242 Diseases of the Pulmonary Parenchyma Flashcards
What is commonly associated with inspiratory, expiratory, or mixed effort?
- resp distress caused by pulmonary parenchymal disease results in mixed inspiratory and expiratory effort
- predominantly inspiratory effort observed with upper airway obstruction or pleural space disease
- expiratory effort observed in lower airway/bronchial disorders
What are common physical exam findings of animals with pulmonary disease?
- unremarkable, or marked systemic or thoracic disease
- weight loss, fever, lymphadenomegaly, and distal limb swelling from hypertrophic osteopathy
- RR & effort, cyanosis, increased or decreased bronchovesicular lung sound, +/- adventitial sounds on auscultation are suggestvie of airway, thoracic space, or pulmonary disease.
What are the benefits and drawbacks of evaluating oxygenation?
- useful for evaluating animals with suspected pulmonary parenchymal disease, but nonparenchymal disease can cause hypoxemia.
- cyanosis confirms hypoxemia, but is insensitive, subjective, and not useful in anemic animals.
- better tests of oxygenation include pulse oximetry and arterial blood gas analysis.
- blood gas analysis is useful for making decisions on supplemental oxygen or mechanical ventilation and to monitor response to therapy
- also calculating PaCO2 and alveolar-arterial gradients is used to determine mechanisms for hypoxemia.
What are the mechanisms of hypoxemia?
- hypoventilation
- ventilation: perfusion (V:Q) mismatch
- Right-to-left shunting (intrapulmonary or cardiac)
- Diffusion impairment
- reduced inspired oxygen partial pressure
What are examples of hypoventilation? how can it be recognised on blood gases?
- Drug induced respiratory depression
- CNS or peripheral nerve disorders
- Upper airway obstruction
Recognised:
- Increased PaCO2
- Normal (A-a) gradient
- Absent radiographic pulmonary infiltrates
What are examples of Ventilation:perfusion (V:Q) mismatch? how can it be recognised on blood gases?
- bacterial pneumonia
- pulmonary oedema
- pulmonary thromboembolism
Recognised:
- increased A-a gradient
- mildly increased PaCO2
- Improves with O2 supplementation (not TEM)
- pulmonary radiographic changes variable but common
What are examples of ‘Right - to -left shunting (intrapulmonary or cardiac)’? how can it be recognised on blood gases?
- right-to-left patent ductus arteriosus (cardiac)
- Pulmonary arteriovenous fistulae with marked pulmonary hypertension
- Atelectatic lung (pulmonary)
- Pulmonary thromboembolism
Recognised:
- increased (A-a) gradient
- fails to improve with O2 supplementation
- cardiac or pulmonary radiographic changes common
What are examples of ‘Diffusion impairment’? how can it be recognised on blood gases?
- asbestos
- idiopathic pulmonary fibrosis
Recognised:
- marked interstitial radiographic infiltrates common
- improves with O2 supplementation
What are examples of ‘reduced inspired O2 partial pressure’? How can it be recognised on blood gases?
- high altitude
- Anaesthetic accident
- suffocation
Recognised:
- resolves with O2 supplementation
What are the implications of the following on CBC in pets with pulmonary disease?
- neutrophilia
- neutropenia
- Eosinophilia
- monocytosis
- thrombocytopenia
- Erythrocytosis
- neutrophilia = infectious pneumonia and inflammatory lung disease, including ARDS
- neutropenia = sepsis, ARDS
- Eosinophilia = hypersensitivity disorders, eosinophilic pneumonia, or parasitic disease
- Monocytosis = consider mycotic lung disease, histiocytic disease
- Thrombocytopenia= consider sepsis, pulmonary thromboembolism, vasculitis, pulmonry hemorrhage
- Erythrocytosis: chronic hypoxemia
What are the implications of the following on biochem in pets with pulmonary disease?
- hypoalbuminemia
- hypercholesterolemia
- hyperglobulinemia
- hypercalcemia
- increased ALT
- hypoalbuminemia = pulmonary thromboembolism resulting from PLN/PLE, systemic inflamm, and infectious disease with pulmonary manifestation
- hypercholesterolemia= pulmonary thromboembolism resulting from PLN
- hyperglobulinemia = infectious and inflamm disease
- hypercalcemia = neoplasia and granulomatous fungal disease
- increased ALT = supports hypoxemia
What are the implications of the following on urinalysis in pets with pulmonary disease?
- proteinuria
- bacteruria
proteinuria = pulmonary thromboembolism resulting from PLN, systemic inflamm disease
Bacteruria = consider sepsis
What are the differential diagnosis associated with alveolar infiltrate?
- pneumonia
- oedema (cardiogenic or noncardiogenic)
- hemorrhage/contusion
- primary lung neoplasia
- metastatic neoplasia
- atelectasis
- pulmonary thromboembolism
- drowning
- smoke inhalation
What are the differential diagnosis associated with Bronchiolar infiltrate?
- feline asthma
- chronic bronchitis
- eosinophilic bronchitis
- peribronchiolar cuffing (e.g. oedemma, inflammation)
- bronchial calcification
What are the differential diagnosis associated with interstitial patterns?
- Aging change (U)
- Pulmonary fibrosis (U)
- Lymphoma (U)
- Primary lung neoplasia (S>U)
- Pulmonary metastasis (S>U)
- Fungal pneumonia/granuloma (S>U)
- Eosinophilic pneumonia (S>U)
- Foreign body reaction (S>U)
- Hematoma (E)
- Abscess (S)
- Cyst (S)
e= either S= structured U = unstructured
What are the differential diagnosis associated with vascular patterns?
- Heartworm
- Thromboembolic disease
- Pulmonary hypertension
- Congestive heart failure