Respiratory Flashcards
Factors to pay particular attention to when localizing respiratory disease
- nasal discharge
- audible sounds other than cough
- cough
- auscultation
- breathing pattern
Stertor helps localize to where
upper airways-particularly pharynx
Stridor helps localize to where?
upper airways, particularly larynx
Vocal changes suggest localization to where?
larynx
Reverse sneezing helps localize disease to where?
upper airways-particularly nasopharynx/pharynx
Normal breathing rates at home and in exam room
at home: 12-18
in exam room: <30
Relatively slow rate for the degree of effort of breathing indicates:
large airway obstruction
Relatively fast rate (>50) indicates what in terms of trying to localize respiratory disease?
pulmonary parenchymal or pleural disease
More difficulty on inspiration + slow rate —> ?
extrathoracic obstruction
More difficulty on inspiration + fast rate –> ?
restrictive disease (loss of compliance, pleural space disease)
More difficulty during expiration –> ?
- intrathroacic obstruction
- intrathoracic large airway obstruction
- small airways (obstructive lung disease)
What are factors to evaluate to help determine the severity of respiratory compromise?
- effort (i.e. open mouth breathing in cats = marked compromise)
- exercise intolerance
- MM color
Compare and contrast how obstructive and restrictive disease may present
Obstructive: rapid rate, increased effort during expiration (listen for wheezes)
Restrictive: rapid rate, relatively increased during inspiration + expiration
What type of presentation is typical of pleural disease?
- decreased sounds on auscultation
- non-localizing signs
- exercise intolerance (i.e. tachypnea, relatively increased effort on inspiration)
Describe how a bronchial pattern looks
- Thickened airways look like railroad tracks or doughnuts
- Bronchiectatic airways are dilated without normal taper
What is an air bronchogram? What pattern does is it seen with?
- stripes without walls
- occurs with alveolar pattern
What causes an alveolar pattern?
overflow of fluid/exudate from the interstitium or airways into the alveoli
Describe a reticular pattern
- ill-defined density
- loss of detail of normal structures
- if mild, may be “normal” aging change
- can be early stage of alveolar or nodular
Types of interstitial patterns
- reticular
- nodular
- reticulonodular
- mass
What does a consolidated lung lobe indicated?
advanced interstitial or alveolar disease
- lung lobe torsion
- neoplasia
- severe, localized bacterial pneumonia
- granuloma
Which lung lobes are “gravity-dependent?”
the L and R cranial lobes and the right middle lobe
What is the purpose of thoracic radiographs for assessing respiratory disease?
- support history and PE findings
- furthur localization within lower respiratory tract
- assessment of severity of disease
- not assoc. with pulmonary function
- assessment of progress
Name four systemic fungal infections that can be detected by serology, and whether antibody or antigen is detected for each
- Blastomycosis: antibody
- Histoplasmosis: antibody
- Coccidioidomycosis: antibody
- crypococcosis: antigen
Besides systemic fungal infections, serolgy is useful to detect what else?
- heartworm
- need antigen and Ab test in cats
- toxoplasmosis (Ab)
- canine influenza (Ab)
Urine tests for fungal antigens are useful for which diseases?
Blasto, Histo
A minimum of how many fecal exams is needed for pulmonary parasites?
3
Respiratory parasite-eggs sink on sedimenation
Paragonimus
Respiratory parasite that can be detected on flotation
Capillaria
Larvae of ___________ are detected by a Baermann
Aelurostrongylus (cats)
Ddx for bronchial patterns
- canine chronic bronchitis (idiopathic)
- feline bronchitis (idiopathic)
- allergic bronchitis
- canine infectious tracheobronchitis
- bacterial infection
- mycoplasma infection
- pulmonary parasites (Aelurostrongylus, Capillaria, Oslerus)
Differentials for alveolar pattern
Pulmonary edema-often peri-hilar or caudo-dorsal distribution
Airway origin pneumonia(often cranioventral dist.)
- bacterial pneumonia
- aspiration pneumonia
Hemorrhage
- pulmonary contusion
- pulmonary thromboembolism
- neoplasia
- fungal pneumonia
- systemic coagulopathy
Differentials for interstitial patterns if also sever inflammation, edema, or hemorrhage
Name some differentials that often cause a nodular interstitial pattern
- blastomycosis
- histoplasmosis
- coccidioidomycosis
- paragonimus
- aelurostrongylus
- neoplasia
- eosinophilic lung dz (reticular, nodular, or both)
- abscess
Name some possible differentials for a reticular interstitial pattern
- mild pulmonary edema
- infectious
- viral pneumonia-canine distemper
- bacterial pneumonia
- protozoal pneumonia
- heartworm dz
- eosinophilic lung disease (can be reticular, nodular, or both)
- idiopathic interstitial pneumonia
- mild hemorrhage
Differentials for a vascular pattern
- Enlarged arteries
- heartworm
- PTE
- pulmonary hypertension
- Enlarged veins
- left-sided HF
- Enlarged arteries and veins
- left to right shunts
- small arteries and veins
- cardiovascular shock
- hypovolemia
- severe dehydration
- blood loss
- hypoadrenocorticism
- pulmonic valve stenosis
- hyperinflation of lungs
- feline bronchitis
- allergic bronchitis
Name forms of specialized radiography that might be indicated for diagnosing respiratory disease and why they are helpful
- Inspiratory neck/expiratory thorax films-for trachea and large airway collapse
- ultrasonography for masses against the body wall
- CT for increased detail and sensitivity
- Angiography, contrast CT, or nuclear imaging for PTE
Considerations for pulmoary specimen collection
- client capabilities/priorities
- top differential diagnoses
- localization within the lung
- risk of procedure balanced with condition of patient
What are the indications for a tracheal wash?
- bronchial and alveolar disease
- bacterial and aspiration pneumonia; chronic cough/bronchitis
- may consider for any lung disease because of safety and availability
Advantages of a trach wash
- simple
- minimal expense
- no special equipment
- complications are rare
- volume is adequate for cytology and culture
Disadvantages of trach wash
representative cells must be present in the large airways
Indications for a transthoracic lung aspiration
- solid masses adjacent to body wall
- diffuse interstitial lung disease
- best for diffuse nodular disease
Advantages of transthoracic lung aspiration
- simple
- minimal expense
- no special equipment needed; though US increases yield and decreases risk
- solid masses adjacet to chest wall: gives an excellent representation with minimal risk
Potential complications with transthoracic lung aspiration
- pneumothorax
- hemothorax
- pulmonary hemorrhage
Disadvantages of transthoracic lung aspiration
- complications
- relatively small area of lung sampled
- specimen only adequate for cytology
- specimen blood contaminated
Bronchoalveolar lavage is indicated for what type of disease?
interstitial
Advantages of NB-BAL
- minimal expertise and expense
- no special equipemtn
- hypoxemia is transiet and responsive to O2 in stable patients
- large volume of lung is sampled
- high quality cytologic specimen
- large volume for analysis
Disadvantages of NB-BAL
- not recommended for animals with increased respiratory effort or other signs of poor oxygenation
- general anesthesia required
- need access to oxygen/ventilation
What is the site of collection for thoracotomy + lung biopsy?
small airways, alveoli, interstitium
What are the advantages of thoracotomy + lung biopsy
- highest quality specimen plus potential for therapeutic benefit with focal disease
- ideal specimen
Indications for thoracotomy and lung biopsy
- localized process where exicsion may be therapeutic as well as diagnostic
- any progressive disease not diagnosed by less invasive means
Thoracotomy + lung biopsy disadvantages
- relatively expensive
- requires expertise
- requires general anesthesia
- major surgical procedure
Summarize approach to patient with lower respiratory tract disease
- localize to lower respiratory tract with history and PE
- critically evaluate thoracic radiographs and CBC for further localization and to prioritize differentials
- perform non-invasive tests as indicated by the list of differential diagnoses (fecal exams, blood tests, specialized radiographic techniques)
- collect pulmonary specimens
- continue to work through options until:
- obtain specific and complete diagnosis OR
- elect to refer OR
- determine that trial treatment is better than more diagnostics
Gold standard pulmonary function test
arterial blood gas
Why is arterial blood gas done?
- confirm pulmonary compromise (vs. dz)
- monitor progression of disease/response to therapy
- assess risk of procedures
- assess the need for oxygen supplementation
- assess the need for ventilatory support
Categories of pleural cavity disease
- pleural effusion
- pneumothorax
- mediastinal masses
- pneumomediastinum
What are some possible signs seen with pleural cavity disease?
- abnormal breathing, tachypnea
- fever
- anorexia
- palpable cranial thoracic mass (cats)
- cough! - cats with chylothorax
Chorioretinitis is associated with ______ in cats
FIP
What is the imporatnce of evaluating the thoracic radiographs after air/fluid removed?
- need full inspiration on thoracic rads to accurately evaluate; otherwise may look like pneumonia, masses, etc. that are really not there but it looks like that because the lung is not fully expanded
Name two situations where there might be a pleural effusion but you may not want to remove all the fluid/remove only as much as needed to stabilize patient
- if ultrasound is possible
- or if the fluid is blood; they can autotransfuse it
The major differential for a pure transudate is hypoalbuminemia. What are the major underlying causes to look for?
PLE, PLN, liver disease
If you see a nonseptic exudate in a cat, what is one concern?
FIP
If you have a nonseptic exudate, what are the next steps to evaluate for neoplasia?
- thoracic rads
- US
- CT
- thoracoscopy
- throacotomy
Diagnostic approach for septic exudate
- Gram stain
- aerobic culture (+/- anaerobic culture)
- Serial thoracic rads
Correct treatment of pyothorax
- Immediate stabilization
- thoracocentesis
- IV fluids (often needed if septic)
- treatment of the infection
- antibiotics (IV while in hospital, send home on long term oral)
- chest tube
- follow-through
- long term antibiotics
- radiographic monitoring
What factors give the best prognosis for pyothorax?
- survive the first day or two
- timely, aggressive treatment
How to prove chylothorax
TG measurements
TG fluid > TG serum/plasma
Chylous effusion differentials
- idiopathic
- traumatic
- will usu. resolve spontaneously
- anterior mediastinal mass
- neoplasia
- heart disease
- dirofilariasis
- pericardial disease
Management of chylothorax
- treat underlying disease
- intermittent thoracocentesis
- rutin (nutraceutical)
- fat restricted diet
- surgical exploration and palliation (NOT CURATIVE)
- thoracic duct ligation
- drains (fluid from thorax into abdomen or vessels)
- pericardectomy
Chylothorax prognosis
guarded
Differentials for a hemorrhagic effusion? What additional diagnstics are warranted for each?
- trauma–>hx, PE
- bleeding disorder–>PE, platelet count, coagualtion tests (ACT, PT, PTT)
- neoplasia –>thoracic radiographs, US, CT, thoracoscopy, thoracotomy
- lung lobe torsion–>thoracic rads, US, bronchoscopy, thoracotomy
Most common cause of acute nasal signs in cats
viral rhinitis (herpesvirus, calicivirus)
What are the two big concerns with acute nasal signs in dogs?
- possible foreign body
- possible exposure to “kennel cough”/influenza type organisms
If you suspect nasal foreign body, what should you do next?
immediate rhinoscopy, including retrograde exam of nasopharynx
What are the next appropriate steps if you suspect “kennel cough”?
- isolation
- rest, time
- +/- antibiotics
- monitor progress
What are the more common differentials for nasal bumps
- carnassial tooth root abscesses
- neoplasia-usually malignant
- cryptococcosis (cats)
Approach to nasal bumps
- fine needle aspiration
- cryptococcal titers (cats)
- work up as for chronic nasal discharge or external biopsy the mass
Do cats or dogs often have idiopathic chronic rhinosinusitis?
CATS
Most nasal diseases have what distribution?
focal or multifocal
Most bacterial infections of the nasal cavity are ________ (primary/secondary)?
SECONDARY
Lymphadenopathy might be indicated if you suspect what?
cryptococcus or neoplasia (carcinoma, lymphoma)
What is an agent that is associated with facial pain (fairly unique)
Aspergillus
How to diagnose cryptococcosis
nasal swab cytology
cryptococcal antigen test
What should be done in dogs and cats with nasal hemorrhage?
- CBC + platelet count
- coagulation times
- BMBT
- Rickettsial titers (dogs)
- arterial blood pressure
- Von Willebrand’s factor assay (dogs)
What to do for feline idiopathic chronic rhinosinusitis
- facilitate drainage
- vaporizer treatments, topical saline solution, nasal cavity flushes under anesthesia, topical decongestants(for acute flare ups)
- decrease environmental irritants
- control secondary bacteria
- Clavamox, doxy, azithromycin
- if improment noted in 1 wk, continue 4-6 weeks
- if signs recur after stopping, re-initiate SAME antibiotic, continue for months
- Clavamox, doxy, azithromycin
- treat possible herpesvirus
- lysine diet supplementation
- famciclovir
- reduce inflammation
- second generation antihistamine (cetirizine)
- oral prednsolone
- omega 3 supplementation
- N-acetylcysteine orally
- surgical intervention
- turbinectomy
- frontal sinus ablation
What to do for canine idiopathic chronic/lymphoplasmacytic rhinitis
- facilitate drainage
- vaporizer treatments
- topical saline solution
- decrease irritants in env
- control secondary bacterial infection
- long term antibiotics
- reduce inflammation
- oral prednisone
- omega 3 supp.
- oral N-aceylcysteine
- antihistamines
- surgical intervetion
Bronchodilators-use in emergency
- albuterol by MDI
- terbutaline injectable
- oral aminophylline or theophylline
What is a maintenance corticosteroid that can be given by MDI?
Fluticasone
Bronchodilator that can be administered once daily to cats?
Theophylline
Patients with obstructive disease have more difficulty with which phase of respiration?
expiration
A 6 year old, male castrated, domestic short hair cat is presented for respiratory distress. His respiratory rate is 65/min. He is breathing too quickly to discern which phase is most affected. On auscultation, expiratory wheezes are heard. He most likely has …
obstructive (small airway disease)
An 8 year old, spayed female, DSH cat is presented for respiratory distress. Her respiratory rate is 65/min. Neither phase of respiratory is obviously more effortful than the other. She has decreased lung sounds bilaterally. The only other remarkable finding is a body temperature of 104 F (40.0C). The most likely differential diagnosis is
Pyothorax
A 10 year old, male castrated, Labrador retriever is presented for respiratory distress. His respiratory rate is 35/min. Stridor is audible during inspiration. He most likely has…
Extrathoracic large airway obstruction
A 5 year old, male castrated Great Dane is presented for respiratory distress and stertor. He is cyanotic. His respiratory rate is 30/min. Inspiration is prolonged relative to expiration. He most likely has …
extrathoracic large airway obstruction
A Baermann can be used to identify _______ larvae in dogs, but this parasite has so far only been seen in the northeastern part of the country
Crenosoma
Lung specimen collection techniques that do not require general anesthesia
- trans-tracheal wash
- lung aspiration
Treatment for lung lobe torsion
Lobectomy
Treatment for cryptococcus
fluconazole
Sildenafil is indicated for _________
pulmonary hypertension
What is the appropriate treatment for ARDS?
positive pressure ventilation
Aspergillosis is treated with ____________
Topical Clotrimazole
Nasal mites-name
Pneumonyssoides caninum
An effusion with 1 g/dl protein and 300 cells/ul, most of which are mesothelial cells and neutrophils.
Transudate
An effusion with a total protein of 4.3 g/dl and 20,000 cells/ul, most of which are non-degenerative neutrophils.
exudate
An effusion with a total protein of 4.0 g/dl and 70,000 cells/ul, most of which are degenerative neutrophils, and intracellular bacteria
exudate
One cytologic characteristic used to identify a hemorrhagic effusion is the presence of
RBCs within macrophages
A 10 year old, spayed female, Siamese cat is presented for lethargy and tachypnea. Radiographs confirm pleural effusion. Cytology of the effusion: 5.0 g/dl protein; 15,000 cells/ul; primarily non-degenerative neutrophils and macrophages. On physical examination you notice chorioretinitis. Of the following choices, which is the most likely differential diagnosis.
FIP
Name four possible underlying causes of pulmonary edema
- overhydration
- LHF
- smoke inhalation
- electrocution
Name two possible underlying causes of PTE
- Hyperadrenocorticism
- IMHA
Treatment for nasal aspergillosis
Topical clotrimazole
Nasopharyngeal polyps can result in chronic nasal discharge, signs of upper airway obstruction, otitis externa, and ____________
Head tilt
Tx for uncomplicated acute tracheobronchitis
rest, time important
- abx prescribed sometimes (mycoplasma and bordetella involvement)
- Doxycycline (follow with liquid to avoid stricture)
- could do cough suppressant
Are asthma attacks common with canine chronic bronchitis?
NO
Normal protective mechanisms of the lung
- Physical protection of larynx, pharynx
- Mucociliary apparatus
- Cough
- Macrophages
- Inflammatory response
Components of the bellows mechanism
chest wall
diaphragm
pleural space
Open glottis injury
Diaphragmatic hernia
A tear in the lung parenchyma or tracheo-bronchial tree results in what type pf pneumothorax
closed
Clinical signs of pneumothorax
- resp distress
- chest wall expansion
- hollow percussion of thorax
- shock
- cyanosis
You can test for what antigens in urine?
Blasto, Histo
Antibiotics indicated if you suspect “kennel cough”
doxycycline or amoxicillin-clavulanate
Pure transudate
Low protein <2.5-3 g/dl
Low cells <500-1000/ul
What characteristic confirms septic exudate?
intracellular bacteria
Blastomycosis treatment
Fluconazole (Itraconazole) +/- Amphotericin B(reserved for worst cases)
- Fluconazole has better ocular penetration
Ddx for transudates
- RHF
- Pericardial dz
- neoplasia
- diaphragmatic hernia
- hypoalbuminemia (pure transudate)
Ddx for non-septic exudates
- FIP
- Lung lobe torsion
- Neoplasia
- Diaphragmantic hernia
Ddx for septic exudate
- pyothorax
- foreign body
- idiopathic
Ddx for chylous effusion
- idiopathic
- traumatic
- anterior mediastinal mass
- neoplasia
- heart dz
- heartworm
- pericardial disease
Most common complications of transthoracic lung aspiration
- pneumothorax
- hemothorax
- pulmonary hemorrhage
What type of sampling techniques are appropriate for diffuse interstitial disease?
lung aspirate or NB-BAL
