Respiratory: Pulmonary Diseases

Question 1

What does severe pulmonary disease frequently result in?

Answer 1

Dyspnoea

Question 2

What happens when pulmonary parenchymal diseases result in a ventilation: perfusion mismatch?

Answer 2

Can be identified by arterial blood gas analysis
If PaO2 falls below 60mmHg the patient will be clearly cyanotic and emergency treatment required

Question 3

If the animal is making an audible breathing noise (without a stethoscope) what is it associated with?

Answer 3

Associated with upper respiratory tract disease

Stertor, stridor

Question 4

What may expiratory dyspnoea be associated with?

Answer 4

May be associated with dynamic airway collapse or bronchial narrowing
Expiration may be slow and associated with marked abdominal effort

Question 5

What dyspnoea can pulmonary oedema and idiopathic pulmonary fibrosis result in?

Answer 5

May result in both inspiratory and expiratory dyspnoea and increased RR, respiratory depth is shallow.

Pleural effusions, pneumothorax also result in combined dyspnoea

Question 6

What is the difference between an obstructive dyspnoea and restrictive?

Answer 6

Obstructive- increased effort
Restrictive- fast, shallow respirations

Question 7

What can cause obstructive dyspnoea?

Answer 7

Can be inspiratory, due to upper airway obstruction (BOAS, laryngeal paralysis- normally upper resp noise)
Or expiratory due to bronchospasm- feline asthma

Question 8

What does restrictive dyspnoea cause?

Answer 8

Is normally both inspiratory/expiratory dyspnoea
Can be due to pulmonary parenchymal disease or pleural effusions/pneumothroax

Question 9

What is the initial treatment for a dyspnoeic animal?

Answer 9

Provide humidified oxyen (try and maintain <50% inspired O2)
100% should be avoided for all but can be given for a short time to avoid oxygen toxicity

Question 10

How can oxygen be provided for a dysponeic animal?

Answer 10

• In an incubator
• In a temporary oxygen cage
• Into an elizabethan collar with cling film
• Via intranasal oxygen catheter
• Via a face mask

Patients reciveing O2 in a chamber can overheat rapidly

Question 11

What can a poor response to oxygen in a dyspnoeic, cyanotic animal reflect?

Answer 11

More likely to suggest a congenital heart disease with right to left shunting
Pulmonary oedema or respiratory causes of dyspnoea should respond to O2 supplementation

Question 12

As well as recording respiratory rate what else should be recorded?

Answer 12

Pattern of respiration

Question 13

What is a normal respiration pattern?

Answer 13

Inspiration 30%
Expiration 60%
Pause 10%

Question 14

What may an increased duration and effort of inspiration show?

Answer 14

Consistent with upper airway obstruction or pulmonary parenchymal lesions

Question 15

What can increased depth of respiration be associated with?

Answer 15

Mass lesions or diaphragmatic rupture

Question 16

What can rapid shallow respirations be associated with?

Answer 16

Pulmonary parenchymal disease- pulmonary oedema, idiopathic pulmonary fibrosis

Question 17

What is paradoxical respiration?

Answer 17

Part of the ribs being ‘sucked in’ during inspiration

Question 18

What can paradoxical respiration be associated with?

Answer 18

• May result from a flail chest (rib fractures, post trauma)
• Certain neurological lesions
• Any dyspnoeic animal (especially pleural disease)

Question 19

On a cursory clinical examination of dyspnoeic dog, what can show heart failure rather then respiratory disease?

Answer 19

Dogs with heart failure usually have tachycardia or arrhythmias and heart murmurs or diastolic gallops

Question 20

What clinical signs can show significant respiratory disease and cardiac disease to be less likely?

Answer 20

Presence of sinus arrythmia- may show increased vagal tone

Question 21

1. What disease is associated with dramatic crackles ‘cellophane’?
2. What disease results in soft, inspiratory crackles

Answer 21

1. Idiopathic pulmonary fibrosis
2. Pulmonary oedema

Question 22

What are expiratory wheezes usually associated with?

Answer 22

Bronchial narrowing

Question 23

How can you ‘unmask’ respiratory sounds?

Answer 23

Sometimes adventitious respiratory sound can be unmasked by precipitating a paroxysm of coughing
After attempting to elicit a cough by tracheal pinch, the lung field should be re-auscultated

Question 24

What is inspiratory stridor normally associated with?

Answer 24

Upper airway obstruction

Question 25

On a cursory clinical exam what should be checked and asked?

Answer 25

* Ascultate lungs, elicit cough * Trachea and larynx- collapse/paralysis * Ask about bark/miaow- change laryngeal disease * Percussion resonance- pleural effusions or masses * Assessing thoracic compressability in cats (cranial thorax)- less with anterior mediastinal masses or pleural effusion * Careful attention to position of the heart * In diaphragmatic rupture with significant herniation of the abdominal contents into the thoracic cavity, improvements may be seen by holding the animal up by its front legs

Question 26

How can pleural effusion be detected?

Answer 26

Often by reduced percussion resonance ventrally Or by T-FAST ultrasound scan

Question 27

Describe the process of thoracocentesis for a pleural effusion

Answer 27

* 21G 1 inch butterfly catheter * Introduced cautiosly about the 7-8th intercostal space while maintaining suction * Via a three wat tap with a syringe * Sample can be retained for cytology/bacteriology * Once confirmed the pleural effusion should be completely drained

Question 28

What can the distribution of lesions radiographically suggest in bronchopneumonia/pneumonia?

Answer 28

Source of infection * Ventral distribution suggests it may be secondary to airway disease or aspiration * Caudodorsal distribution may indicate haematogenous spread * Aspiration pnemonia secondary to megaoesophagus

Question 29

What is pneumocystis carinii infection? How is it diagnosed and treated?

Answer 29

Rare cause of pneumonia in an immunosuppressed individual Dx- based on signalment, demonstration of the organisms on lung aspirated, immunoglobulins can support Treatment- trimethroprine potentiated sulphonamides | Some breeds of dogs- young dogs, CKCS

Question 30

What is the name of the french heart worm? What clinical signs may dogs have?

Answer 30

Angiostrongylus vasorum Dogs may be completely asymptomatic, typically cough or show respiratory signs May also show coagulopathy, ocular or neurological manifestations

Question 31

How can angiostrongylus vasorum infestations be diagnosed?

Answer 31

* Thoracic radiographs can show enlargment of pulmonary arteries * Dx- identification of larvae in faeces or BALF, angio detect SNAP test Occasionally causes pulmonary hypertension or atriovenous shunts bypass lung tissue- hypoxia, pulmonary thromboembolism

Question 32

How is angiostrongylus treated?

Answer 32

* Fenbendazole- 50mg/kg SID 7-21 days, then possibly repeat * Milbemycin oxime * Moxidectin- topical single treatment, repeat after 30 days

Question 33

What drugs can be used to prevent angiostrongylus infestations?

Answer 33

Moxidectin Milbemycin

Question 34

How are lung neoplasia usually ascertained?

Answer 34

Thoracic radiographs- all views allow attempt to localise Conformation requires obtaining tissue- FNA Most frequently affected site of metastatic disease

Question 35

1. What breed most commonly is affected by idiopathic pulmonary fibrosis? 2. How do dogs present? 3. How does it appear radiographically? 4. How can dogs be treated?

Answer 35

1. Mainly terrier breeds- highland white, cairn terriers 2. Severly dyspnoeic at presentation and cyanotic, marked abdominal effort, palpable rectus abdominus muscle hypertrophy 3. Generalised increase in interstitial markings may be present 4. Treatment non-specific- rested and unstressed, O2, bronchiodilators for airway collapse, steroids and colchicine anti-fibrotic Prognosis very guarded- survival usually only a few weeks

Question 36

What happens with paraquat intoxication?

Answer 36

Pneumotoxicity Severe dysponea, minimal radiographic change initially Later increased interstitial markings- prognosis hopeless, euthanised

Question 37

What does pulmonary thrombo-embolism result in?

Answer 37

Severe ventrilation: perfusion mismatch Ventilated areas of lungs recieve no blood flow PTE usually results from systemic conditions such as IMHA, DIC

Question 38

What can cause pulmonary thrombo-embolism?

Answer 38

* IMHA * Hyperadrenocorticism * Nephrotic syndrome * Sepsis * Pancreatitis * Neoplasia * DIC * Dirofilariasis

Question 39

How can PTE be confirmed? | pulmonary thromboembolism

Answer 39

Evidence of pulmonaty hypertension Doppler echocardiograhpy Very large thrombi can be visualised on echocardiography Arterial blood gas analysis

Question 40

How is PTE treated?

Answer 40

* Oxygen support * Sedation or anxiolytic * Anticoagulant therapy- low molecular weight heparin * Antiplatelet- low dose asprin, clopidogrel * Treat the underlying disease

Question 41

How can PTE be prevented?

Answer 41

In conditions where PTE is a significant risk- nephrotic synsdrome Low doses of aspirin or clopidogreal

Question 42

What can cause non-cardiogenic pulmonary oedema?

Answer 42

Electrocution Upper airway obstruction CNS disease Vasculitis

Question 43

What is ARDS?

Answer 43

Acute respiratory distress syndrome

Question 44

What is ARDS?

Answer 44

non-cardiogenic pulmonary oedema- secondary to range of respiratory or systemic insults Resp disease, oxygen toxicity, truama, electrocution, near drowning

Question 45

How is ARDS treated?

Answer 45

* Emergency stabilisation of the patient, sedation * Oxygen therapy * Bronchodilation * If not improving GA and IPPV * Furosemide only miminally effective * Fluid therapy for shocked patients * Hypoproteinaemic require colloids or plasma to improve oncotic pressure * Underlying disease treated aggresively

Question 46

What dyspnoea can pulmonary oedema and idiopathic pulmonary fibrosis result in?

Answer 46

May result in both inspiratory and expiratory dyspnoea and increased RR, respiratory depth is shallow. | Pleural effusions, pneumothorax also result in combined dyspnoea