Pulmonary Diseases Flashcards
What is dyspenoa?
Difficulty or laboured breathing
What are 4 causes of dyspenoa?
Respiratory distress
Tachypnoea
Panting
Orthopnoea
Dyspnoea is triggered by …?
Hypoxaemia or hypercapnia
What is hypoxaemia and its causes
- Decreased fraction of inspired O2
- Hypoventilation
- Diffusion impairment
- Right-to-left cardiovascular shunt
- Ventilation-perfusion (VQ) inequality
- Abnormal haemoglobin
How should you approach a dyspnoeic patient?
- Remember that these patients are very fragile
- DO NOT STRESS
- Critical patient?
- Can be helpful to give these patients a mild sedation
- Decide if dyspnoea is due to cardiac or respiratory disease
What questions should be asked when gathering the history of a patient with dyspnoea?
- Does the animal have any history of pre-existing cardiac or respiratory disease?
- Is there any history of trauma or toxin ingestion?
- Has the animal been coughing or showing exercise intolerance?
- Is there a history of syncope or seizure?
- Has the animal been previously diagnosed with any other medical conditions?
- Has there been a change in bark?
- Has the animal been coughing or sneezing?
- Has the animal been vomiting?
How can the types of dyspnoea be differentiated using observation?
Obstructive
- Inspiratory: upper airway obstruction.
- Expiratory: bronchial narrowing
Restrictive
- Pulmonary
- Pleural
What are the 3 DDx of inspiratory dyspnoea?
- Laryngeal paralysis
- Laryngeal neoplasia
- Tracheal mass/stenosis
What are the 2 DDx of expiratory dyspnoea?
Dynamic airway collapse
Feline asthma
What are the DDx of mixed dyspnoea?
- Pulmonary parenchymal disease
- Pneumonia
- Pulmonary oedema
- Idiopathic pulmonary fibrosis
- Pleural effusion
- Pneumothorax
- Pulmonary thromboembolism
What would you assess on the clinical exam of a patient with dypnoea?
- MM colour
- Auscultate heart and lung field
- Assess thoracic compressibility (cats)
- Percussion
- Effect of body position on dyspnoea?
- Watch ribs from above (no movement in tension pneumothorax, any flail segments?)
- Normal respiration or paradoxical?
How would you stabilise a patient with dyspnoea?
- Ensuring a patent airway
- Oxygen supplementation
- Minimizing stress
- Establishing vascular access
- Initial blood testing
- Thoracic radiographs !!!!!!
- Drug therapy directed at the most likely aetiology of respiratory distress
How is oxygen therapy delivered to a dyspnoeic patient?
- Deliver oxygen without stress via cage / incubator (small patients), face mask, nasal catheter, Elizabethan collar & cling film etc.
- Aim for 30 – 50% inspired O2
- Avoid 100% oxygen for more than a short time (oxygen toxicity)
- Oxygen must be humidified
- Monitor response to oxygen
Which condition is associated with dramatic lung crackles on auscultation?
Idiopathic pulmonary fibrosis
Which laboratory diagnostic samples would you want to take from a dyspnoeic patient?
- Complete blood count
- Serum Biochemistries
- Urinalysis
- Serologic and other advanced testing
Name the 4 initial diagnostic tests you might carry out in the dyspnoeic patient
- Thoracocentesis
- Imaging
- Cardiac diagnostic tests
- Respiratory diagnostic tests
Inspiratory stridor is normally associated with …?
Upper airway obstruction
Pneumonia in small animals is normally associated with what condition?
Broncho-pneumonia
Aspiration pneumonia is associated with which 3 conditions?
Megaoesophagus
Laryngeal paralysis
After tie-back surgery
What does a ventral distribution of pneumonia in the lungs suggest?
Suggests airway disease or aspiration as initiating factor
Caudodorsal involvement of the lungs with pneumonia suggests?
Haematogenous spread
Name some bacterial causes of infectious respiratory disease
Bordetella bronchiseptica
Chlamydia felis
Mycoplasma
Streptococcus equi
Name some viral causes of infectious respiratory disease
Canine distemper virus
Canine adenovirus 2
Canine herpes virus
Canine parainfluenza virus 2
Canine respiratory coronavirus
Canine influenza
Feline calicivirus
How can a pleural effusion be detcted?
- Reduced percussion resonance ventrally
- Heart sounds may be muffled
- Breath sounds may be absent or reduced ventrally as well
How is a pleural effusion diagnosed when strongly suspected?
Thoracocentesis
7 –8th intercostal space while maintaining suction
A sample can be retained for cytology, bacteriology etc. as appropriate, but once confirmed, the pleural effusion should be completely drained.
Which antibiotics would you use for a mild bacterial pneumonia?
Doxycycline
Amoxicillin-clavulanic acid
How does aspiration pneumonia present on a radiograph?
Bronchioles can be clearly seen on x-ray
Alveoli are full of contents
Name the heartworm of dogs
Angiostrongylus vasorum
Where does Angiostrongylus vasorum reside in the body?
In pulmonary vessels
What are the clinical signs of Angiostrongylus vasorum?
Cough
Shortness of breath
Hypoxaemia
Exercise intolerance
Can also cause coagulopathies, neurological signs etc.
How is Angiostrongylus vasorum diagnosed?
Need index of suspicion – may be weird clinical signs!
Faecal Baermann’s to see larvae
Rectal swab, smeared onto slide, direct microscopy
Angio Detect (IDEXX) - snap test
How would an Angiostrongylus infection present on a radiograph?
Enlargement of pulmonary arteries, but typically, there is just a patchy, pulmonary infiltrate, which is predominantly peripheral in the lung field.
How is angiostrongylus treated?
Fenbendazole
Moxidectin
When is it appropriate to FNA a lung mass?
Only if the mass is NEXT to chest wall (or risk pneumothorax)
Can be ultrasound guided
Obtain samples for cytology
Where is the most frequently affected site of metastatic disease from a variety of neoplasms?
Lungs
Which breed is most commonly affected by idiopathic pulmonary fibrosis?
West highland white terrier
How do dogs with idiopathic pulmonary fibrosis present?
Severely dyspnoeic
Cyanotic
Marked abdominal effort
Palpable rectus abdominus muscle hypertrophy
Widespread inspiratory crackles
How is idiopathic pulmonary fibrosis treated?
- Symptomatic support: nothing proven to be effective
- General management: restrict exercise and excitement
- Dogs will cough, have exercise intolerance, collapse
- Bronchodilators? (especially if airway collapse or concurrent chronic bronchitis)
- Steroids (Prednisolone)?
- Anti-fibrotics (e.g. Colchicine)?
Which poisoning results in severe dyspnoea?
Paraquat Poisoning
Describe the effects of paraquat poisoning
- Herbicide
- Severe pneumotoxin
- Initial alveolitis progresses to severe pulmonary fibrosis
- Very poor / hopeless prognosis
Pulmonary thromboembolism usually occurs secondary to..?
Underlying systemic diseases e.g.
IMHA
Protein losing conditions
Hyperadrenocorticism
Pancreatitis
Sepsis
DIC
How might a pulmonary thromboembolism present?
- Normally, no adventitious respiratory sounds on lung auscultation. May be a loud S2 on cardiac auscultation (due to associated pulmonary hypertension; delayed closure of pulmonic valve).
- Radiographic findings may not be evident or are subtle
How is pulmonary thromboembolism diagnosis confirmed?
Blood gas analysis
How would you treat confirmed or suspected pulmonary thromboembolism?
- Oxygen supplementation (but large V/Q (=ventilation/perfusion) mismatch).
- Sedation / anxiolytics
- Treat underlying disease
- Anticoagulant treatment to prevent further episodes
ARDS stands for?
Acute respiratory distress syndrome
Pulmonary hypertension is linked to increases in which 3 factors?
Pulmonary blood flow
Pulmonary vascular resistance
Pulmonary venous pressure
What respiratory pattern do you expect to have in a cat with asthma?
Expiratory dyspnoea
What respiratory pattern do you expect to have in a dog with pneumonia?
Mixed inspiratory and expiratory dyspnoea
