Download MBBS Neuroanaesthesia PPT 5 Perioperative Management Of Traumatic Brain Injury Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Neuroanaesthesia PPT 5 Perioperative Management Of Traumatic Brain Injury Lecture Notes

Perioperative Management of

Traumatic Brain Injury

Introduction

? "a blow to head or a penetrating head injury

that disrupts the function of brain"

? One lakh lives are lost every year due to TBI in

India

? Nearly 95% trauma victims do not receive

optimal care during `Golden Hour' period

? Among them 30% of lives could be saved if

quality care were available to them sooner
Global data on TBI

? 50 million injured every year
? Estimated deaths ? 1.2 million
? Global mortality: 97/1,000,000
? 70 % fatalities (8,500,000) under 45 years of age

? WHO Research Predicts by 2020:
? 80 % increase in developing countries
? 147 % increase in road traffic accidents (RTA)

deaths in India/Rajasthan

Indian data on TBI

? 60% of all TBI caused by RTA
? Fatality rate: 70 per 10,000 vehicles
? 25X higher than in developed countries
? One person dies in India every 6 - 10 mins; will

be every 3 mins by 2020

? "vulnerable road users":
- Pedestrians (25 %),
- Motorcyclists (17 %),
- Four-wheel vehicle operators (15%),
- Pedal cyclists (10 %).


? By 2050, India will have the greatest number

of automobiles on the planet, overtaking the

United States.

? A study conducted by CRRI-
? Increase traffic congestion in Delhi might

actually have resulted in fewer accidents over

last year.
Pathophysiology of Traumatic Brain Injury

TBI

10 Injury to brain

ICP

Inlammation/edema/excitotoxicity

ICP CPP

Secondary injuries to brain

Secondary insults contributing to

hypoxic/ ischemic brain damage

Systemic

intracranial

Hypoxemia

Hematoma

Hypotension

Raised ICP

Anemia

Seizures

Hypo/hyper carbia

Infection

Pyrexia

Vasospasm

Hyponatremia

Hypo/hyper glycemia
Importance of perioperative period

? Most of the poor outcomes after severe head injury

are related to presence of pre-hospital secondary

insults

? Perioperative period provides an opportunity to

continue and refine ongoing resuscitation and to

correct pre-existing secondary insults

? Perioperative period may be a window to initiate

interventions, that may improve the outcome of TBI

Does the "Golden Hour" After Injury

Really Matter?
Golden hour

? A traditional dogma- trauma patients should

reach the hospital and to be treated with in one
hour of injury

? First described by R Adams Cowley in 1975
? Several studies have suggested a decrease in

mortality when trauma patients reach definitive
care during the Golden Hour, but recent research
demonstrates no link between time and survival.

? Although prehospital time should be minimized, the

use of lights and sirens and air transport entail costs
and risks that must be weighed against possible
benefit for each patient.

? Also, for really seriously injured patients, arrival at

the right place (a Level I trauma center) is probably
much more important than the out-of-hospital time.

- Newgard CD et al. Ann Emerg Med 2015 Jan 14.
Goals of perioperative management of

TBI

? The key elements of TBI management-
?Early resuscitation
?Hemodynamic optimization
?Emergent surgical evacuation of mass lesion
?Control of ICP
?Support of CPP
?Optimization of physiological milieu

Prehospital Management

? Emergency therapy should begin at the site of

accident and in the ambulance

? EMS providers- should be trained to follow an

established algorithm for assessment and
treatment of TBI

? The first priority is initiation of basic

resuscitation protocol, prioritizing the ABCs

? Severely head injured patient to be directly

taken to level I trauma centre- BTF
Emergency Department Management

? The initial assessment and stabilization-

achieved as soon as the pt arrives in the ED

? Evaluation of ABCs
?Rapid assessment of neurological status,

pupillary response

?Associated extra cranial injuries
?Evaluation of anemia/ coagulopathy/ glycemia
?Adequate vascular access
? Non contrast CT scan is radiological procedure

of choice

Airway management

? Airway management in TBI is complicated-
? urgency of situation
?Uncertainty of cervical spine status
?Uncertainty of airway
?Full stomach
?Intracranial hypertension
?Uncertain volume status
Technique - Best Practices

? Choice of technique depends upon-
?Urgency /Individual expertise/ Available

resources

? Generally incorporates RSI with cricoid pressure

and MILS

? Newer airway devises, particularly

videolaryngoscopes, may be useful in difficult

airway scenarios

? Nasal intubation- avoided in patients with base of

skull fracture, severe facial fractures or bleeding

diathesis.

? Appropriate pharmacological selection is

important

? Sodium thiopental, etomidate and propofol

decrease cerebral metabolic rate for oxygen

(CMRO2) and attenuate increases in ICP with

intubation

? Propofol & Thiopental may cause CVS depression

leading to hypotension

? Etomidate- hemodynamic stability during

induction? Adrenal insufficiency

? The choice of muscle relaxant for RSI is

succinylcholine or rocuronium

? Succinylcholine may contribute to increased ICP

the clinical significance?
Anesthetic Management

? The major goals of anesthetic management of

TBI are-

?To facilitate early decompression
?Provide adequate analgesia and amnesia
?Treat intracranial hypertension and maintain

adequate cerebral perfusion

?Provide optimal surgical conditions
?Avoid secondary insults

Anesthetic technique

? IV or volatile anaesthetic agents?
? There is little evidence to support the use of

one over the other

? All volatile agents reduce CMRO2, produce

cerebral vasodilatation- resulting in increased

CBF and ICP.

? However, at concentrations up to 1 MAC these

effects are minimal

? Sevoflurane appears to have the best profile.
? N2O is best avoided
? I.V. agents reduce CMRO2, CBF, and ICP.
? Neuromuscular drugs are recommended to

prevent coughing or straining

Ventilation

? Ventilation should be adjusted to ensure adequate

oxygenation (PaO2 > 60 mmHg) and normocarbia

(PaCO2 35-45 mmHg).

? Monitoring arterial PaCO2 is recommended
? Hypercarbia (PaCO2 > 45 mmHg) to be avoided
? Hyperventilation should be used judiciously for

short-term control of ICP

? Excessive and prolonged hyperventilation may

cause cerebral vasoconstriction leading to

ischemia
Monitoring

? Multimodal monitoring
? American Society of Anesthesiology (ASA)

monitors

? Arterial catheterization is recommended for

continuous BP monitoring, ABG and glucose

monitoring in patients who require surgical

intervention

? ICP monitoring is recommended in all

salvageable patients with a severe TBI (GCS <

9) and an abnormal CT scan

? Jugular venous oximetry is often useful for

assessment of adequacy of global cerebral
oxygenation

? Brain tissue oxygen monitors have the

advantage of identifying focal areas of
ischemia which may not be picked up by
jugular venous oximetry.

? Near Infrared Spectroscopy (NIRS) offers the

capacity to conveniently and non-invasively
monitor cerebral oxygen in the intensive care
unit.
? Transcranial Doppler (TCD) ultrasonography

is a non-invasive, nonradioactive, bedside
monitor, which can provide useful
instantaneous cerebrovascular information
including changes in cerebral blood flow
velocity, cerebral vasospasm and
autoregulation

Intravenous Fluids, Blood Pressure

Management and Vasopressor Use

? BP management, including choice of fluids and

vasopressors, is of paramount importance

? BTF guidelines for the management of TBI recommend

avoiding hypotension (SBP < 90 mmHg) and

maintaining CPP between 50 and 70mmHg.

? Perioperative hypotension should be treated promptly
? Hypertonic saline may be beneficial resuscitation fluid

for TBI patients

? Current evidence does not support preference of one

vasopressor over the other to support cerebral perfusion

and the choice may have to be individualized to patient

characteristics
Coagulopathy

? Coagulation disorders may be present in

approximately one-third TBI patients and is
associated with an increased mortality and
poor outcome

? Brain injury leads to the release of tissue factor.
? Patients with GCS 8, associated cerebral

edema, SAH and midline shift are likely to

have coagulopathy

Hyperosmolar therapy

? Mannitol is commonly used for hyperosmolar

therapy

? The recommended dose of mannitol is 0.25-1

g/kg body weight

? In patients with severe TBI and elevated ICP

refractory to mannitol treatment, 7.5%
hypertonic saline administered as second tier
therapy
Glycemic Control

? Hyperglycemia after TBI is associated with

increased morbidity and mortality

? Hyperglycemia can cause secondary brain

injury

? Hypoglycemeia is equally deleterious to brain
? Given the current evidence for glucose control

for TBI in perioperative period, a target
glucose range of 80-180 mg/dl is reasonable

Therapeutic Hypothermia and Steroids

? Hypothermia reduces cerebral metabolism during

stress, reduces excitatory neurotransmitters
release, attenuates BBB permeability

? Yet, clinical evidence in terms of mortality and

functional outcomes is still inconclusive.

? Accordingly, the BTF/AANS guidelines task

force has issued a Level III recommendation for
optional and cautious use of hypothermia for
adults with TBI