• Apnea : clinically confirmed through the
• performed only if the first 2 criteria
for brain death(irreversible coma and
absence of brainstem reflexes) are already
• Procedure : Preoxygenate the patient with
100% oxygen for approximately 10 min
adjust ventilation to achieve a PCO2 of
about 40 mm Hg
• During the test, oxygenation is maintained
on CPAP and 100% oxygen by means of
the ventilator circuit or a resuscitation bag
such as a Mapleson device,
• Child is assessed for breathing efforts
through observation and auscultation.
• A blood gas sample is obtained
approximately 10 min into the test and
every 5 min thereafter until the target
PCO2is surpassed; ventilatory support is
resumed at that time.
• If at any point during the test the patient
becomes hypoxic or hypotensive, the test
is aborted and ventilatory support is
• Absence of respiratory efforts with a
PCO2 > 60 mm Hg or more than 20 mm Hg
above an elevated baseline value is
consistent with brain death.
Varies by age :
• 7 days- 2 mo:
2 examinations separated by at least 48 hr.
• 2 mo - 1 yr :
2 examinations separated by at least 24 hr
• >1 yr :
12-hr observation period between exams.
If the cause of the coma is hypoxicischemic brain injury and the first exam is
performed shortly after the insult, a period
of at least 24 hr is recommended before
the second exam.
A second exam is not needed if a
nuclear medicine cerebral flow scan
demonstrates absence of CBF.
• All children <1 yr of age.
• Where clinical exam is impossible to perform
or the results are suspected to be unreliable.
• The 2 most commonly used confirmatory
tests are :
- EEG and
- Studies to confirm the absence of CBF
eg. nuclear medicine cerebral flow scans.
• An EEG showing electrocerebral
silence over a 30-min supports the
diagnosis of brain death.
• Advantages : wide availability and low
• Disadvantages : artefact in the presence
of drugs like barbiturates
• Nuclear medicine cerebral flow scan :
Intravenous injection of a
radiopharmaceutical agent followed by
imaging of the brain
Absence of uptake in the brain
demonstrates absence of CBF and is
confirmatory of brain death
Advantages : low risk, not affected by
1 Etiology and irreversibility of the coma
2 Absence of confounding factors: hypothermia,
hypotension, hypoxia, significant metabolic
derangement, significant drug levels
3 Absence of motor response to noxious stimulation
4 Absence of brainstem reflexes: pupillary light reflex,
oculocephalic/oculovestibular reflex, corneal
reflex, cough and gag reflex
5 Absence of respiratory effort in response to an
adequate stimulus; blood gas values should be
documented at the beginning and end of the
• supportive care may continue for hours to
days as the family makes decisions about
potential organ donation and comes to
terms with the diagnosis.
• Refereance –
Nelson Textbook of Pediatrics 19 th edition.