Week 1 - Parenchymal and interstitial disease Flashcards
Out of the following, which one presents with the worse clinical signs?
- URT obstruction
- Loss of thoracic capacity
- Disease of airway, parenchyma, interstitial
- Non CRS conditions
- URT obstruction
Higher up the obstruction = worse clinical signs
e.g
Blockage of on bronchi = one lung still working
Blockage of trachea = obstruction to the whole lung = bigger decrease in gas exchange = cyanotic
What are the main clinical signs of lung disease (parenchyma and interstitial)?
- Inspiratory/expiratory efforts?
- Cough??
- Cyanosis?
- Respiratory depression?
- Noise?
- Increased inspiratory and expiratory effort (but inspiratory effort predominates)
- Cough may/may not be present
- Cyanosis less common
- Minimal respiratory depression (only in severe cases)
Noise:
- Crackles or wheezes
- Increased/decreased bronchovesicular sounds
Patients with lung disease (parenchyma and interstitial) are fragile, what often needs to be done ASAP?
Oxygenate
Emergency ultrasound
- Determine whether the pleural space is involved
Pleural space = decreased lung sound
What are the 6 most common lung diseases in small animals?
Aspiration pneumonia
Pulmonary oedema
Drowning
Canine/feline inflammatory airway disease
Eosinophilic lung disease
IPF (idiopathic pulmonary fibrosis)
What is aspiration pneumonia and what is the outcome based on?
Inhalation of material into the lower airway.
Material = stomach contents - Acidic and causes damage to stomach.
Outcome:
- pH
- Bacterial contents
- Volume
- Particle size
What are the signs of aspiration pneumonia and how is it diagnosed?
Signs:
- Cough
- Harsh/reduced lung sounds
- Tachypneoa
- Pyrexia
Diagnosis:
- Radiograph (alveolar filtrate patchy/focal, lung lobes: right middle, right cranial, left cranial)
- BAL CONFIRMS
What is the treatment for aspiration pneumonia?
Supportive
- Oxygen
- Antibiotics
Treat underlying cause
Anti-acid medication if frequent reoccurrence
Metoclopramide to improve motility and increase lower oesophageal sphincter tone.
What lung pattern is seen with aspiration pneumonia?
Alveolar
- Bronchograms visible
- Alveoli have soft tissue opacity as fluid present
What is pulmonary oedema?
Fluid accumulation in the intersitium and subsequently the alveoli at a rare that exceeds removal.
Leads to respiratory compromise are termed acute lung
injury (ALI) or acute respiratory distress syndrome (ARDS)
What causes pulmonary oedema?
Consequence of various conditions
▪ Increased hydrostatic pressure
▪ Reduced oncotic pressure
▪ Increased vascular permeability
▪ Impaired lymphatic drainage
Pulmonary oedema can be cardiogenic or non cardiogenic, what are the mechanisms behind them?
CARDIOGENIC
- Increased hydrostatic pressure = forces fluid out of the capillaries and into the surrounding lung tissue
- Causes low protein as vascular permeability remains unchanged= low oncotinc pressure less force pulling fluid back into the blood vessels, making it easier for fluid to leak out into the lung tissue.
- More responsive to treatment as can dress the hydrostatic pressure
NON-CARDIOGENIC
- Driven by lung damage
- Lung damage increases vascular permeability.
- High-protein fluid enters lung tissue.
- Raised pressure disrupts blood flow and ventilation.
- Fluid causes stiff lungs, airway compression, and higher resistance.
- Fluid is cleared by sodium/chloride transport.
- Damaged epithelium prevents fluid removal.
- Harder to treat than cardiogenic oedema as cannot address epithelial damage
What is the most common cause of pulmonary oedema?
Pulmonary epithelial injury
(Non cardiogenic, damage to the lung)
What are the signs of pulmonary oedema and how is it diagnosed?
Signs:
- Delayed onset (damage -> signs 72hrs later)
- Moist cough (produce froth)
- Orthnopnea
- Cyanosis
- Harsh bronchovascualr lung sounds
- Crackles
Diagnosis:
- Radiograph = unstructured interstitial pattern ‘mist’ that can progress to alveolar (bronchograms and soft tissue opacity).
How is pulmonary oedema treated?
Address underlying cause, treat ARDS/ALI
Oxygen supplementation
+/- Sedation
Support – keep affected lung dependent
Diuretics less effective for non-cardiogenic oedema but still indicated
What causes physical lung injury, how is it diagnosed and treated?
CAUSE:
Thoracic trauma
- Chest wall damage and pain
- Increased reps rate (animal count be in RTA with a broken leg, make sure increase resp is not thoracic damage and not just pain).
DIAGNOSIS
Thoracic radiograph
- Lag phase between clinical findings and radiograph changes
TREATMENT
- Supportive care - oxygen
- Stabilisation of thoracic wall
