Organ Donation
Dr James F PeerlessMay 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 2011/12
• 1 088 deceased donors– 436 DCD donors– 652 DBD donors
• On 31 March 2012, there were 7 636 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
Source: Transplant activity in the UK, 2011-2012, NHS Blood and Transplant
777 770 751 764 793 809 899 959 1010 1088
2388 23962241 2196
2385 23812552 2644 2695
2905
780079977877
6698
6142
56735654
7219
7655 7636
0
1000
2000
3000
4000
5000
6000
7000
8000
2002-2003 2003-2004 2004-2005 2005-2006 2006-2007 2007-2008 2008-2009 2009-2010 2010-2011 2011-2012
Year
Nu
mb
er
Donors
Transplants
Transplant list
Number of deceased donors and transplants in the UK, 1 April 2002 - 31 March 2012,and patients on the active transplant lists at 31 March
Source: Transplant activity in the UK, 2011-2012, NHS Blood and Transplant
1 Hearts – in addition to age criteria, donors who died due to myocardial infarction are excluded
0
10
20
30
40
50
60
70
80
90
100
Organs fromactual DBD
donors
Donor agecriteria met
Consent fororgan donation
Organs offeredfor donation
Organs retrievedfor transplant
Organstransplanted
Pe
rce
nta
ge
Kidney Liver Pancreas Heart Lungs
Donation and transplantation rates of organs from DBD organ donors in the UK, 1 April 2011 – 31 March 2012
% of all organs
% of all organsmeeting age
criteria1
86%85%
30%
24%21%
86%85%
41%
25%28%
1
Transplanted:
Source: Transplant activity in the UK, 2011-2012, NHS Blood and Transplant
Donation and transplantation rates of organs from DCD organ donors in the UK, 1 April 2011 – 31 March 2012
0
10
20
30
40
50
60
70
80
90
100
Organs fromactual DCD
donors
Donor agecriteria met
Consent fororgan donation
Organs offeredfor donation
Organs retrievedfor transplant
Organstransplanted
Pe
rce
nta
ge
Kidney Liver Pancreas Lungs
% of all organs
% of all organsmeeting age
criteria
82%
30%
12%
4%
82%
30%
20%
6%
Transplanted:
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 excluded3. 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 (FiO2 1.0) for 10 minutes– Allow PaCO2 to rise to 5.0kPa.
• Patient is disconnected from ventilator– O2 passed down ETT via suction catheter at 6 Lmin-1 to maintain
oxygenation
• Direct clinical observation to confirm apnoea over 10 minute period– PaCO2 is allowed to rise to >6.65kPa.
• If respiratory threshold of 6.65 kPa not exceeded after 10 minutes:– Apnoea continued and PaCO2 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 arrivalII. Unsuccessful resuscitationIII. Awaiting cardiac arrestIV. Cardiac arrest in DBDV. 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, 2005.• 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): 225-9
• Statistics and Clinical Audit, NHS Blood and Transplant. Overview of Organ Donation and Transplantation. NHS Blood and Transplant, 2012. http://organdonation.nhs.uk/statistics/transplant_activity_report/current_activity_reports/ukt/activity_report_2011_12.pdf