Emergencies Flashcards
What are the features of acute primary angle closure?
Pain - periocular, headache, abdominal Blurred vision Haloes Nausea Vomiting
What are the signs that a person with acute primary angle closure will exhibit?
Ipsilateral red eye Raised IOP (often 50-80mmHg) Corneal oedema Angle closure Fixed semi-dilated pupil Shallow anterior chamber
Why is acute primary angle closure an emergency?
It can cause optic nerve damage if not treated urgently.
What immediate treatment do we give for acute primary angle closure?
- Systemic acetazolamide 500mg IV stat
- Topical - beta blocker (timolol), steroids (prednisolone 15 every 15 for an hour, then hourly), pilocarpine (pts without own lens get phenylephrine)
What intermediate treatment do we give for acute primary angle closure?
- Continue acute regime according to guidelines
- Consider hyperosmotics e.g. mannitol
- Check IOP hourly
- Review diagnosis if no improvement
What definitive treatment do we give for acute primary angle closure?
Surgical peripheral iridotomy, usually at 11 and 2 o’clock positions for free flow of aqueous
What are the complications of acute angle closure glaucoma?
Loss of vision
Repeat of acute attack
Attack in contralateral eye
Central retinal artery/vein occlusion
Who can we offer prophylactic peripheral iridotomy to?
Those with shallow anterior chambers, to prevent acute angle closure glaucoma.
A young patient presents after a hit to the head with sudden decreased visual acuity and double vision.
What other signs and symptoms are suggestive of a carotid-cavernous fistula?
Audible bruit in carotids Pulsatile proptosis wit bruit Orbital oedema Injected chemotic (swollen) conjunctiva Increased IOP May have ophthalmoparesis (CN III/VI usually) Disc swelling Anterior segment ischaemia
How should a suspected AV fistula be investigated?
Orbital imaging (Doppler US/CT)
How should a high flow AV fistula be managed?
Closure by catheter embolisation
What is the blood flow to the retina, and why is this important wrt ophthal emergencies?
Central retinal artery (branch of ophthalmic from the internal carotid) which divides into superior and inferior, each of which divide into nasal and temporal branches.
Outer retina is supplied by ciliary artery branches from the ophthalmic artery.
CRAO can affect one or multiple branches, and there is no collateral supply as these are all end-branch arteries.
What are the most common causes for CRAO?
- Atherosclerosis
- Embolism usually from atherosclerosed/stenosed carotid artery
Other than atherosclerosis/embolism, what are the causes of CRAO?
- Inflammatory - Giant cell arteritis, SLE, granulomatosis etc.
- Thrombophilic disorders
- Infection
- Pharmacological (OCP, cocaine)
- Ocular trauma
When is the optimum treatment window for CRAO?
Within 90-100 minutes of onset
A patient presents to eye casualty with acute painless unilateral loss of vision. What is your top differential?
Central retinal artery occlusion
A patient presents to eye casualty with acute painless unilateral loss of vision. What do you expect to see on ocular examination and fundoscopy?
Relative afferent pupillary defect.
White swollen retina with cherry-red spot at the macula.
Segmentation of blood column in arteries.
A patient presents to eye casualty with acute painless unilateral loss of vision. What might you find on general examination of this patient?
Carotid bruits
Heart murmurs
AF
HTN
A patient presents to eye casualty with acute painless unilateral loss of vision. What are you differentials?
CRAO Retinal detachment (floaters/curtain) CRVO (fundoscopy) Acute glaucoma (painful) Acute optic neuritis (painful)
How is ?CRAO investiagted?
Fluorescein angiography and optical coherence tomography is diagnosis unsure.
Aim to rule out underlying causes e.g. AF, heart murmur, carotid disease.
ESR and CRP if over 60 for ?giant cell arteritis.
Bloods - coag, FBC, vasculitis screens, lipids, fasting glucose.
How should CRAO be managed?
As an emergency.
Treat giant cell arteritis is suspected (iv then oral steroids).
Urgent modification of RFs.
There is no Rx to reverse the visual loss :( Just have to try and reperfuse.
How can we try to reperfuse the eye in CRAO?
- Firm ocular massage (works only occasionally)
- Reduce IOP with anterior chamber paracentesis, acetazolamide/mannitol/beta blockers.
- Dilation of artery e.g. with sublingual isosorbide dinitrite
- Intra-arterial fibrinolysis w/ urokinase
A person present to eye casualty having been sprayed in the eye with an unidentified substance.
Which chemical burns can cause significant injury to the eye?
Acid and alkali
Deterrents e.g. tear gas/mace, pepper spray, mustard gas, chlorine, superglue
How does acid cause damage to the eye?
Reacts with protein and fat causing tissue destruction
Where can acid have come from for a chemical injury?
Car battery Bleach Vinegar Swimming pool chlorine Glass polishing
Why are alkali burns worse than acid burns generally?
Acid tends to form a barrier to itself after the initial burn, but alkalis and lipophilic cause liquefactive necrosis so they keep burning deeper into the tissues.
Where can alkali have come from for a chemical injury?
Ammonia (fertiliser, refrigerants) Potash Drain cleaner Car airbags Sparklers/flares Plaster/mortar/cement/whitewash
How does a chemical injury to the eye tend to present?
Pain, blurring of vision, photophobia, FB sensation, red eye, cloudy cornea, blephrospasm
How should chemical burns to eyes be managed?
IRRIGATION!!!!!!! 3 Is - Irrigate, Irrigate, IRRIGATE!!!!
Isotonic saline or lactate ringer solution, but water if not available.
Local anaesthetic drops may be needed to keep eye open for IRRIGATION!!!!!!!
pH test for neutralisation to pH 7.4 every 5 mins or so.
Urgent referral while irrigating!!!!!!!!!
Broad spec abx and anti-glaucoma therapy.
What are the prognostic factors for chemical injury to eyes?
pH Duration of contact Corneal involvement Limbal involvement Conjunctival involvement Associated non-chemical injury Duration and success of IRRIGATION!!!!!
How should a tear gas/mace eye injury be managed?
Blow dry cool air onto eyes to vaporise the CS gas (don;t stand downwind)
Decontamination of clothes and skin
Irrigate if additional chemicals used
How should a pepper spray eye injury be managed?
As a corneal abrasion with retained particles - irrigate and assess for particles, then treat as an abrasion.
Which is the only chemical you shouldn’t irrigate away?
Tear gas/mace
How should superglue exposure to eyes be managed?
Irrigate (amazing, who knew?)
Remove glue with cotton bud and warm water
Check for corneal abrasion
What is cicatricial conjunctivitis and why is it an emergency?
Conjunctival inflammation associated with scarring.
Bilateral and sight threatening so early treatment is essential.
What is corneal exposure and why is it an emergency?
Failure of the lids’ normal wetting mechanism leading to drying and damage to the corneal epithelium.
What are the causes of corneal exposure/exposure keratopathy?
CN VII palsy
Lid abnormalities
Orbital disease
What are the features of corneal exposure keratopathy?
Irritable eyes (may be worst in the mornings) Poor Bell's phenomenon Poor blink excursion Reduced blink rate Periocular muscle weakness Erosions
How do we manage exposure keratopathy/corneal exposure?
Ensure adequate lubrication, lid closure (surgical, botulinum, or temporary), and treat any secondary bacterial keratitis.
What is endophthalmitis?
Severe inflammation of the anterior and/or posterior chambers of the eye, usually due to bacterial or fungal infection.
When do most cases of endophthalmitis occur?
Post surgery to eye or penetrating ocular trauma
Why is endophthalmitis an emergency?
Delay in treatment can lead to vision loss.
What can endophthalmitis spread to become?
Panophthalmitis which involves all the layers of the eye
Why is orbital cellulitis an emergency?
It is potentially sight-threatening and life-threatening.
What is orbital cellulitis?
Infection of the soft tissues behind the orbital septum, originating mostly from spread of local infection. It is most commonly seen in children.
What is orbital cellulitis characterised by?
Eyelid oedema, erythema, and chemosis, with orbital signs and systemic signs e.g. fever.
What orbital signs are sometimes present in orbital cellulitis?
Proptosis, gaze restriction, blurred vision, double vision.
What is preseptal cellulitis?
An infection of the tissues anterior to the orbital septum.
Is pre-septal or orbital cellulitis more common?
Preseptal cellulitis
What are the signs of preseptal cellulitis?
Eyelid oedema, but absence of orbital signs.
Can preseptal cellulitis progress to orbital cellulitis?
Yes sometimes, this is more likely in children.
What predisposing factors are there for periocular cellulitis in children?
Preceeding URTI and sinusitis.
What is the most common causative organism for orbital cellulitis?
Streptococcus pneumoniae, Staph. aureus, Strep. pyogenes, and H. influenzae, and MRSA.
What is the orbital septum?
A membranous sheet which arises from periosteum around orbital margin which fuses to the tarsal plates centrally.
Where might an infection might have originated from to cause orbital cellulitis?
Paranasal sinuses, the face, the globe, lacrimal sac, and teeth. It can occur post-surgery or by direct inoculation of the orbit from trauma.
What time of year is orbital/preseptal cellulitis most common?
Winter because there is an increased incidence of paranasal sinus infection.
What are the red flags for orbital cellulitis in a child?
Fever, Leukocytosis resulting in fever.
What are the differentials for orbital/preseptal cellulitis?
Preseptal/orbital cellulitis, necrotising fasciitis, chalazion, allergic lid swelling, severe viral conjunctivitis
How is orbital/preseptal cellulitis be diagnosed?
Based on Hx and Examination, but Ix are used to find the root of the cause.
What Ix should be done when someone presents with orbital/preseptal cellulitis?
FBC, Blood cultures, swabs from skin breaks, throat and nasal swabs, CT sinuses and orbit and brain for orbital cellulitis. LP if cerebral or meningeal signs develop.
How should orbital cellulitis be managed?
Emergency referral to secondary care. IV abx e.g. cefotaxime and flucloxacillin with metroniadazole in pts over 10 with chronic sinonasal disease. Monitor optic nerve function. Treat for 7-10 days.
How should preseptal cellulitis be managed?
Emergency referral to secondary care. Oral co-amoxiclav if not pen-allergic
What complications can develop from prespetal cellulitis?
Progression to orbital cellulitis esp. in children. Can also cause lagophthalmos, lid abscess, and lid necrosis.
What complications can develop from orbital cellulitis?
Raised introcular pressure, central retinal artery or vein occlusion, optic neuropathy, endophthalmitis, orbital abscess, or intracranial complications (rare).
What is the prognosis like for preseptal celulitis?
Good
What is the prognosis like for orbital celulitis?
Good with early recognition and treatment, but immunosuppression and fungal cellulitis carry worse prognosis.
How can preseptal/orbital cellulitis be prevented?
Hib vaccination for H. influenzae-caused cellulitis. Optimal treatment of predisposing factors such as sinusitis.
What is optic disc swelling due to RICP?
Papilloedema.
What is papilloedema?
Optic disc swelling secondary to RICP.
What are the causes of optic disc swelling apart from papilloedema?
Central retinal artery or vein occlusion, optic neuritis, and congenital abnormalities.
What are the likely causes of unilateral optic disc swelling?
Demyelinating optic neuritis, ischaemic optic neuropathy, retinal vein occlusion, and diabetic papillopathy
What are the likely causes of bilateral optic disc swelling?
Papilloedema, toxic optic neuropathy, and malignant hypertension.
What causes are there for RICP causing papilloedema?
Tumour, trauma -> bleed, cerebral inflammation/infection, idiopathic intracranial hypertension, respiratory failure.
What symptoms should you ask about in a hx for optic nerve swelling?
Full systemic, neurological and ophthalmic hx, but specifically ask about symptoms of RICP as papilloedema is an emergency.
What are the symptoms of RICP that would suggest papilloedema as a cause of optic disc swelling?
Headaches, Nausea + vomiting, headache worse on waking, coughing, and beding, pulsatile tinnitus.
When examining a pt with optic disc swelling, what should be performed first and why?
Assess for relative afferent pupillary defect - it is a sign of unilateral optic nerve disorders such as ischaemic optic neuropathy, optic neuritis, and optic nerve compression.
What is the gold standard investigation for optic disc swelling?
MRI with gadolinium enhancement
Why does RICP cause optic disc swelling?
The optic nerve sheath is continuous with the subarachnoid space so the raised pressure is transmitted to the space surrounding the optic nerve, preventing axonal flow back along the nerve and causing swelling and protrusion at the nerves end in the globe.
If a pt has papilloedema, what must be assumed until proven otherwise?
That there is an intracranial mass.
https://patient.info/doctor/optic-disc-swelling-including-papilloedema
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