Brain Flashcards
what are the principles of management in increasesed ICP?
reverse ICP to normal level
maintain cerebral perfusion pressures (70-80 mmHg)
monitoring both BP and ICP to calculate CPP (CPP = MAP - ICP)
what is the brief history that should be taken for any head injury?
when? how? where?
Did you fit? Are you epileptic? Lucid interval?
alcohol or drugs?
what is the doses of BZDs for termination of seizures?
IV lorazepam 0.1 mg/kg as a slow bolus, repeat after 15 mins
iv diazepam / buccal midazolam
midazolam - 10 mg if >10 years old, 7.5 mg if 5-10 years old, 5 mg if <5 years old
squirt half dose into the mouth between lower gum and cheek
what are the common causes for seizures?
epilepsy (unknown, known and undertreated)
hypoglycaemia
pregnancy - pre-eclampsia
alcohol and drugs (withdrawal or intoxication)
CNS space-occupying lesion or infection (encephalitis)
hypertensinve encephalopathy (& 2ary causes)
what is the definition of status epilepticus?
seizures lasting >30 minutes, or multiple seizure activity lasting >30 minutes without a lucid interval between
what is the diagnostic investigation for a cerebral abscess?
contrast-enhanced CT head/MR head
‘ring-enhancing’ lesion
foundation management of cerebral abscess
escalate to neurosurgery and ID
full examination looking for sources of infection - teeth, ears, nose, skull #, endocarditis
check the patient for immunosuppression/immunocompromise and seek advice for stopping these medication. consider how this will affect antibiotic treatment.
what diseases also present with symptoms similar to meningitis?
fever, altered consciousness, shock
encephalitis, septicaemia
malaria, dengue
subarachnoid bleed
what is the rule for deciding on LP in a case of suspected meningitis?
if LP can be done in the first hour and there are no signs of shock, peitichial rash or raised ICP then do it
otherwise, give antibiotics immediately
what bugs cause meningitis?
- neisseria meningitidis*
- streptococcus pneumoniae*
- haemophilus influenzae*
- listeria monocytogenes*
HSV, VZV, CMV, enteroviruses
toxoplasma gondii, mycobacterium tuberculosis
what are the principle points of management for meningitis?
ICP vs diagnostic LP - check with a CT head, fundoscopy etc for raised ICP before trying to do an LP
antibiotics - minutes save lives, get them on board early
steroids are helpful if there are signs of meningism
contact tracing - ask a senior for help about contacting uni dorms or schools. more serious for people who have kissed the patient’s mouth
managemnet of sepsis
swabs - throat swabs for both bacteria and viruses
what GCS do people need to have ICU involvement ?
GCS <= 8
what are the signs of basal skull fracture?
what specific treatment should be given in this case?
battle sign, panda eyes
haemotympanum
CSF leak from nose or ear
tetanus immunoglobulin 250 U initially
what are the early and late complications of head trauma?
early - extradural/subdural haemorrhage, seizures
late - chronic subdural haemorrhage, seizures, diabetes insipidus, SIADH, parkinsonism, dementia
what are the indications for emergency (<1 hour) CT head in any head injury?
- GCS - less than 13 on initial assessment, less than 15 2 hours following injury
- focal neurology
- fractures - signs of basal skull #, depressed or open skull #
- post-traumatic seizure
- >1 episode of vomiting
what is the dose for suspected viral encephalitis?
aim to start aciclovir iv 10 mg/kg/8 hours over 1 hour for 14 days within 30 minutes of presentation, empirical treatment for HSV-2
specific treatments also exist for CMV and toxoplasmosis if they are suspected
- CMV = ganciclovir and foscarnet
- toxoplasmosis = pyrimethamine, sulfadiazine, calcium folinate
what are the considerations for phenytoin when used for termination of seizures?
should be done under serior guidance/ITU monitoring available
phenytoin = slows heart and drops BP.
do not give in the setting of heart block or bradycardia
requires BP and cardiac monitoring
don’t mix phenytoin and diazepam in the same IV cannula
what are the antibiotics empirically for meningitis?
ceftriaxone 2g/12 hours iv
add amoxicillin 2 g/4 hours if patient in at the extremes of age or immunocompromised
if suspect viral meningitis or encephalitis, treat with aciclovir 10mg/kg q8 hours
indications to perform an urgent (<8 hours) CT head in any head injury?
ACHA
- age > 65 years old
- coagulopathy
- high-impact injury
- retrograde amnesia >30 mins before accident
what is the normal values of CSF fluid?
<5 lymphocytes/mm^3, no neutrophils
protein 0.15-0.45 g/L
glucose 2.8-4.2 mmol/L
what are the investigations for encephalitis?
what bug?
blood cultures and serum for viral PCR
LP
throat swab for bactiera and viruses
toxoplasma IgM titre, thick and thin blood film
images
contrast-enhanced CT head
extra - EEG with diffuse abnormalities supports an urgent diagnosis
what is the steroid that you could give in meningitis? what is the indication?
meningism - give steroids
dexamethasone 8.3 mg every 6 hours for 4 days
what are the principles of management of head trauma?
ABC and resus, treat any shock accordingly
immobilize the C spine if # cannot be excluded
achieve haemostasis
monitor for and treat any seizure activity
assess neurology - GCS until 15, focal neurology, pupils, amnesia (antero-/retro-)
evaluate skull for fractures
evaluate for emergency/urgent CT head
polytrauma radiological survery (CT abdo, chest, neck and pelvis)
escalation to ITU/anaesthetics for airway and neurosurgery for fractures/ICP
what investigations should be ordered for continuous seizure activity?
what is done before/after the initiation of treatment?
- *before treatment** - capilary blood glucose
- *after treatment** - everything else
standard: serum glucose, ABG, U&E, Ca2+, FBC. ECG.
monitoring: SpO2 and cardiac monitor
drugs: consider anticonvulsant levels if known epileptic to monitor for compliance.
toxicology screen for recriational drugs.
extra: LP, culture blood and urine, EEG, CT head, CO levels.
some specifics of managing ICP that can be done by FY1
elevate head of bed to 30-40 deg
therapeutic hyperventilation aim PaCO2 3.5-4 kPa.
osmotic diuresis using mannitol, aiming for serum 300 Osm
fluid restriction to <1.5 L per day
escalation to ITU. neurosurgery for focal causes
