Skip to content

title: Death and the Brainstem Dead Patient author: "Callum Taylor" output: html_document: css: styles.css tags: notebook: 🌑-FFICM

Flashcard type:basic
What code of practice do we (clinicians) use when diagnosing death? Academy of Medical Royal Colleges (2008)
What do the courts in England use when determining death? 1976 Royal Colleges "Brain Death Criteria"
How long does the Academy of Medical Royal Colleges code of practice on death recommend that you wait to check for presence of heart sounds/pulse/resp effort? 5 minutes
Is HIV infection a relative or absolute contraindication to organ donation? Absolute
Is cancer a relative or absolute contraindication to organ donation? Absolute
Are there age limits for organ donations? No
How many people die a day waiting for an organ transplant in the UK? 3

Anki Cloze:

Flashcard type:cloze
The {{c1::2008 Academy of Medical Royal Colleges::year and name}} definition of death requires both: the {{c2::irreversible loss of the capacity for consciousness::criterion}} and the {{c3::irreversible loss of the capacity to breathe::criterion}}
The two forms of death that the 2008 Academy of Medical Royal Colleges code of practice recognise are: {{c1::irreversible cessation of brain-stem function::form}} and {{c2::cessation of cardiorespiratory function}}

Diagnosis of Death

There was a code of practice issued by Academy of Medical Royal Colleges in 2008, updating the 1998 guidance. 1

There is no statutory defn of death in the UK. The courts in England and Northern Ireland have used the 1976 Royal Colleges "Brain Death Criteria". The 2004 Human Tissue Act uses a definition of death for the purposes of the act onlty. 1

Defn

Death entails the irreversible loss of those essential characteristics which are necessary to the existence of a living human person and, thus, the definition of death should be regarded as the irreversible loss of the capacity for consciousness, combined with irreversible loss of the capacity to breathe. 1

This can be:

  • Death following the irreversible cessation of brain-stem function
  • Death following cessation of cardiorespiratory function 1

They note the irreversible loss of capacity for consciousness is not enough to mean death, you need to also be unable to breath unaided without resp support. 1

They note that also you don't need cessation of all neuro activity in brain. That you can still have some residual reflex movement of limbs after a diagnosis. 1

Diagnosis of cardirespiratory death can be diagnosed with medical practitioner confiming irreversible cessation of neuro (through pupillary), cardiac, and resp activity. 1

There were no standardised criteria for confirmation of death following irreversible cessation of cardiorespiratory function.1

The royal colleges recommended criteria for cardiorespiratory arrest death confirmation being:

  • "The simultaneous and irreversible onset of apnoea and unconsciousness in the absence of the circulation"
  • "Full and extensive attempts at reversal of any contributing cause to the cardiorespiratory arrest have been made."
  • "One of the following is fulfilled:
    • the individual meets the criteria for not attempting cardiopulmonary resuscitation
    • attempts at cardiopulmonary resuscitation have failed
    • treatment aimed at sustaining life has been withdrawn because it has been decided to be of no further benefit to the patient and not in his/her best interest to continue and/or is in respect of the patient’s wishes via an advance decision to refuse treatment"
  • "The individual should be observed by the person responsible for confirming death for a minimum of five minutes to establish that irreversible cardiorespiratory arrest has occurred."
    • "absence of a central pulse on palpation"
    • "absence of heart sounds on auscultation"
    • "However, their use can be supplemented in the hospital setting by one or more of the following"
      • asystole on a continuous ECG display
      • absence of pulsatile flow using direct intra-arterial pressure monitoring
      • absence of contractile activity using echocardiography
  • "Any spontaneous return of cardiac or respiratory activity during this period of observation should prompt a further five minutes observation from the next point of cardiorespiratory arrest"
  • "After five minutes of continued cardiorespiratory arrest the absence of the pupillary responses to light, of the corneal reflexes, and of any motor response to supra-orbital pressure should be confirmed"
  • "The time of death is recorded as the time at which these criteria are fulfilled." 1

Conditions for Irreversible Cessation of Brain Stem Function

Aetiology

Needs to be known aetiology. 1

If there are significant diagnostic uncertainties then brain stem testing cannot be undertaken. 1

But if cause cannot be fully established despite investigation then brain stem testing can be performed if there is "no possibility of a reversible or treatable underlying cause being present" 1

You need to exclude any reversible causes and no evidence of depressant drugs causing state, and reversal agents should be used if needed. You can't be too cold, you need to be > 34, you need to exclue circulatory, metabolic, and endocrine causes. 1

Conditions

  • MAP > 60
  • Normocarbia
  • No hypoxia
  • No Acidaemia/Alkalaemia (pH 7.35 to 7.45)
  • Sodium should be more than 115 and less than 160 but this is guidance
  • K needs to be > 2 to avoid confusion from loss of reflexes
  • Similarly phosphate (<3) and magnesium (>0.5) need to be normal enough
  • Use a peripheral nerve stimulator to double check
  • Sugars need to be > 3 and should be checked immediately before 1

Criteria

  • Fixed Pupils, No Response to Sharp Changes in Intensity of Light
  • No corneal reflex
  • Oculo-Vestibular reflexes are absent
    • No eye movements following slow injection of 50mls of icecold water over one minute, into each ear in turn. You should check the tympanic membrane first, and head should be turned 30 deg to horizontal
  • No motor responses in cranial nerve or somatic distribution in response to supraorbital pressure
  • No cough reflex from bronchial stimulation by suction catheter
  • Lastly test for hypercarbia (apnoea test) 1
    • Increase FiO2 to 1
    • Check ABG to ensure that PaCO2 and SaO2 correlate with monitored values
    • When O2 greater than 95%, reduce minute volume ventilation by lowering resp rate to allow slow rise in EtCO2
    • When ETCO2 greater than 6 check ABGs to confirm PaCO2 is at least 6 and pH is less than 7.4 (If patient has chronic CO2 retention then targets are greater than 6.5 and less than 7.4)
    • Keep BP stable, and if so, move onto next stage
    • Disconnect from ventilator and attach to O2 flow of 5L/min through endotracheal catheter for 5 minutes
    • If desaturates than CPAP can be used
    • If no spont resp effort after 5 minutes then no resp centre activity can be documented, and double check that PaCO2 has increased by more than 0.5KPa
    • Now you can reconnect ventilator 1

In paeds when over age of two months you can use same criteria as adults. Before this age you can rarely use these criteria. 1

You should do this testing twice. It needs to be two medical practitioners registerd for more than five years and who are competent. At least one are a consultant. Neither doctor should be a member of the transplant team. 1

You don't need a long delay between first test and second test. 1

You don't confirm death until second test, but legally time of death is first death test. 1

Other potentially useful tests when you can't use brainstem reflexes:

  • 4 Vessel Angio
  • Transcranial Doppler
  • MR Angio
  • Spiral CT Angio
  • HMPAO Spect
  • Xenon CT
  • PET
  • EEG
  • Evoked Potentials 1

Management of Heart-Beating Donor

Pathophysiology of Brain Stem Death

Increased ICP causes arterial pressure to rise to maintain cerebral perfusion pressure. But if ICP gets too high then brain will herniate. Pontine ischaemia will occur, as will hyper adrenergic and pulmonary hypertension. This will increas afterload to heart causing myocardial ischaemia. Cushings reflex (high BP with bradycardia) only happens in about 1/3 of patients. Then after foramen magnum herniation, spinal cord sympathetic activity will be lost and loss of vasomotor tone. So you then get vasodilatation and impaired cardiac output. Preload and afterload both fall, aortic diastolic pressure falls so myocardial perfusion falls. Pituitary gets ischaemic causing diabetes insipidus. So the majority of brain stem dead donors are not haemodynamically stable without intervention. 5 The hypotheralmus dysfunctions and you lose thermoregulation, and metabolism slows, as does thyroid, and you vasodilate. You become coagulopathic also. 5

Optimisation of Organ Function

You can manage patient following diagnosis of death with principle of organ optimisation. Place arterial cannulae on left if needed, place RIJ CVC if needed. These are best for how vessels are ligated at the end. 5

Give 15mg/kg of IV methylprednisolone, to minimise increase in extravascular lung water. You can continue antibiotics if needed, same for enteral feeding. Insulin may be needed for hyperglycaemia and electrolytes for disturbance. Blood transfusion may be needed too, and fixing coag abnormalities. Avoid positive fluid balance if you can for the lungs sake. 5

Minimise use of 100% O2 where able to minimise atelectasis. 5

Stop vasoactive agents if MAP persistently >95mmHg. And restart agents once the cerebral herniation process is over and hypotension starts again. Vasopressin is first line, (noradrenaline can be harmful for heart donation) 5

Maintain sodium to improve liver transplant success rate. 5

Sometimes a bit of volatile can be used to minimise hypertension, and muscle relaxants for spinal reflexes. 5

BAL is done in theatre to work out if lungs can be retrieved 5

Organ Donation After Circulatory Death

Maastricht Classification of DCD Patients:

  1. Dead On Arrival - Uncontrolled
  2. Unsuccessful Resuscitation - Uncontrolled
  3. Awaiting Cardiac Arrest - Controlled
  4. Cardiac Arrest in Brain Stem Dead Donor - Controlled
  5. Unexpected Cardiac Arrest in Critically Ill Patient - Uncontrolled 4

This could be: uncontrolled (death sudden and unexpected) or controlled (death after planned withdrawal of life sustaining treatment) donation after cardiac death. 2

There are two types of ischemia in retrieved organs - warm and cold. [

  • Warm can be split into donor and recipient warm ischaemia.
  • Donor warm starts from time of asystole until cold perfusion begins. Recipient warm starts from removal of organ from ice until reperfusion.

  • Cold ischaemia is the time in between end of donor warm and start for recipient warm. 2

  • Functional warm starts after falling below a certain threshold (Systolic < 50 or Arterial O2 Sats less than 70%) It ends when cold ischaemia starts. 2

There are time limits for amount of time acceptable for functional warm:

  • 120 mins for kidneys
  • 30 mins for liver (liver you generally are going for DBD)
  • 60 mins for lung (lungs you care more about time to re-inflation of lungs than cold perfusion)
  • 30 mins for pancreas 2

Also there are time limits between withdrawal of life sustaining therapy and onset of asystole, beyond which donation wouldn't go ahead:

  • Liver - 60mins
  • Pancreas - 60mins
  • Kidney 120 minutes (potentially up to 240 minutes) 2

There are some absolute contraindications to DCD:

  • Active invasive cancer in last three years (apart from non-melanoma skin ca, and primary brain cancer)
  • Haematological malignancy
  • Untreated systemic infection
  • Variant CJD
  • HIV disease (HIV infection is ok though) 2

Legally this is governed by Human Tissue Act 2004 2

Prior To Donation

You can do measures that facilitate donation even if not in patients best interests as long as not harm or distress. So O2 can be increased, fluid can be administered, venous cannule can be placed. Inotropes/vasopressors can be used to maintain BP but not to go higher than BP was at time decided to withdraw. Antibiotics shouldn't be used. 4

After arrest, death can be confirmed over five minutes, then family can have up to five minutes before transfer to theatre. 4

The fact that donation cant start for ten minutes is because theres no evidence of spontaneous circulation ever occuring after a period of 7 min asystole. 4

Post Mortem Interventions

You cannot do an intervention that could potentially restore cerebral circulation and function. The optimal way to prevent that is cross clamp across cerebral vessels or aortic arch. 3

Tracheal intubation for lung donation can be done, before abdominal organ retrieval. Don't restart ventilation of lungs before exclusion of cerebral circulation. But you can reinflate the lungs with a recruitment manoevre, 10 mins after arrest. 3

Sources

  1. A CODE OF PRACTICE FOR THE DIAGNOSIS AND CONFIRMATION OF DEATH. Academy of Medical Royal Colleges. 2008 ↩↩↩↩↩↩↩↩↩↩↩↩↩↩↩↩↩↩↩↩↩

  2. ORGAN DONATION AFTER CIRCULATORY DEATH. ANAESTHESIA TUTORIAL OF THE WEEK 282 11th MARCH 2013 ↩↩↩↩↩↩↩

  3. Donation after circulatory death. Organ Donation after Circulatory Death. Consensus Meeting. Department of Health, NHS Blood and Transplant. June 2010 ↩↩

  4. Donation after circulatory death. Revalidation for Anaesthetists. Kathryn Dunne, Pamela Doherty. 2011 ↩↩↩↩

  5. Physiological changes after brain stem death and management of the heart-beating donor. Joanna Gordon, Justin McKinlay. Revalidation for Anaesthetists. 2012. ↩↩↩↩↩↩↩↩↩