Integument & eye Flashcards
Name causes of mydriasis / miosis (that are not related to brain injury)
- Mydriasis:
- Pharmacological: atropine (topical or systemic), tropicamide
- Glaucoma
- Lens luxation
- Optic neuritis
- Retinal detachment
- Chorioretinal inflammation
- Iris atrophy - Miosis:
- Pharmacological: latanoprost, pilocarpine
- Anterior uveitis
- Horner’s syndrome
- Corneal ulcer
What is the desired pressure to flush wounds
7-8 psi (can be achieved by using a 0.9 NaCl in a pressure sleeve at 300 mHg)
Recommended to use a 60 mL syringe with an 18 Ga (=pink) needle or a 35 mL syringe with a 19 Ga (=cream) needle
What is lagophtalmos
Lack of complete eyelid closure
What are signs of an infected corneal ulcer and what is the recommended treatment
Any corneal ulcer with stroma involvement is considered infected. Stromal infiltrates, corneal malacia, and reactive anterior uveitis can also be present.
Treatment:
- Broad spectrum antibiotics combining a fluoroquinolone (ciprofloxacin) + cefazolin or neomycin-polymixin-gramicidin or tobramycin -> every 15min for first hour then every 2h until signs of resolution
- Antifungal (voriconazole) if fungal infection is suspected
- Antiprotease (serum) if keratomalacia -> every 2h until signs of resolution
- Atropine for comfort (mandatory if anterior uveitis is present) IF IOP NOT ELEVATED
- Systemic NSAID if uveitis is present (topical NSAIDs to be avoided with ulcer)
What is the treatment for anterior uveitis? What is a common complication?
Treatment:
- Topical steroids if possible (otherwise topical NSAIDs but less efficient)
- Systemic steroids / NSAIDs if severe
- Atropine if IOP is low to low-normal - any elevated or high-normal IOP in the face of uveitis indicates glaucoma (in these cases atropine is contra-indicated and dorzolamide should be instituted)
What are treatments for glaucoma and their mechanism of action +/- contra-indications
- Prostaglandin analogs (Latanoprost) -> increase outflow of aqueous humor
Contra-indications: uveitis, anterior lens luxation - Carbonic anhydrase inhibitor (dorzolamide) -> decrease aqueous humor secretion
- Beta blockers (timolol) -> decrease aqueous humor production
Contra-indications: cardiac disease, asthma - IV mannitol -> osmotic “drainage” of aqueous humour
Contra-indications: uveitis (permeable blood-eye barrier), cardiac disease, dehydration
What are differentials for acute blindness
- Glaucoma
- Retinal detachment (eg. systemic hypertension)
- Retinal toxicity (eg. fluoroquinolones in cats, ivermectin in dogs)
- Uveitis
- Optic neuritis
- CNS disease
- Prolonged compression of maxillary artery in cats
- SARD (sudden acquired retinal degeneration)
What are the bacteria most commonly cultured from bite wounds
Pasteurella spp
Staphylococcus spp
Streptococcus spp
In 2 other studies says Staphylococcus, E Coli, and Enterococcus…
What is the classification of wounds
- Clean: atraumatic, surgically created under aseptic conditions
- Clean contaminated: minor break in aseptic surgical technique (eg. opened GI)
- Contaminated: Recent traumatic wound with bacterial contamination vs major break in surgical asepsis (eg. spilled GI content, all penetrating wounds)
- Dirty or infected: older wound with exudate or obvious infection –> >10^5 organisms/g of tissue
What are the phases of wound healing
- Inflammation and debridement (first 5 days after injury)
- Proliferation (starts 4 days after injury, lasts 2-3 weeks) -> epithelialization, angiogenesis, fibroplasia (granulation tissue)
- Maturation (starts 17-20 days after injury)
What are the 3 possible timings of wound closure and their indications
- Primary closure: for clean fresh wounds, contaminated wounds, or infected wounds that can be excised completely
- Delayed primary closure (2-5 days after injury): for contaminated wounds or large wounds with questionable viability (closed when viable granulation tissue is present)
- Secondary closure (5 or more days after injury): for dirty wounds or very extensive wounds with severe necrosis
(- Second intention healing: no closure)
Name some contra-indications to negative pressure wound therapy
- Coagulopathy
- Exposed vasculature, nerves, organs, fistula
- Malignancy in the wound
- Necrotic tissue with eschar
- Untreated osteomyelitis
What are some indications for antibiotic therapy for wounds
- Obvious local or systemic signs of infection
- Wound older then 6 hours
- Deep wound (involving muscle, bone, tendon)
- Wounds likely to get infected (bite wounds, penetrating wounds)
- When planning for a flap / graft
- Chronic non-healing wounds with infection confirmed by culture
- Immunocompromised patient
(Clean wounds less than 6 hours old or contaminated wounds that can be converted to clean and closed, or wounds that already have a mature healthy granulation tissue do not required antimicrobials)
What is the recommended empirical antimicrobial therapy for wounds based on severity
- Cefazolin for superficial wounds in stable patients
- Potentiated penicillins (Clavamox) for deeper or infected wounds
or ampicillin + fluoroquinolone /r aminoglycoside / 3rd gen cephalosporin for severe bite wounds
Antimicrobial therapy to be continued until granulation tissue covers the wound.
When is bacterial culture of a wound likely to be the most relevant
After a few days (2-5 days) on antibiotics if the wound is not healing or the patient’s condition is worsening
(Initial culture usually does not indicate what bacteria are going to cause an infection)
What topical antimicrobial is preferred for burn wounds
Silver sulfadiazine (but studies showed that honey is actually better)
