Technical Assistance for Alignment in Organ Donation- EuropeAid/131052/D/SER/TR Key Points in Brain Death Diagnosis Clinical aspects and Confirmation Francesco Procaccio ISS – CNT - Rome Neuro Intensive Care Unit University City Hospital, Verona - Italy What is Brain Death? Total Brain Infarct 2 BD Definition Brain Death is the irreversible loss of capacity for consciousness combined with the irreversible loss of all brainstem functions including the capacity to breathe. The Canadian Neurocritical Care Group, 1999 Certainty of death: Irreversibility Brain Death or Brain Dying? Death is a process Neurological functions must have ceased irreversibly Karnice-Karnicki, 1896 F Procaccio 2012 (Brain) Death “Irreversible loss of all cerebral functions” Brainstem death 6 Why Brain death is the only death ? Pathophysiological reasons 7 When a person is dead? Definitive, irreversible total damage of the brain Cerebral functions are totally lost Due to two different mechanisms: 1) Respiratory and circulatory arrest causing secondary irreversible damage of brain (non Heart Beating cadaver) 2) Devastating cerebral lesions which cause total irreversible damage of the brain (Brain Death – Heart Beating cadaver) 8 Definition of death (Universal death) Simple uniform reliable concepts & definitions may increase public confidence and trust 9 Capron , May 2012 Montreal Forum Why only Brain death is death ? Heart, Lung, Liver, Kidneys etc. are vital organs but can be supported by technology or replaced by transplantation. except The Brain 10 Who may become brain dead ? Only patients with acute cerebral lesion under mechanical ventilation in ICU Brain injury – Cerebral Hemorrhage Ischemic Stroke – Brain Tumour Anoxia – Cerebral Infection etc. Determination of death by neurological criteria Determination of Death by Neurological criteria EEG CBF Clinical REFLEXES “All the cerebral functions are irreversibly lost” 14 Total Brain Infarct Absence of cerebral blood flow Death 15 Harvard Criteria - 1968 The Neurological Standard 16 Wijdicks E. N Engl J Med 2001 17 Brain Death Diagnosis Milestones 1. The etiology of the brain lesion is known 2. Exclude all potential confounding factors 3. The neurological examination is complete and all clinical criteria are fulfilled 18 Etiology 19 NMR 20 Clinical examination Prerequisites • • • • • • Etiology must be known Imaging of irreversible cerebral damage Temp. >32 °C (“Normal” BP – SO2 – Na+) Exclusion of medical confounding factors Exclusion of drug effects on CNS Exclusion of drug effects on clinical exam (muscle relaxant agents, atropine etc.) 22 The Brainstem 23 Brainstem reflexes: pathways Oculocephalic Painful stimuli Oculovestibular Corneal Light response Tracheal VI V III II VII VIII X XI 24 25 Pupillary response to light Methodology & clinical experience 26 APNEA TEST Absence of respiratory drive 130 78 23 130 98 PaCO2 > 60mmHg 100% Oxygen 27 Why brain dead patients may move ? Spinal reflexes in Brain Death Brain infarct Spine without superior control 1 Spinal Shock 2 Spinal function recovery 3 Hyperexcitability 29 Are there factors that may cause unreliable brain death diagnosis? CONFOUNDING FACTORS Severe derangement in temperature, blood pressure, oxygenation, electrolytes, glusose, cortisol, T4) Drugs (sedative/anesthetic - barbiturates ! – muscle relaxants ) Facial trauma – Cranial nerves lesions 31 Facial Trauma 32 If potentially confounding factors may be present confirmatory tests must be used The absence of cerebral perfusion is a simple, clear, acceptable criteria, easily to be understood and demonstrated. Cerebral angiogram. Arch injection Wijdicks, 2001 35 36 Trans Cranial Doppler TCD Brain Death patterns 37 Angio-CT scan Girlanda R BD standard – no confounding factors F Procaccio 2012 Persistence of cerebral blood “flow” after brain death Flowers WM et al. Southern Medical Journal 93:364,2000 • Decompressing fractures • Ventricular shunts • Reperfusion (post-anoxic !) • Decompressive Hemicraniectomy 39 Possible Pitfalls in BD diagnosis 1. the BD declared patient is not Dead zero mistake must be ensured 2. the BD person is not BD declared silent BD – Death is not equal - missing PODs F Procaccio 2012 Mimicking Disorders • Hypothermia • Barbiturates • Acute poisoning • Endocrine crisis (glucose – cortisol – T4) • neurological diseases 41 “Neurological” conditions that may be confused with Brain Death • • • • • • Locked-in syndrome Guillain-Barré syndrome Demyelinating conditions Post-anoxic coma Brainstem encephalitis “Medulla man” 42 The Medulla Man 43 Wijdicks E. J Neurol Neurosurg Psych 2001 F Procaccio 2012 Post-anoxic BD swelling 6 hours “flow” Neuro ICU, Verona - 2005 45 46 Possible Pitfalls in BD diagnosis 1. the BD declared patient is not Dead zero mistake must be ensured 2. the BD person is not BD declared F Procaccio 2012 Brain Death Declaration Certain diagnosis plus Legal procedures 49 Clinical Diagnosis simple and reliable Must be complete methodical rigorous 50 Deceased Organ Donation Dead Donor Rule Dying process • Threshold of irreversibility • Clinical standard • Confirmatory tests Death determination (diagnosis) (legal) Death declaration • Adherence to guidelines • Legal procedures • The moment of Death 51 Death determination by neurological criteria Brain death diagnosis (clinical criteria) Coma Brainstem reflexes + apnea etiology x Mandatory EEG Mandatory CBF x no x CBF In Defined Condition s children x x All pts or only potential donors? all other >24hrs anoxic BD declaration (legal procedures) Observation period N° MD Repeated clincial tests 6 hrs 3 2 Country: Italy Repeated EEG 2 Repeated CBF Children no Law –Decree ? National Guidelines ? x All pts Or only Potential Donors? all !x! !x! Italy 52 Timing in Death declaration ICU Admission 1 Vegetative Storm (coning) BD criteria 2 Patient treatment Brain Death Declaration observation 3 4 Death 53 Common Principles for present/future ? Citizens equal in death: Death declaration independent from organ donation Clear, simple and acceptable definitions, criteria and procedures in death diagnosis A «Universal death» independent from clinical and (new) technical aspects Clear legal procedures for death declaration 54 Suggestions 1. Treating physicians (Intensivists!) should be more involved in BD diagnosis and potential donor identification. 2. BD Pathophysiology based guidelines should guide BD diagnosis and donor treatment. 3. Law and decrees should have (few) technical details aimed to BD (legal) declaration 55 Key factors 1. Specific education and common language are needed. 2. Quality of critical care may facilitate BD diagnosis. 3. The probability of success in organ donation reflects the capacity of declaring brain death in all the patients fulfilling BD criteria. 56 Case study Reversible Brain Death 57 A 55-yr-old man presented with cardiac arrest preceded by respiratory arrest. Cardiopulmonary resuscitation was performed, spontaneous perfusion restored, and therapeutic hypothermia was attempted for neural protection. After rewarming to 36.5°C, neurologic examination showed no eye opening or response to pain, spontaneous myoclonic movements, sluggishly reactive pupils, absent corneal reflexes, and intact gag and spontaneous respirations. Day 1 Facial Myoclonus Over 24 hours, remaining cranial nerve function was lost. The neurologic examination was consistent with brain death. Apnea test and repeat clinical examination after a duration of 6 hrs confirmed brain death. Death was pronounced and the family consented to organ donation. Are there factors that may cause unreliable brain death diagnosis? Twenty-four hrs after brain death pronouncement, on arrival to the operating room for organ procurement, the patient was found to have regained corneal reflexes, cough reflex, and spontaneous respirations. The care team faced the challenge of offering an adequate explanation to the patient's family and other healthcare professionals involved. 63 Would you consider propofol/fentanyl a potential confounding factor at hour 80 ? 1) Yes 2) No 3) maybe 66 The ideal practice is to use confirmatory tests only if necessary to confirm the clinical examination. Physicians should not go far as to place blind faith in machinery and the clinical diagnosis remains a sacrosant principle. EFM Wijdicks, 2001 67 Is an ancillary test 1) Useful 1) Mandatory 1) Unreliable 68 170 Hypothermia Sedation SEPs F Procaccio 2012 195 NMR 200 CBF CCA 202 ventilation withdrawal Operating room 1°- 2° clinical exam + apnea test Although the reversal was transient and did not impact the patient's prognosis, it impacted his eligibility for organ donation and cast doubt about the ability to determine irreversibility of brain death findings in patients treated with hypothermia after cardiac arrest. CONCLUSIONS: We strongly recommend caution in the determination of brain death after cardiac arrest when induced hypothermia is used. Confirmatory testing should be considered and a minimum observation period after rewarming before brain death testing ensues should be established.