Lecture 3 Flashcards
Dyspnea present?
- Severity
- Oxygen dependent?
- Localization
- Inspiratory vs. expiratory vs. restrictive
- Upper airway, lower airway, parenchymal, thoracic wall, neurologic, abdominal (or not dyspnea…)
Cough mechanism
PROTECTIVE!!
- works w/ mucociliary apparatus
- both are less effective w/ disease!
NOTE: the trachea and large airways have the most “cough receptors”
Coughing
Coughing is a non-specific clinical sign ==> an accurate medical history is critical!
- acute vs chronic, static vs worsening, associations (ie. after exercise), productive vs. non-productive, other systemic signs
Potential coughing triggers
- owner is a smoker
- perfume/air fresheners
- dusty kitty litter
- house construction
Especially dig for some of these if patient has a cough history w/ no systemic disease or sign of infectious pneumonia
Coughing patient?
Consider any environmental exposure
- boarding/grooming?
- obtained from shelter?
- outdoors? travel history?
- walks? dog parks?
- show? agility competitor?
- heartworm prevention?
- other sick/coughing animals at home?
Physical exam components of coughing patient
- Tracheal and cervical palpation
- Nasal discharge (nasal discharge w/ lots of drainage ==> drainage may irritate the trachea and cause cough)
- Changes in weight
- Skin lesions
- Cardiac abnormalities
- Lymphadenopathy
- Fundic examinations (ocular lesions may be seen w/ fungal and neoplastic disease)
- Rectal examination
Characteristics of a non-productive cough
- Usually loud, harsh, and paroxysmal
- “Goose-honk” - Most commonly associated with:
- Upper airway disease (trachea and mainstem bronchi)
Productive cough
- Expectoration of sputum
- Fluid/mucus/debris from the LOWER AIRWAYS (not much mucous/fluid is produced in upper airway)
- Most commonly associated with:
- Lower airway disease
- Pulmonary parenchymal disease
NOTE: productive cough yielding a foamy expectorant: foamy is associated w/ edema or heart failure
NOTE 2: Are they coughing and then just swallowing? Are they swallowing their “productive cough”???
Productive cough characteristics
- Typically softer in volume (“huff”)
- Less likely to be “paroxysmal”
- May be difficult to appreciate
- Swallows sputum
- Owner perceives as vomiting
Terminal retch = NOT productive typically
Cats coughing?
Coughing in cats is RARE
- When present should pursue aggressively!!
- Most common cause of coughing in cats is LOWER AIRWAY DISEASE (asthma)
- Pleural space disease (rare)
- Tracheal disease (uncommon)
- Most common cause of coughing in cats is LOWER AIRWAY DISEASE (asthma)
Cardiogenic Cough
- Implies congestive heart failure… usually
- Pulmonary edema
NOTE: Which abnormal breath sound should you be able to auscultate during your exam w/ cardiogenic cough?
- CRACKLES.
CHF: significant mitral valve disease ==> may lead to enlarged Left Atria ==> may compress mainstem bronchi ==> may see an upper airway non-productive cough (unless CHF is so severe there is pulmonary edema)
Cardiogenic Cough
- Cough classically worse at night
- Typically exhibit concurrent exercise intolerance at rest
- May have auscultation abnormality (ie. murmur)
- Perihilar edema on radiographs
- Furosemide responsive
Non-cardiogenic cough
- Upper (large) airway
- Lower (small) airway
- Parenchymal
- Pleural Space
Upper Airway Cough: infectious
Infectious (tend to be honking, loud, non-productive)
- Infectious tracheobronchitis
- Parasitic (Oslerus osleri - filaroides) => K9 lungworm
- Hilar lymph node enlargement (squishes carina; Fungal disease - especially histoplasmosis)
NOTE: upper airway coughs tend to be non-productive
Upper airway cough: non-infectious
Non-infectious
- Tracheal collapse
- Compressive masses (mural or extra-mural)
- Foreign bodies
Lower Airway Cough
- Inflammatory airway disease
- K9 chronic bronchitis
- Feline lower airway disease
- Eosinophilic bronchopneumopathy
- Smoke/chemical irritant inhalation
Parenchymal Disease Cough: infectious
Infectious
- Bacterial
- Fungal disease (blastomyces, histoplasma, coccidioides)
- Heartworm infection
- Parasitic (Aleurostrongylus -cats, Filaroides hirthi -K9, Paragonimus -lung fluke)
- Toxoplasma (more common in cats)
Parenchymal disease cough: non-infectious
Noninfectious
- Neoplasia
- Primary (caudal lung lobes)
- Metastatic (multiple nodules) - Lung lobe torsion (concurrent pleural effusion)
- Non-cardiogenic pulmonary edema (strangulation and electrocution are the top 2 causes)
Diagnostic Plan: 1st tier tests
Common “first tier” tests
- CBC (look for inflammatory change)
- Thoracic radiographs (if stridor, stertor, goose-honk we’re thinking possible extra-thoracic so may want cervical rads)
- Fecal exam (float, sediment, Baermann)
- Heartworm testing
- Cytology (skin lesions, nasal discharge, lymph nodes)
Diagnostic Plan: 2nd tier tests
Second tier testing
- cardiac evaluation
- chem panel (helps if there’s systemic disease - like fungal - may have infiltrated liver and increased enzymes)
- Urinalysis (fungal antigen titers)
- AIRWAY SAMPLING (TTW, ETW, BAL)
- Advanced imaging (fluoroscopy, CT)
- Lung aspirate/biopsy
- Bronchoscopy/thoracotomy
Transtracheal and endotracheal wash
- When there is diffuse disease! (ie. bronchitis)
- instill 0.5-1.0 ml/kg per aliquot (repeat 2-3 times)
- catheter usually goes to the level of the carina (may go deeper w/ ETW)
- Recovered saline wash sample submitted for cytology and culture
NOTE: patient must be able to cough ==> consider when choosing anesthetic/sedative drugs
Bronchoalveolar Lavage (BAL)
BAL:
- LOCALIZED disease
- At least to 1 hemi-thorax (ie. right-sided aspiration pneumonia)
- Sample taken via guidance of bronchoscope - scope lodged in lower airway
- can take localized samples and can get greater volume yields
- patient may be oxygen-dependent until the patient coughs the saline up
Empiric antibiotic therapy possible?
- Limited to 1 course (failure = airway sampling necessary)
- Discontinue 1-2 weeks before sampling airways, if possible
- Informed client consent (may complicate future diagnosis/tx if unsuccessful)
Antitussives
- Opioids
- Butorphanol (torbugesic)
- Hydrocodone (combined w/ anticholinergic)
- Loperamide (Imodium)
- Diphenoxylate (also combined w/ anticholinergic) - Opioid derivative
- Dextromethorphan (OTC)
SIDE EFFECTS expected: sedation, constipation
Points to Ponder!
- Cough is a PROTECTIVE MECHANISM
- am I treating the patient or the owner? Is the cough interfering w/ quality of life in a big way?
- what are my top differentials?- Collapsing trachea? Bronchitis?
Relative CONTRAINDICATIONS:
- Productive cough
- Infectious disease present
