LRT Wrap-Up Flashcards
What is the classic respiratory pattern in cats with pleural effusion?
- Often when cats have pleural effusion the inspiratory and expiratory phases are roughly equal.
- They look like bellows – the chest goes in, abdo out and vice versa
What is the classic respiratory pattern in animals with URT signs?
Animals with URT obstruction often have obvious inspiratory dyspnoea; inspiration will be much longer than expiration.
What is the classic respiratory pattern in animals with lung disease?
With lung disease, especially horses with COPD, the expiratory phase is much longer. The abdomen lifts as they force air out of their lungs. Lung disease therefore tends to produce an expiratory dyspnoea.
How does the clarity of the heart and lung sounds on ascultation make you more or less suspicious of certain diseases?
If the heart and lung sounds are muffled we are suspicious of pleural space disease (fluid obscuring the sound), if they are clear then it is more likely lung disease (fluid is inside the lungs rather than out).
Why is anaesthetising a patient with pleural effusion generally safe?
- In a cat with pleural effusion, it is safe to anaesthetise as you know draining the pleura will make the animal breathe better immediately and so it will be much more stable when you recover it.
- Pleural effusion is quite a typical presentation in a cat (breathing phases the same duration, look like bellows) so you are generally sure of what it is before anaesthetising.
What should you make sure you do with a pulmonary disease patient who is already anaesthetised for radiography, and why?
- In lung disease cases you may want to GA, radiograph/CT but also make sure you do a BAL while the animal is still asleep so that you have all the information you need from this anaesthetic.
- Don’t just wake it up without doing a BAL as you will not be much further forwards in working out the cause once they wake.
What are the major causes of dyspnoea?
- Airway obstruction
- Reduced airway capacity (pleural space disease)
- Pulmonary parenchymal disease
- Other – metabolic/physiologic causes
How do other causes of dyspnoea such as metabolic/physiologic causes differ from URT, pulmonary or pleural causes?
Tend to have rapid shallow breathing rather than genuine respiratory difficulty as in respiratory tract causes
What are the major clinical signs of airway obstruction?
often +/- cough/cyanosis/noise
What are the possible causes of airway obstruction? Indicate which causes are common?
- Trauma/haemorrhage etc
- Laryngeal paralysis/trauma/granuloma
- Brachycephalic airway obstruction- long soft palate, stenotic nares, larynx collapse etc
- Tracheal or bronchial collapse
- Extra-luminal mass lesions - thyroid, abscess, lymphoma, large heart
- Asthma/bronchospasm (cat)
- Nasopharyngeal polyp (cat)
- Nasal cavity (+/- sneezing, +/- nasal discharge) - rhinitis/F.B./neop/polyp/trauma
- F.B.
- Neoplasia
- Oslerus infestation - “lungworm”
- Brochiectasis
What are the possible causes of loss of thoracic capacity?
- Pleural effusion – e.g. pyothorax, haemothorax
- Pneumothorax
- Neoplasia - pleural or mediastinal
- Ruptured diaphragm
- Abdominal abnormality causing diaphragmatic compression – severe ascites, abdominal mass
- Gross cardiomegaly
What are the possible causes of loss of pulmonary parenchymal disease? Indicate which ones are common.
- Pulmonary oedema - L. heart failure typically
- Eosinophilic disease - “P.I.E or EBPn”
- Pulmonary fibrosis
- Pulmonary thromboembolism
- Non-cardiogenic pulmonary oedema
- Often following trauma and near-drowning
- Neoplasia - primary or (more likely) secondary
- Pulmonary haemorrhage
- Bronchopneumonia
- Paraquat poisoning
- Angiostrongylus/Aelurostrongylus
What are the possible ‘other’ causes of dyspnoea, i.e. metabolic/physiological?
- Hyperthermia/heat stroke/fever
- Obesity
- Excitement/fear/stress/pain/shock
- Parturition/false pregnancy/eclampsia
- Anaemia/abnormal haemoglobin/hypoxic toxins
- Metabolic disease – acid base disturbance
- CNS disease
- Endocrinopathy e.g. hyperadrenocorticism, GC therapy, hyperthyroidism
- Neuromuscular disease – eg myasthenia gravis
Plain lateral thoracic radiograph from a dog, coughing and unwell for 2 or 3 days:
Which of the following lung patterns is evident?
- Interstitial
- Alveolar
- Vascular
- Bronchial
- Mixed
Alveolar pattern
You have been presented with a 10 year old West Highland White Terrier that has been seen on numerous occasions over the past year with a cough and exercise intolerance. The owners have reported that despite various treatments the condition seems to be steadily progressing. You notice mild cyanosis of the mucus membranes and diffuse crackles over both hemithoraces.
Which of the following is the most likely differential diagnosis?
- Eosinophilic bronchopneumopathy
- Idiopathic pulmonary fibrosis
- Pyothorax
- Angiostrongylus vasorum infection
- Left-sided congestive cardiac failure
Idiopathic pulmonary fibrosis
