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Flashcards in CBD 3: Coma Deck (17)
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1

A young male patient is brought in by the ambulance service. He had been found in the stairwell of a block of flats in an unresponsive state. There is little more information about him as there is no one with him. His pockets are empty, so it is impossible to even determine his name or age from documents such as a driving licence, which he might have been carrying with him.
Your initial assessment combined with the nursing observations reveals the following:
A — Airway clear and maintained spontaneously
B — Shallow breaths, RR 12, SpO2 100% on 15L. Chest clear.
C — HR 92 regular. BP 120/60. CRT < 2 secs
D — Responsive to pain, but not to speech. PEARL
E — Temp 36.2, no rashes, abdo and calves SNT

CBD: case 3

2

What biochemical test would you want to know the result of in the first few minutes after the arrival of any unconscious or semi-conscious patient? Why is this so important?

Blood glucose

Prolonged hypo = brain damage

3

Patient is opening his eyes to painful stimuli only, pulling his arm away when painful stimuli is applied to his hand, and makes a groaning noise at the same time.

a) What does this make his GCS?
b) What may you need to do?
c) Flaws of using GCS in some situations
d) What methods are used for applying painful stimuli?

Motor - 4 (withdraws from pain)
Verbal - 2 (incomprehensible sounds)
Eyes - 2 (opens to pain)

Total GCS = 8

b) - Try simple manoeuvres and adjuncts
- Call 2222 for airway management if not responding

c) Uncomplicated stroke - normal conscious level, but reduced verbal/motor response so reduced GCS

d) Mastoid pressure, earlobe pressure, trapezius squeeze, supraorbital pressure

4

Coma.
a) Define
b) Less severe states of impaired consciousness

a) A state of profound unconsciousness and unresponsiveness caused by disease, injury, or poison.

b) - Stupor/obtundation - can be aroused (eg. by pain)
- Drowsiness
- Delirium
- Vegetative/minimally-responsive states

5

Causes of coma.
- VITAMIN C DEF

Vascular.
- Massive MI or PE
- Brainstem stroke

Infective/inflammation
- Sepsis
- Anaphylaxis
- Meningoencephalitis

Trauma.
- Head injury - SDH, EDH, SAH, ICH
- Seizures - epilepsy (status)

Autoimmune.
-

Metabolic.
- Hypoxia, hypercapnia
- Hypoglycaemia
- Renal failure - uraemia
- Hepatic encephalopathy - raised ammonia
- Abnormal...Na+, Ca2+, etc.
- Hypothermia, hyperpyrexia

Iatrogenic/intoxicants
- Alcohol
- Recreational drugs - heroin, cocaine, ecstasy
- Prescription drugs - opiates, benzos, paracetamol
- Carbon monoxide poisoning

Neoplastic.
- Brain tumour - primary, secondary

Congenital
- CAH

Degenerative/deficiency
- Thiamine (alcohol)

Endocrine.
- Pituitary/adrenal failure
- Thyroid - myxoedema coma, thyroid storm

Functional (psychiatric, etc.).

6

Coma: assessment.
a) A-E

Airway.
- Is it patent?
- If not responsive to pain, likely GCS < 8 so will need airway support - intubation

Breathing.
- Hypoventilation - consider opiate overdose
- Rapid/shallow - stimulant overdose
- Deep - acidosis (eg. Kussmaul in DKA)
- Tracheal deviation, asymmetrical expansion (tension pneumothorax)
- SpO2 and RR monitoring
- Consider oxygen and ventilation

Circulation.
- HR, BP, urine output, etc.
- Fluid status

Disability.
- Glucose - hypo, DKA, HHS
- Pinpoint pupils - opiate overdose
- Fixed pupils, focal neurology - raised ICP, other

Exposure.
- Hypothermia - primary, myxoedema, sepsis
- Hyperthermia - sepsis, heat-stroke,
- Skin colour - jaundice (alcohol), cherry-red (CO)
- Rashes, bleeding, etc.

7

Coma: investigations

Bedside.
- ECG
- Capillary blood glucose
- Urine - dipstick, toxicology, pregnancy

Bloods.
- ABG - resp/metabolic acidosis/alkalosis
- FBC (infection, bleeding)
- CRP (infection, inflammation)
- Blood cultures + septic screen
- U+Es (metabolic, renal)
- LFTs (liver failure, paracetamol)
- TFTs, troponins, CK, etc.
- Paracetamol, salicylate and alcohol levels

Imaging.
- CT head
- CXR

Special tests.
- LP
- EEG

8

Your patient's respirations have become shallower whilst you have been thinking. You count the rate and it is now only 8 breaths/minute. The staff nurse points out that he has 'pinpoint pupils'.

- Diagnosis?
- Initial Rx?
- Specific Rx?
- Monitoring?

a) Opiate overdose

b) ABC (airway management, ventilation, oxygen, circulatory support)

c) IV or IM naloxone (Narcan) - dose: incremental infusions of 50-100 micrograms (not too quickly, due to short half life of naloxone - will recover too quickly, run out of ED and collapse when naloxone wears off while heroin still takes effect, then they will die.

d) - Ventilation, BP, basic obs.
- Don't seek to wake them straight away

9

What features o/e would alert you to opiate overdose?

Airway/breathing.
- Reduced RR

Circulation.
- ?

Disability.
- Pinpoint pupils

Exposure.
- Track marks
- Needles

10

Coma management.

Airway and breathing.
- Stabilise airway
- High-flow oxygen
- Hyperventilate and head up if raised ICP

Circulation.
- IV fluid challenge - 500 ml NaCl 0.9%
Other possible treatments...
- IV glucose
- IV thiamine
- IV antibiotics
- IV hydrocortisone
- IV naloxone / flumazenil
- IV mannitol

Surgical - consider for raised ICP

11

Basilar skull fracture.
a) management
b) measuring the collar
c) investigations
d) signs

a) Stabilise the C-spine: hard collar, speed collars and velcro/tape to hold head still

b) measure finger breadths from angle of jaw to clavicle

c) CT head and CT C-spine

d) Racoon eyes (periorbital ecchymosis)
Battle sign (mastoid ecchymosis)
CSF rhinorrhoea or otorrhoea
Haemotypanum
Bleeding from the ears

12

A call for urgent help comes form the nurse who is in the CT scanner with the patient. He has vomited profusely.
a) How do you clear his airway?
b) How can further aspiration be prevented?

a) Suction and log roll (recovery position, where concerns over C-spine to maintain full spinal alignment)

b) Intubation with rapid sequence induction (induction agent and neuromuscular blockade)

13

NG tube: contraindications

Basilar skull fracture (cribrifrom plate damage - tube will go into the brain) - instead pass an orogastric tubr

14

Vegetative states.
a) Persistent (PVS)
b) Minimally conscious state
c) Locked-in syndrome
d) Brainstem death

a) - Patient is awake but does not exhibit awareness of their surroundings;
- Lose higher brain function
- Retain non-cognitive brain functions and have normal or near-normal sleep-wake patterns

b) Patient is awake and has minimal awareness of their surroundings.

c) No voluntary control of movement, but full awareness. May communicate using movements of eyes or eyelids.

d) Irreversible loss of all brainstem functions; lose brainstem reflexes and cannot breathe spontaneously

15

GCS vs. AVPU scoring

Alert ~ 15
Voice ~ 12 - 14
Pain ~ 8 - 11
Unconscious < 8

16

Monroe-Kellie doctrine.
a) Explain
b) Cushing reflex
c) Equation for cerebral perfusion pressure

a) Fixed box (only escape is foramen magnum):
We can respond to increases in intracranial volume via losing CSF and venous volume to maintain a low ICP and adequate cerebral perfusion pressure

b) ICP > 30... ischaemic medullary vasomotor centre, leading to hypertension and bradycardia. Abnormal respirations indicate coning.

c) CPP = MAP – ICP

17

Management of raised ICP
a) Pre-surgical
b) Surgical (if required)

a) - Raise head up to 30 degrees
- Give oxygen (hypoxia causes raised ICP)
- Hyperventilate (hypercapnia causes raised ICP)
- IV hypertonic saline/mannitol (draw water out of brain)
- Optimise BP (fluids and vasopressors)

b) - Call neurosurgeons if GCS going down, focal neurology, etc.
- Craniotomy, etc.