Management of Traumatic Brain Injury in ICU

Question 1

What is acquired brain injury (ABI)?

Answer 1

Any brain damage that occurs after birth

• Accident or trauma (TBI)
• Stroke
• Brain infection
• Alcohol/drugs
• Disease processes (e.g. Parkinson’s)

Question 2

What is traumatic brain injury (TBI)?

Answer 2

• Subset of ABI
• Involves injury to brain causes by external force (e.g. blow to the head)
• Causes rapid movement of the brain inside the skill

Question 3

What are the primary causes of TBI in Australia?

Answer 3

• Falls
• Transportation
• Assault
• Sport (e.g. football)

Question 4

What are the 5 different times of head injury?

Answer 4

• Intracerebral hematoma/contusion
• Subarachnoid haemorrhage
• Subdural haemorrhage
• Epidural haemorrhage
• Difffuse axonal injury

Question 5

What are the characteristics of intracerebral hematoma/contusion?

Answer 5

• Location: Brain
• CT findings: Multiple microhaemorrhages
• Injury: Microhaemorrhages

Question 6

What are the characteristics of subarachnoid haemorrhage?

Answer 6

• Location: Subarachnoid space
• CT findings: Blood in sulci & fissures
• Injury: Tear of subarachnoid vessels

Question 7

What are the characteristics of subdural haemorrhage?

Answer 7

• Location: Subdural space
• CT findings: Crescent (sickle shaped)
• Injury: Tear of bridging veins

Question 8

What are the characteristics of epidural haemorrhage?

Answer 8

• Location: Epidural space
• CT findings: Biconvex (football shaped)
• Injury: Tear of meningeal arteries

Question 9

What are the characteristics of diffuse axonal injury?

Answer 9

• Location: Brain
• CT findings: No abnormalities
• Injury: Shearing of white matter tracts

Question 10

What happens without adequate cerebral perfusion?

Answer 10

Brain cells die (secondary brain injury)

Brain death = death

Question 11

How is cerebral perfusion pressure (CPP) calculated?

Answer 11

CPP = MAP - ICP
Normal = <70mmHg
Critical = <55mmHg

Question 12

What are the strategies for managing TBI?

Answer 12

• Reduce ICP
• Improve CPP
• Maximise brain tissue oxygenation (mechanical ventilation, maintain respiratory function)
• Reduce brain’s metabolic demand

Question 13

How can ICP be reduced?

Answer 13

• Posture (bed tilt)
• Mechanical ventilation
• Drainage of CSF (EVD)
• Sedation, paralysis & analgesis
• Hypertonic saline, mannitol
• Barbiturate coma
• Craniectomy (cutting out piece of skull)

Question 14

How can CPP be improved?

Answer 14

• Fluid management

- Vasopressor support

Question 15

How can the brain’s metabolic demands be reduced?

Answer 15

• Sedation +/- paralysis (medically induced coma)

- Cooling (limited evidence)

Question 16

What evidence is there for bi-frontal decompressive craniectomy in TBI?

Answer 16

• Multicentre RCT
• Lower ICPs in ICU
• Fewer interventions for ICP
• Fewer days in ICU
• But worse outcomes at 6 months

Question 17

What evidence is there for prophylactic chest physio for ventilated patients with a TBI?

Answer 17

Pateman et al 2009

• Prospective RCT of ABI patients with GCS <9
• Treatments every 24 hours vs no chest physio
• 33 developed VAP
• No differences between groups

Question 18

What is the connection between hyperinflation & ICPs?

Answer 18

• Hyperinflation blows off CO2 (hyperventilation)
• In blood vessels, CO2 acts as a vasodilator
• Low CO2 levels = relative vasoconstriction
• Vasoconstriction in the brain = lower ICP

Question 19

What are some tips for suction with unstable ICPs?

Answer 19

• Minimise number of passes (1 long better than 10 short passes)
• Ensure pre-oxygenation to avoid hypoxia
• Cluster care to minimise spikes in ICP

Question 20

How can contracture be prevented in TBI?

Answer 20

• Maintain oppositional ROM in hands (rolled up towels in hands, resting splints)
• Maintain calf length (resting splints at plantar grade, serial casting)
• Maintain shoulder ROM as able (hand behind head position, abduction on table pillows if SOOB)

Question 21

What evidence is there for passive ROM exercise to prevent contracture?

Answer 21

Cochrane review Dec 2013

• No evidence that PROM exercises prevent contracture
• Previous evidence suggests prolonged stretch for changes in muscle length

Question 22

What evidence is there for the use of tilt tables in ICU?

Answer 22

Chang et al 2004

• Survey of physios in Australian public ICUs
• 67% use tilt tables to facilitate early rehab

Question 23

What did Paulus et al 2012 find regarding MHI in ICU?

Answer 23

• Systematic review of adults intubated & mechanically ventilated
• Failed to show benefits of MHI in intubated & mechanically ventilated patients
• Associated with short-term side-effects

Question 24

What did Berney et al 2002 find regarding positioning & MHI in ICU?

Answer 24

• Prospective, randomised, crossover study
• Patients intubated & ventilated
• Addition of head down tilt to physio (including MHI) increases sputum production & improves PEF

Question 25

What did Berney et al 2004 find when comparing MHI & VHI?

Answer 25

• Randomised double crossover study
• Patients intubated & ventilated
• MHI followed by VHI 2 hours later, then reverse the next day
• Both methods improve static pulmonary compliance & clear similar volumes of secretions