Brain death declaration in children

Dr Lokesh LingappaConsultant Paediatric Neurologist

Rainbow Children’s Hospital and Perinatal Centre, Hyderabad

outline

• Limitations of current guidelines• Testing process• Are there differences adult/pediatric • Problems of newborn testing• Fallacies in intepretation of signs and testing

results

Key message

• The diagnosis of brain death should remain a clinical one to be made at the bedside by knowledgeable physicians who, in concert with grieving families, make the most agonizing of all life’s events (the death of a child) as bearable as possible for all concerned.

• Freeman JM, Ferry PC. New Brain Death Guidelines in Children

Understanding limitations of pediatric brain death guidelines

• Guidelines are 20 years old• Relied heavily upon EEG testing• Guidelines did not specifically address the trauma

population• Guidelines were based upon limited clinical experience

at the time of publication• Guidelines were based upon age criteria• No guidelines for neurologic death in neonates• Waiting times have never been validated

History

• Determination of cause of death is necessary to ensure the absence of treatable or reversible conditions (ie, toxic or metabolic disorders, hypothermia, hypotension, or surgically remediable conditions).

Primary requirement

• Irreversibility of brain function cessation is recognized

• Cause of coma is established and is sufficient to account for the loss of brain function

• Possibility of recovery of any brain function is excluded

• Cessation of brain function persists for an appropriate period of observation or trial of therapy

Diagnostic criteria

• Cessation of all brain function is recognized. • Cerebral functions are absent (ie, unresponsiveness) • Brainstem functions are absent: 1. Pupillary light reflex 2. Corneal reflex 3. Oculocephalic/oculovestibular reflex 4. Oropharyngeal reflex 5. Respiratory (apnea using an accepted apnea

testing procedure)

Confounding factors

• Complicating conditions are excluded • Drug and metabolic intoxication • Hypothermia • Circulatory shock• The patient has been monitored for an

appropriate observation period

Brainstem testing

Without confirmatory tests

• 12 hours when the etiology of the irreversible condition is well established

• 24 hours for anoxic injury to the brain

With confirmatory tests

• EEG: Irreversible loss of cortical functions with ECS, together with the clinical findings of absent brainstem functions, confirms the diagnosis of brain death.

• CBF: Absent CBF demonstrated by radionuclide scanning or intracranial 4-vessel cerebral angiography in conjunction with clinical determination of absence of all brain function for at least 6 hours is diagnostic of brain death

Age dependent Observation period

age Hours between 2 examination

Recommended number of EEGs

7 days to 2 months 48 2

2 months to 1 year 24 2

Beyond 1 year 12 None needed

Brain death and organ donation

Rainbow data 2009 29/79

Head injury 3

Near Drowning 2

CNS infection 9

Asphyxia 1

Metabolic disorders 9

Cerebrovascular disorders 1

Miscellaneous 4

Neonatal brain death

Neurologic death in the neonate

• “Brain death can be diagnosed in the term infant, even at less than 7 days of age. An observation period of 48 hours is recommended to confirm the diagnosis. If an EEG is isoelectric or if a CBF study shows no flow, then the observation period can be shortened to 24 hours.”

• Ashwal. Brain death in the newborn. Clinics in Perinatology 1997;24:859-879

Brain death in the neonate

• The younger the child, the more one needs to exercise caution in determining brain death

• A second opinion from a colleague in pediatric critical care or someone who is specialized in the neurosciences is reasonable

• Physical examination criteria may require a longer observation time based upon mechanism of cerebral injury

• Use of ancillary test may be beneficial, but may also confuse the issue in the neonate

• The absence of any form of repetitive, sustained, purposeful activity on serial examinations must be documented; likewise, brain death must be differentiated from other states of unconsciousness, such as the vegetative state

preterm and term neonates

• several of the cranial nerve responses are not fully developed.

• pupillary light reflex is absent before 29 to 30 weeks’ gestation,

• oculocephalic reflex may not be elicited before 32 weeks’ gestation

• Term and preterm infants are difficult to examine because their smallness makes it technically difficult to assess

Preterm and neonate

• Assessment of pupillary reactivity can be compromised difficulties in gaining access –incubator, by corneal injury, retinal hemorrhages, and other anatomical factors (swelling or partial fusion of the eyelids)

• smaller size of the pupils in newborns- make assessment of the loss of pupillary reactivity troublesome

Preterm and neonate

• Assessing the caloric response adequately more difficult in neonates with a small external ear canal;

• both the oculocephalic (doll’s eye) and oculovestibular (caloric) reflex should always be examined

• corneal reflex- easiest brain stem reflex to examine in neonates and infants, it is often the least reliable

• Contact irritation, dehydration and maceration of the cornea, use of lubricant drops, and use of analgesic medications often adversely affect tactile sensory information

MRI and CT of Neonates -HIE

Neuroimaging in Decision process

Neonatal CT Follow up CT brain

ANCILLARY TESTING

Considerations when diagnosing brain death in children

• Many times the cause of the child’s neurologic demise is known

• Based upon presentation and examination many times we know that there will be no hope for survival or if the child does survive, the outcome will be dismal

• The waiting period may be extended or decreased depending upon social and family related issues

Ancillary testing

• Ancillary test that may aid in the diagnosis of brain death

• EEG• Cerebral angiography• Radionuclide Scans• Brainstem evoked responses• Doppler sonography

Ancillary testing

• Ancillary tests may aid in the diagnosis of brain death– Ancillary tests can provide additional information to

help confirm brain death in situations where clinical examination and apnea testing are not feasible or cannot be completed because of undue circumstance

– Facial injury– Acute lung injury– Cardiovascular instability

Ancillary testing

Ancillary tests are not mandatory• Ancillary tests may provide another layer of

comfort to the physician who is uncomfortable declaring brain death on clinical exam alone

• Ancillary tests may reduce observation periods thus increasing potential for retrieving viable transplant tissue

• Ancillary tests may also delay or prolong observation period

Recommendation for EEG

• the American Electroencephalographic Society retrospectively surveyed 1665 patients with electrocerebral silence (ECS), that is, no evidence of brain electrical activity greater than 2 µV between electrode pairs placed at a distance of 10 cm or more, who were in various levels of coma

• Only 3 of the 1665 patients recovered cerebral function

EEG in infants and children

• shorter interelectrode distances;• external artifacts in newborn ICUs and PICUs;• Distances between the heart and the brain, making the

electrocardiographic contribution disproportionately large

• reduced amplitude of cortical potentials in preterm and term neonates

• longer duration of the effect of depressant medications• greater tendency for suppression burst patterns in

infants with neurological disorders

Need for EEG

• Two cases of acute inflammatory demyelinating polyradiculoneuropathy have -at satisfied the clinical criteria for brain death but had preserved EEG activity

• EEG has an important role in the confirmation of brain death in such cases

Electrocerebral silence

EEG contd

• EEG patterns may show low-voltage theta or beta activity or intermittent spindle activity

• Such activity in functionally dead brains may persist for days

• Data from several studies indicate that the initial EEG in brain dead children is isoelectric in 51% to 100% of patients (mean 83%).

• In most children who initially have EEG activity, follow-up studies usually show evolution to ECS

• Typically, when the initial EEG

EEG contd

• ECS may occur soon after an infant or a child has had a cardiac arrest.

• In infants in whom the initial EEG (typically obtained 8-10 hours after cardiac arrest) showed ECS, a repeat study 12 to 24 hours later may show diffuse low-voltage activity

• Most of these infants die of complications - acute catastrophic injury; the remaining survivors permanent vegetative or minimally conscious state

EEG and drugs

• children, the most common medications causing reversible loss of brain electrocortical activity include barbiturates (eg, phenobarbital), benzodiazepines, narcotics, and certain

• intravenous (thiopental, ketamine, midazolam) and inhalation (halothane and isoflurane) anesthetics.

• Data from a study in 92 children indicated that therapeutic levels of phenobarbital (ie, 15-40 μg/mL) do not affect the EEG

Need for repeat EEG

• Data on 37 of 53 brain-dead newborns in whom EEGs were performed

• ECS (n = 21), very low voltage (n = 13), burst suppression (n = 1), seizure activity (n = 1), and normal activity (n = 1).

• Almost all patients whose first EEG showed ECS had ECS on the second study, and most patients who did not show ECS on the first EEG did so on a repeat study

• The data suggest that only a single EEG showing ECS is necessary to confirm brain death, provided the results of the examination remain unchanged

Cerebral blood flow studies

• The absence of CBF in brain death is due primarily to low cerebral perfusion pressure and secondarily to release of vasoconstrictors

• from vascular smooth muscle

HMPO SPECT

Cerebral blood flow-neonatal issues

• Newborns have patent sutures and an open fontanel, increases in ICP after acute injury are not significant

• cascade of herniation from increased ICP and reduced cerebral perfusion is less likely to occur in newborns

• Brain death can be diagnosed in newborns (even when younger than 7 days) if physician is aware of the limitations of the clinical examination and

laboratory testing

Institutional Guidelines

• Does a policy regarding declaration of death exist in your institution? Policy should provide guidelines allowing flexibility and individuality for each child and their family

• Decisions regarding determination of brain death should be left to the physician’s discretion within evolving standards of medical care

• Who declares brain death in your institution? • Concentrate your efforts on educating these individuals and

involve them in the establishment of institutional guidelines

Take home messages

Neurologic death occurs in children • There are no unique legal issues in determining neurologic

death in children • Neurologic death is a clinical diagnosis• Ancillary studies are not mandatory, however they can assist in

determining neurologic death in certain situations • Ancillary studies can reduce or prolong the recommended

observation period• Observation periods have never been validated and are meant

to serve as guidelines only• Neurologic death can occur and be diagnosed in infants less

than 7 days of age

Thank you

• One Class III study of 144 patients pronounced• brain dead found 55% (95% confidence interval• [CI] 47–63) of patients had retained plantar reflexes,• either flexion or “stimulation induced undulating toe• flexion.”22 Another study documented plantar flexion• and flexion synergy bilaterally that persisted for• 32 hours after the determination of brain death.23

ApneaTesting

• Absence of a breathing drive.• Prerequisites: 1) normotension, 2) normothermia,• 3) euvolemia, 4) eucapnia• (PaCO2 35–45 mm Hg), 5) absence of• hypoxia, and • Procedure:• • Adjust vasopressors to a systolic blood• pressure 100 mm Hg.

• Neurology 74 8, 2010

Preoxygenate for at least 10 minutes with 100% oxygen to a PaO2 200 mm Hg

• 10 breaths per minute- eucapnia• Reduce PEEP to 5 cm H2O (oxygen desaturation

with decreasing PEEP may suggest difficulty with apnea testing).

• SpO2> 95%, obtain a baseline blood gas (PaO2, PaCO2, pH, bicarbonate, base excess)

• Disconnect the patient from the ventilator

Preserve oxygenation (e.g., place an insufflation catheter through the endotracheal tube and close to the level of the carina and deliver 100% O2 at 6 L/min).

• Look for respiratory movements - 8–10 minutes. • Abort if systolic blood pressure decreases to 90 mm Hg.• Abort if oxygen saturation measured by pulse oximetry

is 85% for 30 seconds.• Retry procedure with T-piece, CPAP 10 cm H2O, and

100% O2 12L/min

• If no respiratory drive- repeat blood gas after approximately 8 minutes.

• • If respiratory movements are absent and arterial PCO2 is 60 mm Hg (or 20 mm Hg increase in arterial PCO2), the apnea test result is positive

• • If test is inconclusive- patient is hemodynamically stable, it may be repeated for a longer period of time (10–15 minutes)

• after the patient is again adequately preoxygenated.

Take home messages

• Diagnosing brain death is not different in children as compared to adult

• Newborn 34 week and above can be reliably daignosed to have brain death within first week of life

• Most newborn withdrawal of care is based on future poor neurologic outcome rather than brain death

• Most common ancillary testing required is EEG