Thoracic And Resp Surgeries Flashcards
What part of the airway is the primary source of resistance to airflow?
The upper airway - nasal valve, rostrum nasopharynx, and larynx, oral cavity (tremendous resistance)
What occurs in the instance of upper airway dysfunction?
Incr resistance > decr ventilation > Poor performance; incr turbulence > incr noise
What are common presenting complaints for horses with upper airway issues?
Noise (inspirations vs. expiratory), poor performance, nasal discharge, cough, dysphagia, halitosis, anatomical distortions, fever, inappetence, weight loss
What are three tests for laryngeal function at rest?
Nasal occlusion, swallow reflex, and the slap test
What might you look at with laryngeal endoscopy when the patient is exercising?
Dynamic dysfunction; would do this on a high speed treadmill or overground exam
What are some indications for sinoscopy?
Old age, minor surgical procedures
What are you looking at with cranial radiographs? What is the biggest set back of this diagnostic method?
Paranasal sinuses and dental arcades primarily, but also at the guttural pouches, pharynx, larynx, and trachea; check for fluid lines, ST/fluid opacity; biggest set back = superimposition!
What body part are you limited to for ultrasonography in equines and why is this the case?
Larynx - bone limits most other locations; checking for abnormal anatomy (congenital, distortion d/t dz, muscular atrophy)
What are the benefits of CT scans?
No superimposition! - imaging method of choice, typically used for looking at dental arcades and paranasal sinuses
What are MRIs good for?
Soft tissue detail, +/- contrast
What are a couple other diagnostics for respiratory disease in equines?
Nuclear scintigrapy, clinical pathology (CBC/Chem), microbial culture and sensitivity, bronchoalveolar lavage, histopath
What are some potential diseases of the nasal passage?
Epidermal inclusion cysts (atheromas), redundant alar folds, nasal lacerations, nasal septal dz (cysts, neoplasia, trauma), engorgement of the nasal mucosa (Horner’s syndrome), wry nose
What are some diseases of the paranasal sinuses?
Sinusitis (primary, secondary), sinus cyst, ethmoid hematoma, neoplasia, trauma (fractures and wounds)
What are the causes of primary vs. secondary sinusitis?
Primary - usually Strep. Sp.; Secondary - dental dz, mass, trauma
How do you diagnose sinusitis?
Endoscopy (drainage from middle meatus), rads (fluid lines, space occupying lesion), CT, sinocentesis (culture and sensitivity), sinoscopy
What are your treatments for primary and secondary sinusitis?
Primary - lavage (trephine), abx, +/- sx debridement; Secondary - address the CAUSE!, tx as primary sinusitis
What are your landmarks for trephination of the frontal sinus?
Draw a line from midline to medial canthus; 60% of distance from midline along this line and 0.5 cm causal to the line
What are your landmarks for trephination of the caudal maxillary sinus?
2 cm ventral to medial canthus
What are you landmarks for trephination of the rostrum maxillary sinus?
Draw a line from medial canthus to infraorbital foramen, 1 cm ventral to this line and midway b/t the medial canthus and the rostrum extent of the facial crest
What is a paranasal sinus cyst?
Fluid filled mass, enlarge > facial deformation, sinusitis, +/- airway obstruction
How do you diagnose and treat paranasal sinus cysts and what is the prognosis for these?
Dx: C/S, endoscopy, rads, sinocentesis, CT, histopath
Tx: Sx debridement
Px: Excellent
What is the most common type of sinus neoplasia and what are some common clinical signs?
Sinus neoplasia is rare, but SCC is most common; C/S include facial deformation, +/- airway obstruction, often dx late in dz process
How do you diagnose and treat sinus neoplasia and what is the prognosis?
Dx: C/S, endoscopy, rads, biopsy (sinoscopy), CT, MRI; Tx: sx debridement, radiation, chemo; Px: usually poor unless benign
What are progressive ethmoid hematomas?
Masses arising from ethmoids or sinus, causing mild intermittent epistaxis (unilateral > bilateral), facial deformation and significant airway obstruction = RARE
How do you diagnose and treat progressive ethmoid hematomas and what is the prognosis?
Dx: endoscopy, rads, +/- CT; Tx: intralesional 10% formalin, LASER photoablation, sx removal (sinus); Px: good but recurrence not uncommon
What are common clinical signs of trauma to the paranasal sinuses?
Open vs. closed, depression fx, epistaxis, emphysema, dyspnea, CNS signs, check the eye!
How do you diagnose and treat paranasal sinus trauma and what is the prognosis?
Dx: rads, CT, endoscopy; Tx: stabilize patient, abx, analgesia, wound tx, sinus lavage, surgical repair; Px: good for healing, dependent on concurrent problems
What is lymphoid hyperplasia caused by, what are the clinical signs of it, and should you be worried about it?
Immune stimulation, C/S = typically none, often in young horses; rarely need treatment, just rest the horse and maybe give anti-inflammatories
What are the clinical signs of cause of dorsal displacement of the soft palate?
C/S: noise during expiration; Intermittent > persistent
Cause? = persistent - CNS/PNS dz
What are diagnostics and treatments for dorsal displacement of the soft palate? What is the prognosis of this?
Dx: resting endoscopy, exercising endoscopy, +/- rads, +/- U/S; Tx: conservative = tongue tie, figure 8 noseband, sx = laryngeal tie-forward, ST myectomy/tenectomy, palatoplasty?; Px: 60%, up to 80-90% for tie-forward in Standardbred racehorses
Describe recurrent laryngeal neuropathy
Demyelination and axonopathy of the RLN, paresis > paralysis of intrinsic laryngeal mm (CAD - abductor), insp obstruction and noise at exercise, most often L side and in large horses (TB, draft)
How do you diagnose and treat recurrent laryngeal neuropathy? What kind of prognosis does the patient have?
Dx: laryngeal palpation (prominent muscular process), resting endoscopy! (Grade I-IV), laryngeal U/S, +/- exercising endoscopy; Tx: prosthetic laryngoplasty (tie-back), partial arytenoidectomy, neuromuscular pedicle graft, ventriculecotomy, vocalcordectomy; Px: tie-back - racehorse (50-70%), performance horse (85-95%)
What important vessels and nerve lie within the lateral compartment of guttural pouch? The medial compartment?
Lateral: External carotid > maxillary a. And facial n.; Medial: internal carotid a., cranial cervical ganglion, symp trunk, CN IX, X, XI, XII, pharyngeal branch of X
Describe guttural pouch mycosis
Rare but life threatening, focal fungal infection with predilection for vital structures, often Aspergillus sp.
What are the clinical signs for guttural pouch mycosis and how do you diagnose this?
C/S: epistaxis (DDx rupture of ventral straight mm), dysphagia, Horner’s syndrome, abn resp noise, nasal discharge; Dx: endoscopy!, +/- rads
What are potential treatments for guttural pouch mycosis and what is the prognosis?
Tx: medical tx fungus - slow, poor efficacy, hemorrhagic shock - transfuse, fluids, vascular occlusion - epistaxis cases, NSAIDs, nutritional support; Px: guarded, 50% of horses that hemorrhage die
What are some potential treatments for tracheal diseases?
Tracheotomy - provide airway for horses with life-threatening upper airway obstruction, emergency or pre-emotive, and permanent tracheostomy (good px)
How do you perform a tracheotomy?
Longitudinal incisions at level of junction of prod and mid 1/3 of the neck
Transverse incision b/t rings, <50% circumference
What are your indications for thoracic surgery?
Pleuritis, pleuropneumonia, pulm abscess, trauma, diaphragmatic hernia
