การให้ยาระงับความรู้สึกใน
ผูป้ ่ วย
ที่ได้รบั บาดเจ็บที่ศีรษะ
พญ. วรินี เล็กประเสริฐ
ภาควิชาวิสัญญีวท
ิ ยา
โรงพยาบาลรามาธิบดี
11/3/53
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Goals
1. To prevent secondary brain injury
2. To optimize conditions for brain
recovery & improved outcome
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Primary brain injury
•Primary damage
that occurs at the
moment of impact
or injury
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Secondary brain injury
• The production of vascular &
hematologic events that cause
reduction and alteration in CBF
leading to hypoxia & ischemia
• biochemical cascade
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Cell
death
Systemic factors contributing to
secondary brain injury
• Hypoxia
• hypotension
• Hypercapnia / hypocapnia
• Hyperthermia
• Intracranial hypertension
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Time course of neuronal death
after cerebral ischemia
Essentials of Neuroanesthesia and Neurointensive care. Gupta & Gelb, eds 2008 pp 36-42
Inflammation
Apoptosis
Minutes
Hours
6
Days
Case
scenario
• A 4 yr-old girl is brought into the ER by a
passer after being hit by a car. On arrival
she is placed in a neck collar on a spinal
board
•
•
•
•
HR 160, BP 64/30, RR 32, tympanic temp
35.5 C
Arousable to stimulation, open eyes to pain,
lethargic, age-appropriate GCS is 7
Right pupil dilated & NRTL
Distended abdomen
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Key questions
• Initial management priorities in a patient
with severe TBI
• Goals for ventilation, cerebral perfusion,
glucose
• IV access & blood products needs
• Effective treatment in lowering ICP
• Postoperative care
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Neurotrauma Risk factors
•
•
•
•
•
Advancing age
Cardiothoracic
injury
Child abuseIatrogenic
Delay in operation
Management errors
Technical mistakes
Alcohol abuse
Shock
Delay in transfer
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Developmental considerations in
Pediatric Neurotrauma
 Lower autoregulatory reserve
• (<2 yrs)
 Larger percentage of CO directed to the brain; risk of unstable
hemodynamics
 Larger head-to-torso ratio, acceleration-deceleration injuries caused more
diffuse brain injury
 Open fontanels & cranial sutures ;more compliant intracranial
space
• Mass effect of a slow growing tumor & insidious hemorrhage is masked !
•
Soriano SG. Update on CNS injury: Mx of the pediatric patient,ASA RCL 2008
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Developmental considerations in
Pediatric Neurotrauma (II)
Infants & toddlers are more vulnerable to
cervical spine injury
SCIWORA (Spinal Cord Injury Without
Radiographic Abnormality) in up to 70% of
children
•
with C-spine injury
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Initial management
•Priorities in trauma care
• Primary survey
•“ Basic evaluation to recognize &
manage life-threatening injuries “
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ABCDE algorithm
• Immediate management
100% oxygen administration
Standard monitoring: EKG,
NIBP,SpO2 , EtCO2
Rapid sequence intubation, using
in-line stabilization
Mild hyperventilation
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Attempted suicide with a nail
gun
Presented by Dr.Nguyen from Albany Medical
Center, at the 2006 PGA
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After immediate stabilization, what
next?
Secondary survey (head to toe
examination)
Establish definite IV access &
•
A-line, + CVP line
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CT scan: Left temporal extradural
hematoma
• The neurosurgeon requested to
evacuate hematoma
What is your anesthetic plan?
How many IV lines?
What is your choice of IV fluid?
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Traumatic brain injury
• Consider associated injury in a
multiple trauma patient
• Cerebral autoregulation is variably
impaired
• Brain parenchyma is a rich source of
tissue factor; DIC may be induced
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Preanesthetic assessment of TBI
• Airway (C-spine)
• Breathing
• Circulation
• Associated injuries
• Neurological status (GCS)
• Preexisting chronic illness
• Circumstances of the injury:
- time of injury
- duration of unconsciousness
- associated alcohol /drug use
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การดูแลระบบไหลเวียนเลือด
•Cerebral hemodynamics
CPP = MAP - ICP
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Cerebral perfusion
pressure
50
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Effects of intraoperative hypotension on
outcome in patients with severe head injury
Severe HI
Mortality rate
(%)
Hypotension
82
Normotension
52
• Pietropaoli, et al. J of Trauma
1992;33;403-7
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Hypovolemia
• Blood loss
• Diuresis
• Decreased intake
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Hypotension
&
Cerebral
ischemia
Clinical goals
• Maintain normovolemia &
hemodynamic stability
• Maintain adequate plasma colloid
osmotic pressure
• Enhance microvascular blood flow
• Guarantee adequate tissue oxygen
transport
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ScScanning electron micrographs of RBCs
isolated from stored blood on days 1, 21, and 35
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Transfusion in neuroanesthesia
• The best scenario: coming to the OR with
normal Hb level & losing little blood
• Minimizing unnecessary loss
• Maximizing brain oxygen supply & demand
prior to transfusion
• Good monitorings !!
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Blood glucose control
•Target between 140-180 mg% on the
basis of the lack of proof of the
efficacy of tight control levels in
patients with CNS injury & on the real
risk of hypoglycemic injury
• Intraoperative brain protection; physiologic
management . Patel PM. ASA RCL 2009
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Where do I keep the PaCo2?
•No straight answer
•Recent evidence for the effects of
hyperventilation from PET
• “ Reducing PaCO2 from 35-40 mmHg to 30
mmHg caused a 2.5 fold increase in the
volume of brain having flow ≺ 10 ml/100
gm/min “ Crit Care Med 2002;30:1950-9
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Effects of anesthetic
agents : May not be the crucial aspect !!
From IHAST database; use of nitrous oxide was associated
with an increased risk for the development of DIND (OR
1.78, 95% CI 1.08-2.95; p=0.025).
However, there was no evidence of detriment to
long-term outcome (3 mths after sx).
Anesthesiology 2009;110,56-73
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Effectes of inhalation agents
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Intracranial hypertension therapy
•
•
•
•
•
•
Head up position & avoid venous
drainage obstruction
Adequate ventilation
Diuretics
Reduction of systemic hypertension
Drainage of CSF
Release of hematoma
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Temperature
control
• Hypothermia treatment for TBI : a
systematic review and meta-analysis.
J Neurotrauma 2008;25:62-71
Favorable neurological outcome (
RR 1.91; 95% CI 1.28, 2.85) BUT ......
Increases risk of pneumonia
( RR 2.37;95% CI 1.37-4.10)
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Postoperative care
•
•
•
Maintain a good perfusion
pressure at all times,
preferably ≻ 65 mmHg
Target glucose 140-180
mg% with frequent
monitoring
Normoventilation with
judicious use of
hyperventilation (if at all)
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Thank you
for
your
attention !!
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