Adult Head Injury

Question 1

Factors Contributing to Secondary Injury (6H’s)

Answer 1

• Hypoxia
• Hypotension
• Hypercapnia – causes cerebral vasodilation
• Intercranial haemorrhage
• Hypovolaemia
• Hypertension

Question 2

Primary and Secondary Head Injuries

Answer 2

Primary: Occurs at time of trauma – cerebral laceration, contusions, haemorrhage
Secondary: Occurs sometime after initial insult and is ongoing process of injury

Question 3

How to limit effects of secondary brain injury

Answer 3

• Oxygenation
• Good airway management
• Recognising the risk and regular monitoring
• Consistent VSS and intervention on changes
• Keep pt normotensive

Question 4

Head injury patho

Answer 4

Initial injury (or secondary injury)
↓
Inflammatory response
↓
Increased capillary permeability and vasodilation
↓
Increased cerebral oedema raises ICP
↓
↓CPP leads to sympathetic response
↓
Vasoconstriction leads to increased CPP
↓
Baroreceptors detect high BP and therefore parasympathetic system causes ↓HR
↓
ICP exceeds MAP resulting neuronal hypoxia and cell death
↓
Brain herniation and coning = increased brain stem pressure which causes loss of auto regulation
↓
Decorticate/decerebrate positioning
↓
Resp/Cardiac Arrest

Question 5

Cushing’s Triad

Answer 5

• HTN – caused by vasoconstriction secondary to sympathetic response to bradycardia
• Bradycardia – caused by pressure on the Vagus nerve
• Irregular respirations – caused by Cheyne stokes

Question 6

Fluid Administration with head injury

Answer 6

• Need to overcome raised ICP by maintaining CCP. Need to aim for SBP of >120mmHg
• CPP = MAP – ICP
• If ICP is rising we need to raise MAP in order to achieve CPP
  o Need to be cautious of HTN which can increase risk of bleed

Question 7

5 HEDS

Answer 7

• LOC >5 mins
• Haematoma/bruising/lac to head
• Emesis more than once
• Anticoagulants
• Neurological deficit
• Seizure activity

Question 8

S+S of rising ICP

Answer 8

• Dyspnoea
• Disorientation
• Acute confusion
• Headache
• Irregular pupils
• Slurred speech
• Seizures

Question 9

DS4 mgx

Answer 9

R+R
Pos - Supine
MICA C1
Collar