular reflex No motor response to central stimulation Absent gag reflex Absent cough reflex Absence of respiratory movements during apnoea test

Apnoea Test Patient pre-oxygenated (F i O 2 1.0) for 10 minutes – Allow P a CO 2 to rise to 5.0kPa. Patient is disconnected from ventilator – O 2 passed down ETT via suction catheter at 6 Lmin -1 to maintain oxygenation Direct clinical observation to confirm apnoea over 10 minute period – P a CO 2 is allowed to rise to >6.65kPa. If respiratory threshold of 6.65 kPa not exceeded after 10 minutes: – Apnoea continued and P a CO 2 rechecked until threshold exceeded.

Notes on brain stem testing Brain stem testing must be performed by at least two medical practitioners: registered with the GMC for more than five years at least one should be a consultant, and competent in testing not members of the transplant team Two sets of tests are performed: to remove the risk of observer error to re-assure the family no strict time interval between tests (clinical judgment)

Notes on brain stem testing Time of death: legal time of death is when the first set of tests indicates brain stem death Spinal reflexes: Peripheral muscle movements in response to peripheral stimulation – neural pathways in the spinal cord with no higher neural input. May occur following peripheral stimulation both during testing and at other times – should be explained to relatives

Donation after Brain Death

DBD Donation from heartbeating donors offers advantages due to the minimal time between loss of circulation and cold perfusion Important to recognise the changes that occur in a DBD and actively manage these – Suboptimal management reduces quality and quantity of number of organs for transplantation

DBD Brain stem death causes widespread physiological changes – Cardiovascular – Respiratory – Endocrine – Metabolic – Haematological

Pathophysiology Coning – Increased ICP  HTN to maintain CPP – High ICP  brain herniation, pontine ischaemia and a hyperadrenergic state – Pulmonary hypertension occurs – Increased afterload (both sides)  myocardial ischaemia and NPO – Cushing’s Reflex – occurs in 1/3 patients secondary to baroreceptor activity and midbrain activation of the PNS.

Cardiovascular Collapse Phase Following herniation – Loss of sympathetic activity  reduction in vascular tone Vasodilatation and hypotension Reduced cardiac output Reduced preload and afterload  reduced aortic diastolic pressure  reduced myocardial perfusion

Endocrine Diabetes insipidus – Pituitary ischaemia  reduced ADH secretion High fluid losses Electrolyte disturbances Metabolic rate – Reduced movement, reduced activity – Reduced circulating [T3] Hypothermia – Hypothalamic dysfunction

Pulmonary Dysfunction common Worsening existing condition – Pneumonia – Aspiration Related to TBI – Neurogenic pulmonary oedema

Haematological Tissue thromboplastin – Released by ischaemic brain tissue – Leads to a number of coagulopathic disorders, including DIC Need to cross-match 4 units for organ harvesting

DBD All systems need to be preserved and optimized as best as possible to enhance chance of successful organ transplantation Retrieval teams will request blood sampling – Pre-transplantation renal function – Coagulation Maintain cardiovascular stability Monitor fluid balance

Donation after Circulatory Death

DCD The retrieval of organs for transplantation following death confirmed by circulatory criteria Has been reintroduced to help contribute to donor numbers DCD should be considered in all patients where continued treatment is futile, but do not meet brain death criteria

When & where Modified Maasticht Classification of DCDs I.Dead on arrival II.Unsuccessful resuscitation III.Awaiting cardiac arrest IV.Cardiac arrest in DBD V.Unexpected cardiac arrest in critically ill patient

Organ retrieval quality Warm ischaemia time limits the type of organs that can be successfully retrieved Causes irreversible damage due to accumulation of ischaemic metabolites Warm ischaemia – Commences when SAP < 50 mmHg, SaO2 <70 %, until cold perfusion initiated Cold ischaemia – From cold perfusion to warm circulation following transplantation

DCD - Organs Kidney (2 hours) Liver (30 minutes) Pancreas (3o minutes) Lung (1 hour) Tissue – Cornea – Bone – Skin – Heart valves

DCD - Contraindications No age limit HIV vCJD Haematological malignancy Active invasive Ca within last three years

DCD - The process Decision to withdraw made Transplant coordinator involvement Discussion with family [coroner referral] Continue current levels of treatment – Controversies regarding escalation Retrieval team prepraed in theatre Withdrawal of treatment occurs

DCD - Ethical Issues Potential for conflict of interest with DCD patients regarding withdrawal of treatment, end of life care, and suitability for organ donation Concerns about adjusting end of life care to facilitate donation Uncertainty regarding how soon organ retrieval can begin following circulatory death

Summary Recognition and treatment of physiological changes during DBD increase chance of successful organ donation DCDs make a modest but increasing contribution to the donor pool Decisions regarding organ donation should be routinely incorporated into end-of-life care

References ICS Working Group on Organ & Tissue Donation. Guidelines for Adult Organ and Tissue Donation. UK Intensive Care Society, Dunne K, Doherty P. Donation after circulatory death. Continuing Education in Anaesthesia, Critical Care & Pain, 2011; 11(3): 83-6 Manara A, Murphy P, O’Callaghan G. Donation after circulatory death. British Journal of Anaesthesia, 2012; 108 (supplement 1): i108-i121 Gordon J, McKinlay J. Physiological Changes after Brain Stem Death and Management of the Heart-beating Donor. Continuing Education in Anaesthesia, Critical Care & Pain, 2012; 12(5): Statistics and Clinical Audit, NHS Blood and Transplant. Overview of Organ Donation and Transplantation. NHS Blood and Transplant, urrent_activity_reports/ukt/activity_report_2011_12.pdf