Using Data Visualization in Public Health Communications
Brain death
1. BRAIN DEATH
By: Riahialam M , MD
Anesthesiology and Critical Care Department
Shiraz University of Medical Sciences
Reference: Uptodate v19.2
3. Prerequisite
Define Cause
Imaging
R/O Electrolyte or Ph disturbance, endocrine
problems, severe shock
R/O Intoxication or drug poisoning
R/O False Positive: Locked-in syndrome, GBS
T>= 36C
SBP>=100 even by vasopressour infusion
4. Neurologic Exam Deep Coma
No Motor Response
No Pupil Response To Light (Pupil size 4-
9 mm)
Neg. Corneal Reflex
Neg. Occulovestibular Reflex
Neg. Jaw Jerk
No Cough during ETT Suction
Neg. sucking or Rooting Reflex
Apnea test
7. Movement present in brain death
Some of spinal cord or peripheral nerve
Movement in facial nerve region,
Finger Flexion,
Tonic Neck reflex (with flexion in neck some
movement appear in body like shoulder add. Elbow
flex. , Pron. Or supine. Wrist, flex. of trunk,
LAZARUS sign),
Triple flexion in hip, ankle & knee after foot
stimulation like babinski sign,
Some opisthotonic movement in trunk,
Pos. Abd. Superfascial or deep Reflexes,
Undulating Toe Sign,
Pos. pronation extension reflexes upper limb
9. Caloric test
T difference between the body and the injected
water creates convective current in the
endolymph of the horizontal semicircular canal
Warm Water (>=44°C) endolymph in the
ipsilateral horizontal canal rises, causing an
increased rate of firing in the vestibular
afferent nerve. This situation mimics a head
turn to the ipsilateral side. Both eyes will turn
toward the contralateral ear, with horizontal
nystagmus to the ipsilateral ear.
Cool Water (<=30°C), the endolymph falls within
the semicircular canal, decreasing the rate of
vestibular afferent firing. The eyes then turn
toward the ipsilateral ear, with horizontal
nystagmus (quick horizontal eye movements) to
the contralateral ear.
10. Caloric test
COWS = Cold Opposite , Warm Same
(Fast direction nystagmus)
In comatose patients with cerebral
damage, the fast phase of nystagmus
will be absent .
If both phases are absent, this suggests
the patient's brainstem reflexes are
also damaged .
13. Apnea Test
Done after other criteria: Core temperature ≥36ºC,
SBP≥100 mmHg, eucapnia (PaCO2 35 to 45 mmHg),
absence of hypoxia, and euvolemic status
O2 100% in 10 min , PEEP 5, till PaO2=200 or PaCo2>=40 ,
when SaO2>95 ABG is done
Pt Disconnected from M.V , O2 6 lit/min administrated
with Canola at level of carina or T-piece or CPAP
10 cmH2o with O2 12 lit/min
PaCO2 >= 60 mmHg or 20 mmHg above baseline
and PH<7.28 with no Respiratory effort, in 8-
10 min
15. Note
Apnea Test Not Valid for : chronic ↑PaCo2,
Cervical Spine Injuries,
Test discontinued: If SBP<90 or Sao2<85
for 30sec, or Cardiac Arrhythmia appears.
Another choice for these pt. is CPAP.
New method is M.V with O2+CO2 3.5% ,
Fr:4/min, and observe pt respiratory effort
detected by respirator, pressure trigger is
better
16. Repeat test?
Newborn 7d-2m >>> 48hr later
Infant 2m-1y >>> 24hr later
Child 1y-18y >>> 12hr later
Adult >>> 6hr
Resuscitated or Hypoxic
encephalopathy >>> 24hr later
18. Note Resuscitated after cardiac arrest, we recommend
observation for at least 24 hours from the time of the
arrest, as spontaneous improvement in brainstem
reflexes can occur hours after cardiac arrest.
In patients received induced hypothermia, the recovery
time may be further extended, as some motor and
brainstem reflexes may recover after being absent for
three days.
Perform an ancillary test of brain blood flow with such
patients;
Electrophysiologic parameters may also be affected by
induced hypothermia.
2010 American Academy of Neurology guideline update
published in found insufficient evidence to determine a
minimally acceptable observation period.
19. Ancillary Tests
When the cranial nerves cannot be adequately
examined
When neuromuscular paralysis is present
When heavy sedation is present
When the apnea test is not valid (high carbon
dioxide retainers) or cannot be completed
When confounders render the clinical examination
unreliable, e.g., multiple organ failure and the
presence of a sedating or paralyzing drug that may
be very slow to clear
To shorten the duration of the observation period
Infants <1 year; two positive tests are required for
those <2m.
20. Ancillary Tests
EEG
Evoked potentials — Somatosensory evoked
potentials (SSEPs) and brainstem auditory
evoked potentials (BAEPs)
Brain blood flow —Transcranial Doppler, MR
angio, CT angio, Nuclear medicine, 4vessel
cerebral angio is the traditional "gold
standard"
Other tests — The atropine test examines the
HR response to intravenous injection of 3 mg
atropine. An increase in HR of <3%supports
the diagnosis of brain death
22. Brain Death Mimics
Locked-in syndrome
Hypothermia
Drug intoxication
Guillain-Barré syndrome
23. Prognosis
In adults, there are no published reports
of recovery of neurologic recovery after a
diagnosis of brain death as outlined
above
Brain ischemia leads to sympathetic
nervous system collapse leading to
vasodilation and cardiac dysfunction
Pulmonary edema and diabetes insipidus
are frequent early consequences of brain
death and may also precipitate
cardiopulmonary failure
25. Prognosis
In one series, all 73 patients meeting the
clinical criteria for brain death suffered
cardiac asystole despite full
cardiorespiratory support; 97 percent died
within seven days
One case series of 175 patients surviving
longer than one week after diagnosis of
brain death challenges this tenet. In this
series, 80 patients survived two weeks, 44
survived four weeks, 20 survived two
months, and seven survived six months.
Those with long survivals were very young
(two newborns).