Sinus Disease & Epistaxis Flashcards
Which muscles dilate the nares at exercise in horses?
Nasolabialis muscles (facial nerve VII)
Causes of primary sinusitis?
- Bacterial – NB consider S equi var equi
- Fungal (Aspergillus)
Causes of secondary sinusitis?
Usually secondary to dental disease
Which teeth are associated with the sinuses in the horse?
- PM 4 and M1(part) are usually located in rostral maxillary sinus
- M1, M2 and M3 are usually located in caudal maxillary sinus
What signs would you expect to see with dental disease in the first and second cheek teeth?
- PM2 and 3 are not usually associated with paranasal sinuses (1st and 2nd cheek tooth)
- So if we have dental disease in these teeth
- The pus building at the apices of these teeth will cause facial distortion and enlargement/facial swelling as the primary finding
What diagnostics can be used for sinus disease?
- History (purulent (odorous) nasal discharge (unilateral))
- Physical examination
- Percussion over sinuses to detect fluid
- Nasal endoscopy
- Sinoscopy
- Radiography
- Advanced imaging, esp CT
Which sinuses are easiest to make trephine holes into for sinoscopy?
The frontal sinus or caudal maxillary sinuses
How do paranasal sinus cysts tend to present?
- Usually in young animals
- Expansive fluid filled lesions
- Can cause facial distortion if they get very large
How are paranasal sinus cysts generally diagnosed?
- Radiography - soft tissue opacity throughout sinuses +/- gas / fluid line (but can be obscured by the secondary disease, e.g. secondary sinusitis)
- Often get secondary sinusitis as normal drainage is obscured and so fluid builds up
Treatment and prognosis of paranasal sinus cysts?
- Surgical removal via a frontonasal flap
- Post-operative care as for sinusitis (promote drainage and antibiotics)
- Good prognosis - recurrence rare if you remove all of the cysts
How does primary bacterial sinusitis tend to develop?
- Usually younger horses
- Opportunistic bacteria, often Strep. sp.
- Sequel to URT infection, related to poor drainage
Clinical signs of primary bacterial sinusitis?
- Purulent unilateral (usually) nasal discharge, not foul smelling
- Lymph node enlargement (sometimes)
Diagnosis of primary bacterial sinusitis?
- Radiography - gas/fluid lines
- Pretty much in horizontal straight line
- Need to determine whether it is a primary disease or a secondary disease
Treatment of primary bacterial sinusitis?
- Treatment to establish drainage and eliminate infection
- Promote mucociliary clearance: Mucolytics, inhalations, feeding at floor level, exercise and antibiotics can all be used
- Many resolve spontaneously
How would you manage primary bacterial sinusitis that is not responding to medical management?
- Irrigation and drainage via trephine (or pin)
- Frontal/maxillary flap if inspissated pus (hard, accumulated infection) to physically remove it - can be done standing
Prognosis of primary bacterial sinusitis?
Good
When does secondary bacterial sinusitis tend to occur?
- Usually older horses
- Most often secondary to dental disease e.g. dental fracture, periodontal disease (periapical abscessation)
Diagnosis of secondary bacterial sinusitis?
- Physical examination (esp look for systemic diseases e.g. PPID)
- Oral examination and dental assessment
- Endoscopy (discharge from nasomaxillary opening)
- Radiography (fluid lines and dental disease)
- CT to evaluate tooth roots directly.
Treatment of secondary bacterial sinusitis?
- Treat primary disease
- Remove diseased teeth
- Pack oro-nasal fistulae
- Irrigation and antibiotics
What other conditions might you see in the paranasal sinuses?
- Fungal granulomas
- Ethmoidal haematomas
- Squamous cell carcinoma
- Other neoplasia is less common
How does secondary mycotic sinusitis develop?
Occurs as a result of sequestra, chronic antibiotic administration, surgery, underlying debilitating disease
Clinical signs of mycotic sinusitis?
- Typically a destructive malodorous condition, that destroys the normal structure of the paranasal sinuses
- Nasal discharge
- +/- haemorrhage
Diagnosis of mycotic sinusitis?
- Sinoscopy/endscopy
- Radiographs may be unremarkable
- Especially if early mycotic disease
- If chronic may see significant changes due to structural damage
Treatment of mycotic sinusitis?
- Eliminate underlying cause (or treat – eg PPID)
- Physical lavage, then…
- Lavage with topical antifungal agents (e.g. Enilconazole)
- Prolonged treatment (4-6 weeks)
Prognosis of mycotic sinusitis?
Good prognosis if treated adequately and not significant structural damage
Clinical signs of mycotic rhinitis?
Malodorous purulent / sanguinous discharge
How does mycotic rhinitis occur?
- Occurs from within the nasal cavities themselves
-
Aspergillus fumigatus
- In plants inc hay and straw.
- Secondary to trauma?
Diagnosis and treatment of mycotic rhinitis?
- Serology is unreliable.
- Topical treatment with nystatin or natamycin (powders)
- Or endoscopically flush the cavities
Potential sources of bilateral epistaxis?
- Lungs
- Exercise induced pulmonary heamorrhage – variable amounts (esp. racehorses/performance horses)
- Lung neoplasia – variable, usually small amounts
- Pharynx
- Trauma, foreign body – variable, usually small amounts
- Guttural pouch mycosis - large amounts
Potential sources of unilateral epistaxis?
- Pharynx
- Guttural pouch mycosis - large amounts
- Sinus
- Mycotic sinusitis – usually small amounts
- Trauma – usually small amounts
- Nasal Cavity
- Progressive Ethmoidal Haematoma – usually a slow trickle
- Clotting abnormalities – usually slow and intermittent
- Trauma
How does iatrogenic epistaxis usually occur?
- Usually a result of passing stomach tube into middle meatus
- Should always go via the ventral meatus
- Can be a significant amount of blood
How should you manage iatrogenic epistaxis?
- Care with passing tubes, well lubricated and care when removing the tubes too.
- Will stop with time
- Always warn owners that it may happen before passing anything
- Hold head up
- Avoid drugs to lower blood pressure (eg ACP)
Which structures can be affected by gutteral pouch mycosis?
- Usually affects internal carotid (medial compartment)
- may be external or maxillary artery (lateral compartment)
- cause tissue trauma and erodes into the blood vessels, usually not massive haemorrhage initially
- may be a bilateral condition - check other GP
Clinical signs of gutteral pouch mycosis?
- Epistaxis: usually 1-3 episodes mild bleeding before the entire vessel ruptures - FATAL
- Neurological dysfunction: facial nerve, laryngeal or pharyngeal paralysis, vagal signs
Diagnosis of gutteral pouch mycosis?
- Diagnosed most commonly by endoscopy
- haemorrhage from guttural pouch ostia
- DO NOT ENTER POUCH - REFER AND LET THEM DO IT!
- Radiography
- If you can see fluid lines in GP indicates there may be significant haemorrhage
Immediate management of gutteral pouch mycosis?
- Emergency due to potential for fatal haemorrhage
- Very spontaneous and die very fast
- REFERRAL
- (Temporary cut down and occlusion of carotid can be used as in severe haemorrhage)
Treatment of gutteral pouch mycosis?
- Optimal treatment - surgical
- Ligation and balloon occlusion of affected artery (on both sides of the fungal lesion)
- Retrograde flow occurs therefore balloon occlusion recommended
How does PCV alter in the horse following acute blood loss?
- Initially…Loss of whole blood so no change in PCV or TP in first 4 hours
- After this, splenic contraction in response to hypoxia causes increase in PCV, and increase in circulating RBC
- Then, fluid recruited from Extracellular fluid, causing decline in TP and possible decline in PCV 4-6h
- PCV changes not appreciated for 12-24 hrs
Why do we have to take a bone marrow aspirate or biopsy in horses to classify their anaemia?
Horses do NOT release immature RBCs (stay in bone marrow)
How does a bone marrow sample differentiate anaemia in the horse?
- Determination of MYELOID cells
- Determination of ERYTHROID cells
- Ratio between them different in different anaemias
How would you get a bone marrow sample in the horse?
- Hollow needle, around a 12G, firm and hollow trochear
- Drive into sternum to sample the bone marrow
- Examined by clinical pathologist to determine the anaemia type.
