Sams Respiratory Learning Objectives

Front 1

DDx-Inspiratory dyspnoea

Back 1

-UPPER AIRWAY OBSTRUCTION(stridor)
-pulmonary fibrosis
-pleural/mediastinal disease (absence of stridor)

Front 2

DDx-Expiratory dyspnoea

Back 2

-chronic bronchial disease (e.g feline asthma)

Front 3

General Diagnostic approach to respiratory disease

Back 3

Before stethoscope:
1. history (chronicity)
2. observe breathing from distance
3. observe for ocular/nasal discharge
4. assess jugular veins, pulses, abdominal fluid, palpate chest, maximum loudness of heart
5. assess for non-respiratory disease

Front 4

DDx-sneezing/nasal discharge

Back 4

1. Fungal: aspergillosis, cryptococcosis
2. Neoplastic: common epithelial tumours(adenocarcinoma, undiff. carcinoma, SCC), common mesenchymal tumours(osteosarc, chondrosarc), Round cell tumours (lymphoma, MCT, TVT, histiocytoma)
3. Inflammatory-lymphocytic-plasmacytic rhinitis
4.
Parasitic
5. Misc: FB, Pneumonia, 'chronic snufflers'

Front 5

DDx-reverse sneezing

Back 5

=CAUDAL NASOPHARYNGEAL disease
-FB
-lymphocytic-plasmacytic or allergic pharyngitis/rhinitis

Front 6

DDx-Epistaxis

Back 6

1. Local:
-neoplasia
-fungal infection
-trauma
-FB
-nasal polyps (cats)
2. Systemic
-coagulopathy
-systemic hypertension
-polycythaemia
-hyperviscosity

Front 7

Diagnostic approach to sneezing/nasal discharge

Back 7

1. History (chronicity, vaccination status, progression (if any), other resp. signs, nature of discharge)
2. Physical Exam:
-facial/nasal asymmetry?
-nasal depigmentation?
-bilateral?
-pain?
-examine oropharynx

Front 8

Diagnostic approach to sneezing/nasal discharge
-Further workup

Back 8

bilateral epistaxis: coagulation profile, platelet count, BMBT, TS, BP
-assess for metabolic disease if unwell
-fungal serology
-GA: examine teeth,
radiography
rhinoscopic evaluation
tissue biopsy
nasal flushing

Front 9

Nasal aspergillosis
-organism

Back 9

Aspergillosis fumigatus

Front 10

Nasal aspergillosis
-CS

Back 10

-serosanguinous discharge that becomes mucopurulent (may also develop epistaxis-vascular necrosis)
-unilateral->bilateral
-ulceration of external nares
-pain and discomfort in facial region

Front 11

Nasal aspergillosis
-Dx

Back 11

-Radiography (CT)-extensive turbinate destruction w/ frontal sinus involvement in ~80% of dogs
-Rhinoscopy (turbinate destruction and fungal plaques)
-Dx confirmed by biopsy and tissue culture

Front 12

Nasal aspergillosis
-Tx

Back 12

Topical treatment (clotrimazole infusion):
1-2 treatments of 1hr under GA
+/- depot cream
NB: Neurotoxic so DO NOT USE if destruction of cribiform plate
DEBRIDEMENT ESSENTIAL

Front 13

Nasal aspergillosis
-Prognosis

Back 13

-good
-more than one treatment may be required
-small amounts of serous drainage may remain persistant

Front 14

Nasal Neoplasia
-CS

Back 14

-sneezing
-nasal discharge
-epistaxis
-may progress to stertor due to obstruction, decreased airflow through nostrils, facial deformity

Front 15

Nasal Neoplasia
-Dx

Back 15

-radiography(CT)=lack of symmetry,INCREASED RADIODENSITY, nasal discharge with loss of bony/turbinate detail (vomer/facial bone destruction)
-needs biopsy for confirmation

Front 16

Nasal Neoplasia
-Tx

Back 16

-lymphoma and TVT most responsive to chemotherapy
-piroxicam (reduce inflammation, may have anti-tumour efficacy against some carcinomas)
-Tx of choice=radiation therapy
-Sx not indicated

Front 17

Differences between nasal neoplasia and aspergillosis

Back 17

-Neoplasia rarely painful and rarely shows ulceration of the nares
-soft tissue changes tend to result in increased radiopacity in neoplasia vs. radiolucency w/ aspergillosis
-Neoplasia=caudal
-Aspergillosis=rostral
-Neoplasia=older
-Aspergillosis=younger

Front 18

Lymphocytic-Plasmacytic rhinitis
-diagnostic criteria

Back 18

Diagnosis of exclusion
CS-sneezing, bilateral nasal discharge
Dx-biopsy confirmation (must be BILATERAL)

Front 19

Stertor indicates? DDx?

Back 19

-indicates obstruction in the caudal nasopharynx
DDx:
-neoplasia (e.g. tonsillar SCC)
-nasopharyngeal polyps
-oedema
-inflammatory/infectious soft tissue masses (e.g aspergillomas)
-hyperplastic tissue as in brachycephalic syndrome

Front 20

Stridor indicates?

Back 20

Laryngeal disease (e.g. laryngeal paralysis)

Front 21

Diagnostic Approach to inspiratory distress w. no evidence of pleural effusion?

Back 21

-Clinical Exam
(prepare for emergency tracheostomy)
-IV catheter (anaesthetise quickly)
+/- sedation and oxygen therapy
-not distressed: full physical exam w/ neuro assessment
STRIDOR main presenting sign:
-lightly anaesthetise and perform laryngoscopy-visualise glottis and observe movement of arytenoids
STERTOR main presenting sign:
-examine soft palate and caudal oropharynx while anaesthetised
+/- thoracic radiographs to assess for concurrent pulmonary/mediastinal disease

Front 22

5 Components of Brachycephalic Airway Syndrome

Back 22

-stenotic nares
-elongated soft palate
-everted laryngeal saccules
-laryngeal collapse
-tracheal hypoplasia (English Bulldogs)

Front 23

BAS
-Tx

Back 23

-Emergency Treatment: nasal oxygen, anti-inflammatory doses of parenteral glucocorticoids (IV dex), cage rest
-ensure hyperthermia does not develop
-emergency tracheostomy may be necessary
-once stable: surgical correction of abnormalities:
-resection of soft palate;
-excision of laryngeal saccules
-partial laryngectomy
-temporary tracheotomy
-temporary/permanent tracheostomy
-excision of nares
-arytenoid lateralisation

Front 24

Laryngeal Paralysis
-Causes

Back 24

-congenital, anterior thoracic lesion, polyneuropathy, polymyopathy
-most commonly IDIOPATHIC in older, large breed dogs>neurogenic atrophy of laryngeal muscles and Wallerian degeneration of recurrent laryngeal nerves

Front 25

Laryngeal Paralysis
-CS

Back 25

-respiratory distress w/ significant STRIDOR
-exacerbated by hot weather, exercise, excitement

Front 26

Tracheal Disease:
-CS

Back 26

-dry, hacking, cough and/or dyspnoea
-dyspnoea is inspiratory if extra-thoracic portion of trachea affected

Front 27

Tracheal Collapse
-primary defect
-secondary/exciting factors

Back 27

-intrinsic weakness of tracheal rings (poss. congenital)
-obesity, hyperA, allergic airway disease, resp. infection, recent intubation, cardiomegaly +/- pulmonary oedema; perpetuated by coughing and cycle of chronic inflammation

Front 28

Tracheal Collapse
-CS

Back 28

-harsh paroxysmal coughing (induced on exam, exacerbated by excitement)
-'goose-honk' cough
-respiratory distress if severe
-+/- cyanosis and extreme resp. distress

-primary problem: slow heart rate w/ pronounced sinus arrhythmia (increased vagal tone from chronic airway disease)

Front 29

Tracheal Collapse
-Dx

Back 29

-Radiographs (insp/exp.-narrowed or variable diameter of tracheal lumen) DO NOT INTUBATE
-fluroscopy (bronchial collapse)
-endoscopy (loose dorsal ligament folding into lumen and flattened cross section)+/- BAL

Front 30

Tracheal Collapse
-Tx

Back 30

-Acute (resp. distress):
(anxious) sedate (opioids also have anti-tussive actions: acepromazine and methadone)
oxygen
short term corticosteroids may reduce tracheal or laryngeal oedema
-Chronic: rule out underlying disorders, weight loss, anti-tussives (codeine), minimise excitement, chest harness and restrict exercise

Front 31

Initial approach to the dog with cyanosis or respiratory distress

Back 31

1. observe then stabilise (O2 and sedation)
2. IV catheterisation
3. determine if upper airway obstruction or noise
-then rule out pleural space disease
4. if pulmonary parenchymal disease most likely, then perform full physical exam
(treat for CHF if necessary w/ IV frusemide)

Front 32

6 causes of arterial hypoxemia

Back 32

1. decreased inspired oxygen concentration
2. alveolar hypoventilation
3. Ventilation-perfusion mismatch
(severe pulmonary parenchymal disease, increase in dead space)
4. Diffusion impairment
5. Shunt
6. Abnormal haemoglobin

Front 33

Initial Approach to cat w/ acute dyspnoea

Back 33

1. O2 supplementation and sedation +/- cursory examination
2. thoracocentesis until stable if pleural disease present
3. crackles or wheezes present-assess for presence of a gallop rhythm or heart murmur
-if CHF more likely give frusemide 1-2mg/kg IV
-asthma more likely give dex 0.25-0.5mg/kg IV

Front 34

Most common causes of acute respiratory distress in cats

Back 34

-asthma (feline bronchial disease)
-CHF
-pleural space disease

Front 35

DDx of coughing and/or dyspnoea

Back 35

1. Infectious: mycoplasma pnemonia (C & D), Heartworm
2. Allergic/Inflammatory: feline bronchitis/bronchial asthma; chronic canine bronchitis; pulmonary infiltrate with eosinophils (PIE)
3. Traumatic lung diseases: aspiration pneumonia
4. Neoplasia (primary)
5. Pulmonary thromboembolism
6. Enlarged left atria
7. Non-cardiogenic pulmonary oedema
8. Tracheal/bronchial collapse
9. pulmonary fibrosis

Front 36

Basic Non-specific Tx for airway disease (7)

Back 36

1. Antitussives
2. Protussives (e.g. mucokinetics)
3. Expectorants
4. Decongestants (sinusitis, reverse sneezing)
5. Aerosolisation
6. Oxygen therapy
7. Airway humidification

Front 37

Chronic canine bronchitis
-pathogenesis

Back 37

-chronic inflammation of conducting airways
-airway injury and repair-accumulation of mucous, reduced airflow>coughing

Front 38

Chronic canine bronchitis
-Diagnostic criteria

Back 38

-chronic cough
-excess mucous
-exclusion of other pulmonary diseases
-may result in chronic obstructive pulmonary disease (COPD)

Front 39

Chronic canine bronchitis
-possible underlying causes

Back 39

-atmospheric pollution
-passive smoking
-resp. tract infections
-genetic/acquired defects (immunodeficiency, mucocilary defects)
-hypersensitivity

Front 40

Chronic canine bronchitis
-CS

Back 40

-cough (dry, hacking) >2 months
-small breed dogs
-middle aged or older
-collapse/exercise intolerance (COPD)

Front 41

Chronic canine bronchitis
-PE

Back 41

-overweight
-systemically well
-crackles on thoracic auscultation (normal at rest)
-increased tracheal sensitivity
-severe disease: dyspnoea (expiratory effort/ 'push') or cyanosis
-sinus arrythmia (increased vagal tone)

Front 42

Chronic canine bronchitis
-Dx

Back 42

-exclusion of all other causes
Rads: increased bronchial interstitial pattern (difficult in older animals)
Bronchoscopy: reddened, rough airways w/ increased mucous
BAL: increased inflammation (non-degenerate neutrophils) +/- increased mucous and squamous metaplasia

Front 43

Chronic canine bronchitis
-Tx

Back 43

-Anti-inflammatory drugs-glucocorticoids sparingly at low doses
-Bronchodilators-theophylline (improves muco-cilary clearance)
-Adjunctive therapy-weight loss, decrease environmental allergen, harness walking, airway humidification and coupage
-Anti-tussives: Do not use if there is excess mucous or evidence of inflammation
-Anti-biotics: doxycycline (followed by enrofloxacin, beware with concurrent theophilline=toxicity)

Front 44

Pulmonary fibrosis
-CS

Back 44

-WHWT, SBT
-middle aged, older
-SLOW onset
-coughing/tachypnoea/DYSPNOEA (inspiratory)/may become cyanotic

Front 45

Pulmonary fibrosis
-PE

Back 45

-distinctive inspiratory crackles (some as wheezing as well) 'velcro lungs'
-often systemically well
-obese
-+/- bradycardia/ sinus arrhythmia

Front 46

Pulmonary fibrosis
-Dx

Back 46

1. Thoracic radiographs: increase interstitial pattern, bronchial pattern, right sided heart enlargement (cor pulmonale)
2. Bronchoscopy: mild increase in mucous seen, may get roughening and thickening of mucosal surface
3. BAL: normal cell numbers or minimal inflammation in most samples.

Front 47

Pulmonary fibrosis
-Tx

Back 47

-immunosuppressive doses of glucocorticoids, bronchodilators, colchine (anti-fibrotic) and antibiotcs
-no single treatment protocol
-prognosis poor but survival up to 3 years after diagnosis had been reported

Front 48

Eosinophillic Bronchopneumopathy (EBP)
-CS

Back 48

-cough, gagging and retching
-dyspnoea
-Malamutes and Huskies

Front 49

Eosinophillic Bronchopneumopathy (EBP)
-Dx

Back 49

-moderate to severe bronchinterstitial pattern on radiographs
-peripheral eosinophillia in 50-60%
-BAL usually eosinophillic *CYTOLOGY*

Front 50

Eosinophillic Bronchopneumopathy (EBP)
-DDx

Back 50

-HEARTWORM
-parasitic disease (esp. if a component of hypersensitivity)
-bronchopneumonia
-neoplastic disease

Front 51

Eosinophillic Bronchopneumopathy (EBP)
-Tx

Back 51

-immunosuppressive doses of corticosteroids
-reasonable prognosis, but may recur

Front 52

Bacterial Bronchopneumonia
-CS

Back 52

-mature, immune competent dogs
-must always look for underlying cause
-soft, grunting cough (parenchymal)
-dyspnoea, pyrexia, signs of systemic illness
-+/- bilateral mucopurulent nasal discharge

Front 53

Bacterial Bronchopneumonia
-Dx

Back 53

-CBC: neutrophillic leucocytosis +/- left and toxic changes
-Rads: interstitial pattern early, alveolar patten develops as disease progresses
-BAL: septic process (TTA if unstable)
-culture aerobically and anaerobically

Front 54

Bacterial Bronchopneumonia
-bacteria in dogs

Back 54

-aerobic gram negative and obligate anaerobes:
E. coli, Strep, Pasteurella, Klebsiella pneumoniae, pseudomonas aeruginosa, bordetella bronchiseptica, staph spp. obligate anaerobes

Front 55

Bacterial Bronchopneumonia
-bacteria in cats

Back 55

-bacteria from the oral cavity:
Moraxella spp., Pasteurella multicoda. Strep, E. coli, Klebsiella pneumoniae, B. bronchiseptica, Proteus spp.

Front 56

Bacterial Bronchopneumonia
-Tx

Back 56

-a/b therapy based on C+S
(stable: clavulox, triprim; unstable disease: cefazolin/ enrofloxacin SC)
-systemic fluids and nebulisation
-oxygen as required
-regular thoracic coupage
-mucolytics

Front 57

Aspiration Pneumonia
-pathogenesis

Back 57

-loss of protective mechanisms/ iatrogenic (upon anaesthetic recovery)
-Phase 1 Airway response: direct chemical burn and stimulation sensory nerves in airway
-Phase 2 inflammatory response: 4-6 h post aspiration
-Phase 3: bacterial superinfection or aspiration

Front 58

Aspiration Pneumonia
-Dx

Back 58

-history
-increased crackles in affected lung fields
-radiography: intersitial (early) to bronchial-alveolar pattern (later)
(mineral oil aspiration in cats: diffuse, nodular, interstitial pattern that can mimic neoplastic, fungal or parasitic disease

Front 59

Aspiration Pneumonia
-Tx

Back 59

-Supportive: oxygen, fluid therapy as required, suctioning if indicated, bronchodilators first 24-48 hours after witnessed aspiration
-a/b therapy: culture results, only chronic cases (not witnessed), triprim, clavulox minimum 3-4 weeks

Front 60

Approach to diagnosis of inspiratory dyspnoea w/o stertor/stridor

Back 60

-clinical signs consistent with pleural space disease=thoracocentesis + cytology of fluid (+/- culture)
-thoracic auscultation and chest percussion
-rads: retraction of lung lobes, thickening of fissures, heart shadow obscured)
-U/S
-FNA4 basic

Front 61

Mediastinal disease:
-CS

Back 61

-dyspnoea
-abnormal location of cardiac impulse
-Horner's syndrome

Front 62

Pleural space disease:
-CS

Back 62

-dyspnoea w/ inspiratory effort/ difficulty
-muffled breath sounds
-displacement of heart sounds or abnormal sounds in the thorax (e.g. borborygmi-diaphragmatic hernia)

Front 63

4 basic mechanisms by which pleural fluid accumulates in abnormal quantities:

Back 63

-increased capillary hydrostatic pressure (CHF)
-decreased capillary oncotic pressure (hypoalbuminaemia)
-increased capillary membrane permeability (inflammation)
-lymphatic obstruction (neoplasia)

Front 64

Classification of pleural effusions:

Back 64

-pure transudate (hypoproteinemia)
-modified transudate (increased hydrostatic pressure [RSCHF]; decreased oncotic pressure; lymphatic obstruction)
-Exudates (non-septic; septic; chyle; haemorrhage)

Front 65

DDx Pleural effusion

Back 65

PURE TRANSUDATE: hypoalbuminaemia (liver disease), IV fluid overload (cats)
MODIFIED TRANSUDATE: RSCHF, pericardial disease, diaphragmatic hernia, neoplasia, LSCHF in cats
NON-SEPTIC EXUDATES: FIP, neoplasia, chronic diaphragmatic hernia, lung lobe torsion, pancreatitis, resolving septic exudates
SEPTIC EXUDATE: pyothorax
CHYLE: heart disease, neoplasia, congenital, traumatic, lung lobe torsion, cranial mediastinal mass, idiopathic, diaphragmatic hernia
HAEMORRHAGE: trauma, coagulopathy, neoplasia, lung-lobe torsion, pulmonary infarction

Front 66

Underlying causes of chylothorax in cats (in order of likelihood)

Back 66

1. CHF (cats)
2. Cranial Mediastinal Mass
3. Idiopathic

Front 67

Pyothorax:
definition?
more common in?

Back 67

-accumulation of pus in the pleural space
-more common in cats

Front 68

Differences between pyothorax in cats and dogs.

Back 68

Cats:
-facultative and obligate anaerobes
-aetiology unknown (bite wounds, dental disease, mediastinal perforation, migrating foreign body, extension of bacterial pneumonia)

Dogs:
-Actinomyces or Nocardia causative organisms
-migrating foreign body (grass seed tracking infection, extension of pneumonia)

Front 69

Pyothorax:
Tx

Back 69

DRAINAGE OF FLUID:
-bilateral chest drains under GA
-warm saline instilled in chest, rolling/walking
+/- thoracotomy
-a/b based on culture and sensitivity of fluid (dogs w/ actinomyces-penicillins nocardia-trimethoprim sulfa, tetracyclines, aminoglycosides)

Front 70

Mediastinal Mass
-DDx

Back 70

-primary mediastinal tumours (lymph nodes, thymus, aortic body chemoreceptors, ectopic thyroid tissue)
-benign masses (cystic)
-fat deposition (fat animals)