Raised ICP Flashcards
What is normal intracranial pressure in an adult?
0-10 mmHg at rest
When is treatment required for raised ICP?
when it exceeds 15-20 mmHg for >5 min
What are 7 symptoms and signs of raised intracranial pressure?
- Headache and vomiting
- Focal neurological signs
- Seizures
- Papilloedema
- Impaired level of consciousness: mild confusion to coma
- Signs of brain shift
- Cushing’s triad: bradycardia, hypertension, Cheyne-Stokes (irregular) breathing
What is the nature of headache in raised intracranial pressure?
worse in mornings, exacerbated by bending, associated with vomiting
When might there be focal neurological signs in raised ICP?
- if space-occupying lesions, and some metabolic conditions e.g. liver failure
- also false localising signs e.g. cranial nerve VI palsy
What is the false localising sign in raised ICP?
cranial nerve VI palsy (unable to abduct eye on affected side due to long intracranial course)
What are 3 things associated with seizures in raised ICP?
- Space occupying lesion
- CNS infection
- Metabolic encephalopathies
What is the only situation when papilloedema is present in raised ICP?
if there is CSF obstruction
What are 2 examples of signs of brain shift?
- Decreasing level of consciousness
- Brainstem dysfunction
When does the Cushing triad occur in raised ICP?
late signs (bradycardia, hypertension, Cheynes-Stokes breathing)
What are 8 causes of raised intracranial pressure?
- Head injury with intracranial haematoma/brain swelling/contusion
- Stroke: haemorrhage, major infarct, venous thrombosis
- Metabolic: hepatic or renal failure, DKA, hyponatraemia
- CNS infection (abscess, encephalitis, meningitis, malaria)
- CNS tumour
- Status epilepticus
- Hydrocephlus
- IIH
What are 3 types of stroke which may lead to raised ICP?
- Haemorrhagic
- Major infarct
- Venous thrombosis
What are 4 metabolic causes of raised ICP?
- Hepatic failure
- Renal failure
- DKA
- Hyponatraemia
What are 4 types of infection which may cause raised ICP?
- Abscess
- Encephalitis
- Meningitis
- Malaria
What are 2 things which can help with assessment of severity of raised ICP?
- GCS score (see image attached)
- Signs of brain shift and brainstem compromise
What are 6 aspects of the management of raised ICP?
- Stabilise patients
- Active means of reducing ICP
- Attempt to make diagnosis
- Treat factors which may exacerbate raised ICP
- Observe for signs of deteriorate, and attempt to reverse them
- Consider specific therapy
What are 7 aspects of stabilisation of the patient with raised ICP?
- Open airway by lying patient on side
- Give oxygen
- Take ABG
- Intubation and mechanical ventilation may be necessary due to respiratory compromise
- Correct hypotension
- Treat seizures
- Examine rapidly for signs of head injury
How should hypotension be corrected in raised ICP? 2 aspects
- volume expansion with colloids or infusions of inotropes (e.g. digoxin, dobutamine)
- fluid restriction to 1.5-2L a day
What monitoring must be performed when correcting hypotension with colloid or an inotrope infusion?
CVP (central venous pressure) and PAWP (peripheral capillary wedge pressure)
PAWP estimates left ventricular end-diastolic pressure
What fluid restriction should be performed if there is hypotension with raised ICP?
fluid restriction to 1.5-2L per day
What are 8 blood tests to perform when stabilising a patient with raised ICP?
- Glucose: DKA, HHS, liver failure(low)
- U+Es: potassium, hyponatraemia from SIADH, hypernatraemia from diuretic-induced dehydration
- LFTs
- Albumin
- Clotting studies
- Ammonium: to assess lvier function
- FBC
- Blood culture