Disorders of Conciousness Flashcards
What is the difference between arousal and awareness?
Arousal is the degree of wakefulness
Awareness/alertness is the degree of responsiveness to external stimuli
Define a confused level of consciousness
One that is disoriented in time/place/person
Define a delirious level of conciousness
Disoriented (in space/time/person) + restless/agitated + sometimes hallucinating
What is Obtunded?
Obtunded = reduced alertness + slow responses (awareness)
Present (correct formatting) the GCS score of someone who Obeys commands, is oriented in space/time/person when asked but only opens their eyes to pain?
GCS: 2/4, 5/5, 6/6
Present (correct formatting) the GCS score of someone who flexes their arm to pain, is cussing at you, and opens eyes spontaneously
4/4, 3/5, 3/6
Present (correct formatting) the GCS score of someone who extends their arm to pain, is confused, and opens eyes only to your voice
3/4, 4/5, 2/6
Present (correct formatting) the GCS score of someone who elicits no response to pain and is only mumbling
1/4, 2/5, 1/6
Present (correct formatting) the GCS score of someone who localizes to pain, is not making any sounds and eyes closed unless their is pain.
2/4, 1/5, 5/6
Present (correct formatting) the GCS score of someone who withdraws their arms to pain, is rambling about their sad days.
4/4, 4/5, 4/6
Give 5 intracranial and 5 extracranial causes of reduced conciousness
Intracranial = TBI, stroke, space-occupying lesion, subarachnoid hemorrhage, hematoma, infection (meningitis, encephalitis), Seizures, non-convulsive status epilepticus, Wenicke’s encephalopathy
Extracranial = Cardiac (shock), Resp (Any cause of T1 or T2RF), Renal failure (hypernatremia), endocrine (glucose/thyroid), pH disturbances, alcohol withdrawal, sedatives, poisons and toxins.
Quick history on loss of conciousness
First collateral history going through the course of LOC (before, during, after) including
focal signs before,
seizure activity,
head trauma,
when last seen well
Drug/medication hx with potential for OD/poisoning?
Past psych hx
What are the clinical features of a patient presenting with brain injury?
Reduced GCS: Altered consciousness
Raised ICP: Headache, vomiting, hypertension, bradycardia
Seizures
What part of the ECG is particularly important when suspected of OD?
QT length
When ordering a toxic screen what should you make sure is included other than the typical drugs?
Paracetamol and salicylates as they are one of the most common ODs
What is the first line imaging for all LOC?
Neuroimaging - non-contrast CT
What investigations would you order
If having trouble, its very easy if you ensure youre checking for all your causes
Bedside: Glucose (seizure), urinalysis (UTI), ECG (QRS and QT length imp in OD), ECG (QRS and QT length)
Lab: Bloods (FBC, UandE - renal failure, coag screen -TBI, LFTs (hepatic encephalopathy), Toxic screen (INCLUDE PARACETAMOL and SALICYLATES)
ABG
Blood/urine cultures and viral swabs (sepsis, meningitis and encephalitis) - LP if high suspicion
Neuroimaging: NON-CONTRAST CT (mass effect, hematoma, hemorrhage stroke, TBI)
Endocrine (TFTs)
The general management of LOC is via ABCDE and treatment of the underlying cause. Treat the following underlying causes appropriately with correct dosages and methods of administration.
Hypoglycemia
Hypoglycemia with alcohol abuse history
Infection
Opioid toxicity
Increased ICP (pharmacological dw the rest will come)
Hypoglycemia: IV 50 ml 50% glucose followed by IV 100mg Thiamine
Hypoglycemia with alcohol abuse history: IV 100mg Thiamine followed by IV 50ml 50% glucose
Infection: Antibiotics (Ceftriaxone)
Opioid toxicity: Naloxone
Increased ICP: Mannitol/Hypertonic saline
Most seizures resolve spontaneously within 2 minutes. In an emergency requiring ABCDE approach. How would you manage aside from the typical ABCDE approach.
1) IV thiamine 100mg
2) IV 50% glucose 50ml
3) If longer than 2 minutes: IV Lorazepam (0.1mg/kg max 4mg) can be repeated once. If no IV access Buccal Midazolam (10 mg if >40kg) or Rectal Diazepam (0.2-0.5mg/kg max=20mg) as second line
4) If longer than 5 minutes => ongoing status => Alert anesthetics and ICU where they will administer IV phenytoin/phenobarbitone
5) Refractory Status, nothing is working => General anesthesia (Propofol)
When is a Bag-mask indicated over a non-rebreather mask?
If RR<8
In an emergency situation, when is intubation indicated?
GCS 8 or lower
Many drugs and poisons have a high risk of dysrhythmias. How would you treat it in an acute setting?
4As: Adenosine, adrenaline, amiodarone, and atropine
What is the relation of cerebral blood flow to CO2 and PO2?
Cerebral blood flow increases when CO2 increases => Vasodilation
Cerebral blood flow decreases when PO2 increases => Vasoconstriction
In an emergency situation, it is often essential to get the substance out of the system as quickly as possible. How would you acutely increase elimination?
Gastric/gut lavage
Activated charcoal
and Hemodialysis (in this order)
In terms of poisoning/OD, it is typically difficult or impossible to know the exact substance ingested in an acute setting. In an emergency situation with the ABCDE approach, go through every step
1) Get data from first responders (pre-hospital) and put on PPE to prevent exposure to some
2) Toxidrome-oriented physical examination looking for patterns of signs consistent with groups of agents
3) ABCDE approach
A: Often difficult to keep open reliably => intubation with consideration of rapid sequence intubation (RSI) if needed
B: 100% Non-rebreather mask 15L/min and Bag mask if GCS<8
C: Treat hypotension with fluid bolus IV 500ml normal saline and Vasopressors (norepinephrine, vasopressin).
Treat Dysrhythmias with 4As: Adenosine, adrenaline, amiodarone, and atropine
D: Treat hyperglycemia with 100mg Thiamine IV and 50% 50mg Glucose IV (alcohol suspicion) + Reverse known agents as appropriate (e.g. naloxone 400mg for opioid)
E: Exposure and elimination: Correct hyperthermia with paracetamol and look for any marks, swellings, IV marks for drugs etc…
ELIMINATION: Gastric/gut lavage, Activated charcoal, and Hemodialysis (in this order)
REFERRAL TO TOXBASE
A patient presents in the emergency department with increased HR and BP, high body temp, dilated pupils, no bowl sounds and anhidrosis. What is the most likely group of drugs? Give 2 examples
Anticholinergic: Atropine, antihistamines
A patient presents to the emergency department with pinpoint pupils, normal bowel sounds and diaphoresis. What is the most likely group of drugs? Give 2 examples
Cholinergic: Pilocarpine, mushrooms
A patient presents to the emergency department with low HR, BP, RR, and body temp. They have pinpoint pupils , no/reduced bowel sounds, and anhidrosis. What is the most likely group of drugs? Give 2 examples
Opioid: Tramadol, fentanyl, oxycodone, codeine, morphine…
A patient presents to the emergency department with reduced HR, BP, RR, and body temp. They have reduced bowel sounds and anhidrosis. What is the most likely group of drugs? Give 2 examples
Can be opioid or Sedative/hypnotic. We would need to check the pupils. If they are constricted then its probably opioid: Tramadol, fentanyl, oxycodone, codeine, morphine…
If there is no change and the pupils are normal then it is probably a Sedative Hypnotic: Anti-anxiety medications, anti-epileptics, benzos, parasympathetics
A patient presents to the emergency department with increased HR and BP, high body temp, and dilated pupils. A colleague suggests an anti-cholinergic overdose such as atropine. You disagree. What is your alternative and what additional characteristics differentiate it from an anti-cholinergic overdose? Give 2 examples
Sympathomimetic: Cacaine, ritalin, LSD, Caffeine, MDMA, ecstasy
Here, there would be increased HR (normal in anti-cholinergic), presence of bowel sounds (constipation in anticholinergic), and diaphoresis (anhidrosis in anticholinergic obviosiously)
What is the difference between a primary and secondary injury in TBI (traumatic brain injury)
Primary is the direct initial insult. Secondary injury are the factors that exacerbate or worsen the primary injury.
How would you grade the severity of a TBI?
GCS scoring.
Mild 13-15
Moderate 9-12
Severe <9
What is the normal range of ICP and at what ICP would you treat it in a TBI?
Normal = 7-15mmHg
Treat if >22mmHg
At what GCS score do we intubate in TBI?
At what GCS score do you intubate anyways?
TBI <9 = severe TBI which is the same as normal which is 8 or less
Intubation also occurs in TBI if SPO2<90
What is Cushing’s triad in trauma?
What is its significance?
Bradycardia, hypertension (widened pulse pressure), and irregular respirations
Classic sign of intracranial hypertension
How is ICP monitored in TBI?
What are the indications to monitor ICP in TBI?
What is the cutoff to begin treatment?
What are all the lines of management?
Monitored via a probe most commonly inserted intraventricularly. Others include intraparenchymal, subarachnoid, and epidural
Indications for monitoring: Either
1) GCS <8 + CT evidence of Mass effect
2) Normal CT and 2 of: age>40, systolic <90, Motor posturing
Treatment for increased ICP in TBI is indicated when ICP >22mmHg
1) Drainage of CSF
2) Sedation (lowers metabolic demands)
3) Hyperosmolar therapy (mannitol - osmotic diuretic, hypertonic saline)
4) Surgical measures e.g. Craniotomy, drainage of hematoma, Burrholes, ventricular drain, Decompressive craniectomy (bad quality of life in the long-term)
What is the most common location to monitor ICP in TBI? Why is it the preferred one?
Intraventricular is the most common as it also allows for drainage of CSF as is the first line management.
Others include intraparenchymal, subarachnoid, and epidural
What is Cerebral perfusion pressure?
What is the normal amount?
What would happen if it is reduced?
CPP = MAP (ABG) - ICP (Probe)
Normal = 60-70 mmHg
Reduced = secondary ischemia
How would you determine bleeding risk and coagulopathy? What are the normal values. What would be considered a risk?
Coagulopathy screen/INR
Normal is 1
High >1.5
Give the likely diagnosis/finding of Loss of Consciousness + the following symptoms:
tachycardia + hypotension:
tachycardia + Hypertension + Hyperthermia:
Bradycardia + Hypertension + Papilloedema on fundoscopy:
Bradycardia + Widened pulse pressure + irregular respirations:
tachycardia + hypotension: Shock (any type)
tachycardia + Hypertension + Hyperthermia: Anticholinergic toxicity
Bradycardia + Hypertension + Papilloedema on fundoscopy: Raised ICP
Bradycardia + Widened pulse pressure + irregular respirations: Cushing’s triad/Intra cerebral hypertension
Give 2 diagnoses for each
Constricted pupils
Dilated pupils
unequal
Constricted pupils: Opioid or cholinergic
Dilated pupils: Anticholinergic or sympathomimetic
unequal: Herniation or Stroke
What is ecchymoses?
Bruising (evidence of mild internal bleeding)
Finding many areas of petechiae and ecchymoses would make you suspicious of
Bleeding disorder or coagulopathy
Jaundice and LOC whatre we concerned about?
Hepatic encephalopathy
Neck stiffness in a patient in the ED with no fever. Whatre we concerned about?
Subarachnoid hemorrhage
2nd: meningitis
When should C-spine stabilisation be implemented?
When there is any suspicion of trauma to the head
A patient presents to the ED with tachypnea, signs of increased work of breathing and is vomiting. Their SpO2 reading is 98%. What is your most likely diagnosis?
Carbon monoxide poisoning. It can trick the SpO2 monitor into giving elevated readings.
What are the conditions that preclude the diagnosis of braindeath? (3)
If these conditions are met, there will be no preclusion to the diagnosis of brain death:
1) Patient is observed to have fixed, dilated pupils and absent cranial nerve responses for 4 hours
2) Documented underlying neurological diagnosis which caused the severe neurological injury and accompanying loss of brain stem reflexes
3) Exclude reversible causes of coma:
a) No drugs/toxins/sedatives/muscle relaxants (must say all)
b) Normothermic and normotension (SBP>90 or MAP>60)
c) Absence of severe electrolyte, metabolic, or endocrine disturbances
d) Must be able to perform brain reflex testing (one eye and one ear) and Apnea Test (not if in ARF or cervical spine injury)
You are asked to conduct brain reflex testing to confirm brain death. The preconditions have been met. List all 8 tests and what you would do after
SKIP
1) Absent Motor Responses
2) No pupillary response to light
3) Corneal reflex
4) Oculovestibular reflex
5) Oculocephalic Reflex (if #4 unable to be performed)
6) Pharyngeal reflex
7) Laryngeal reflex
8) Apnea test
I will need to complete this test on 2 separate occasions to declare the patient dead
Only at this stage is the decision of organ donation discussed with the family
How would you assess absent motor responses for brain death
SKIP
Pressure on supraorbital notch (trigeminal nerve distribution). Should elicit extreme pain but if brain dead, no response
How would you assess pupillary response to light for brain death?
SKIP
Dim room. Pupils should be >4mm in diameter. Then shine light and assess reflex (brisk constriction). If brain dead, not change in pupil size
How would you assess corneal reflex
SKIP
Touch cotton wool on cornea to elicit blink reflex. No blinking if brain dead
How would you assess the oculovestibular reflex?
SKIP
Before testing, I must ensure that there is no damage or obstruction to the tympanic membrane or canal as well as no base of skull fracture. Otherwise I will conduct the Oculocephalic Reflex (must include)
For the test, I will irrigate the canal with 50ml of ice cold water. There should be slow movement of the eyes towards the ear. Any movement of the eye will exclude brain death
How would you assess the Oculocephalic Reflex?
SKIP
This test would be skipped if the oculovestibular reflex was conducted. To perform this test, you must also ensure that there is no cervical spine injury (must include)
For the test, Turn the head to one side. This should elicit the eyes to turn in the direction opposite to the head. In brain death, there is no movement of the eyes=> eyes will “move” in the direction of the head.
How would you assess the Pharyngeal reflex?
SKIP
Using a tongue depressor, stimulate each side of the oropharynx looking for any palatal or pharyngeal movement. No movement if brain death
How would you assess the Laryngeal reflex?
SKIP
A suction catheter is introduced into the ET tube to stimulate the Carina to elicit the cough reflex. No cough in brain death
Where is the carina located
It is located at the bifurcation of the bronchi
How would you conduct the Apnea test?
SKIP
This must be the last test performed.
1) Pre-oxygenate the patient to ensure normal levels of PaCO2 or if not possible, establish the patient’s baseline
2) Disconnect the patient and attach to C-circuit for provision of oxygen. This C-circuit has a reservoir bag which is used to easily monitor any resp effort.
3) ABGs are checked at 5 minute intervals until pH <7.3 and PaCO2>8kPA (or2.7kPa above baseline)
4) If despite hypercapnia/hypercarbia and acidemia, there is no attempt at spontaneous ventilation, this is consistent with brain death
What are the absolute contraindications to organ donation? Give 6
Age 85 or over
Primary intracerebral lymphoma and any secondary intracerebral tumour
Any active cancer with evidence of spread outside affected organ within 3 years of donation
Melanoma except if completely excised when in stage 1
Any active hematological malignancies (myeloma, leukemia, lymphoma)
Active and untreated Tb
West Nile Virus
HIV disease (not infection)
History of Ebolavirus infection
Suspected case or familial case of Human TSE (transmissible spongiform encephalopathy)
Neurodegenerative diseases a/w infectious agents
What is the warm ischemia time? When do you start timing it?
How would you describe the warm ischemia time in brain death organ recovery?
The warm ischemia time is the amount of time that an organ remains at body temp after its blood supply has stopped or been reduced. Different organs can withstand different warm ischemia times.
Timing begins once the BP falls <50mmHg systolic
In brain death organ recovery, once support is ceased, the heart stops at the same time and hence the organs are cooled => warm ischemia time is very minimal. In cardiac death it is longer as activity hasn’t ceased completely
Who makes the decision to withdraw support?
Primary physician/surgeon + intensivist
with second opinion from neurologist and second intensivist
What are the preconditions that must be met for donation after cardiac death? (2)
1) Must be a ventilated patient from whom treatment is withdrawn
2) Death is likely to occur in less than 60-90 minutes post-withdrawal of tx. The estimation is based on whether the patient breathes spontaneously after withdrawal
When do you decide to reinstate life-saving measures after decision to withdraw treatment has executed?
If the patient hasnt died within 90 minutes
After withdrawing treatment, when do you pronounce the patient dead, and when do you begin the organ donation process?
After 5 minutes of continuous asystole on the ECG, the patient is pronounced dead
An additional 5 minutes is waited to ensure no spontaneous return of circulation. Organ donation is then initiated
A previously fit and healthy 18 year old male is in a motorbike accident on presentation he is eye opening to verbal stimulus, making incomprehensible sounds confused, withdrawing from painful stimuli.
You are the intern on call for ED and you are asked to review this patient by nursing staff prior to his CT scan as he is agitated, and the nurse wonders if he will need sedation to lie still.
What is most appropriate action :
A - Accompany the patient to the CT scanner, bringing IV sedation with you in case it is needed
B - Call the ICU registrar to establish secure airway- intubate & ventilate
C - Call radiology to urgently expedite his scan
D - Call your registrar to give the patient the benzodiazepine Midazolam 5mg prior to the scan
E - Give analgesia – Oxynorm 5mg
D - Call for senior help and give benzo to sedate the patient
