Clinical examination and investigation of respiratory disease Flashcards Preview

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Flashcards in Clinical examination and investigation of respiratory disease Deck (46):
1

history + signalment

Herd or individual problem
Neonate, juvenile, or adult
Performance, pleasure, or production
Management and environment
Disease time course and features
Response to treatment

2

cough description

type (non/productive)
frequency

3

observe from a distance - what to look for

general behaviour and demeanour
Respiratory rate, effort and pattern
inspiratory and expiratory noise

4

general clinical exam

Body condition
Posture
Abdominal effort
Hypertrophy of abdominal muscles
Mucous membranes
Eyes
Jugular veins
Pectoral oedema

5

specific clinical exam

Nares and Nasal Passages
airflow obstruction
Discharges

6

paranasal sinuses - horse

Looking for facial symmetry
Percussion

7

pharyngeal area

Guttural Pouches (Horse) - swelling
Lymph nodes - enlargement, discharges
Larynx (Horse) - Asymmetry of cricoarytenoideus dorsalis muscle - Movement in response to slap over withers

8

Equine Thoracic Auscultation and Percussion

Quiet room
Just audible in adult horse
Louder in foals and thin animals
Absence of noise - consolidation
Radiating heart sounds with pleural effusion

9

Ruminant Auscultation and Percussion area

6th intercostal space - point of the elbow
9th intercostal space - midway
11th - level with the tuber coxae
diaphragmatic border - straight

10

Auscultation - Small Animals

Not a reliable indicator of respiratory disease
Absence of sounds does not imply absence of disease
Usually significant if respiratory noise increased
Beware of referred noise from the URT
Differentiate crackles and wheezes

11

Auscultation - Small Animals - Crackles

likely to indicate small airways and alveoli

12

Auscultation - Small Animals - Wheezes

partial obstruction of larger airways

13

Apex Beat (SA) - shifting

displacement of the heart - probably due to a space occupying lesion

14

Endoscopy - Equine

At rest – standing restrained animal +/- sedation
Exercise – treadmill or dynamic endoscopy
Techiques - Tracheal aspirate, BAL, Biopsy, FB retrieval

15

endoscopy - equine - what to see

Nasal passages
Guttural pouch
Nasopharynx
Soft palate
Larynx
Trachea

16

Endoscopy in Small Animals - what is accessible

Trachea
Mainstem bronchi
Larger divisions of main bronchi
Smaller airways not accessible

17

Endoscopy - Small Animals

Patient able to tolerate general anaesthesia
Sufficient diameter of trachea to accommodate the endoscope (> 5mm)
Take radiographs before endoscopy
Artefact following washes
Place patient in sternal recumbency
Examine airways in systematic fashion

18

endoscopy - small animals - most useful cases

Diseases of major airways - Bronchitis, Parasitic bronchitis
Dynamic disease of the upper airway - Tracheal + Bronchial collapse, Consider also fluoroscopy

19

endoscopy - small animals - weaknessess

Unable to visualise smaller airways - Asthma
Unable to visualise parenchymal lesions - Solitary lung masses, Diffuse alveolar disease

20

Techniques Possible via endoscope

Aspiration of samples - Tracheal wash, Guided bronchoalveolar lavage, Cytology brushes
Biopsy of discrete lesions
Retrieval of foreign bodies

21

viral infection diagnosis

Paired serology
Virus isolation from buffy coat
Virus isolation from nasopharyngeal swabs
Viral antigen detection by FAT or ELISA from nasopharyngeal swabs
PCR to identify RNA/DNA of specific viruses

22

how to obtain Samples for Cytology and/or Bacterial Culture

Nasopharyngeal swab
Guttural pouch lavage (horse)
Endoscopically guided tracheal aspirate
Transtracheal aspirate
Bronchoalveolar lavage
Pleural fluid
Lung biopsy

23

Nasopharyngeal Swab

bacterial culture of specific organisms that are not normal comensals of the pharynx
e.g. Streptococcus equi equi

24

Guttural Pouch Lavage: Equine

Endoscope within GP
Plastic tubing via biopsy port
Aspirate mucopurulent discharge
Lavage both pouches and re-aspirate fluid
GP has commensal organisms
Streptococcus equi - Culture, PCR

25

Endoscopically-Guided Tracheal Aspirate: Equine

Position endoscope at thoracic inlet
Advance catheter and insert 30 mls sterile (buffered) saline
Withdraw sample
Post-exercise?

26

Endoscopically-Guided Tracheal Aspirate: Small Animals

General anaesthesia
Go via ET tube - Not in cats, pull tube first
Blind wash
Use plastic tube via ET tube

27

Endoscopically-Guided Tracheal Aspirate - advantages

easy to perform
non-invasive
sample is representative of the whole lung

28

Endoscopically-Guided Tracheal Aspirate - disadvantages

sample is contaminated by pharygneal flora (horse)
sample can be contaminated by equipment
wide range in normal cell populations
cells poorly preserved

29

Transtracheal Aspirate (Horse) - method

Surgically prepare site in lower third of the
trachea
Local anaesthetic
Insert guide catheter (10 gauge, 3 inch) or needle between tracheal rings
Insert sample catheter (16-14 gauge, 30 cm)
Insert 25 - 30 mls sterile saline
Withdraw sample
Remove sample catheter
Remove guide catheter last to avoid contamination of subcutaneous tissues

30

Transtracheal Aspirate - advantages

no pharyngeal contamination
no specialised equipment
useful in young foals where standard endoscopes are too large

31

Transtracheal Aspirate - disadvantages

horse may cough catheter into pharynx and contaminate sample
invasive - cellulitis + subcutaneous emphysema

32

Trans-tracheal wash - Small Animals - Indications

Collection of tracheal secretions where endoscopy not available - Anaesthesia contra-indicated
Direct access to airway in conscious patient

33

Bronchoalveolar Lavage (Horse)

(Insert guide catheter into trachea)
Advance BAL tube into bronchus until it will not advance further
(Inflate balloon)
Insert 120 - 200 mls sterile saline
Withdraw sample

34

Bronchoalveolar Lavage (Horse) - advantages

sample obtained from the area of tract that is most likely to be affected by e.g. EIPH, COPD
narrow range of cell populations aids interpretation
equipment cheap and accessible therefore used in all large animal species

35

Bronchoalveolar Lavage (Horse) - disadvantages

site may not be appropriate in animals with localised pulmonary abscesses or pneumonias

36

Thoracocentesis: Equine

Select site in seventh or eight intercostal space, above lateral thoracic vein
surgical preparation and local anaesthesia
stab incision
blunt teat cannula or drain closed from atmosphere

37

Thoracocentesis: Small Animal

Cranial or caudal to heart
Site determined by radiography or ultrasound guidance
If fluid evenly distributed then rib-spaces 8 or 9 on either side
Use local anaesthesia (not in cat)
Closed system
catheter/needle, fluid extension set, Three way tap, large volume syringe

38

lung aspiration - indications

Where a discrete intrapulmonary abnormality exists or where there is diffuse disease that cannot be accessed in any other way an aspirate of the lung may be appropriate

39

lung aspiration

Use ultrasound or fluoroscopic guidance
Incr morbidity + mortality of unguided aspirates means these are saved for the most seriously ill patients

40

lung biopsy - advantages

not frequently performed
used for identification of specific forms of pathology
e.g. interstitial pneumonia, neoplasia

41

lung biopsy - disadvantages

very invasive - Thoracotomy/thoracoscopy
painful
complications include - uncontrollable haemorrhage, pneumothorax

42

faecal exam - small animals

Parasite larvae - Angiostrongylus vasorum

43

Thoracic Radiography

pulmonary
pleural cavity
mediastinum

44

Computed Tomography (CT) - small animals

Useful for pleural, mediastinal + parenchymal
structures.
High image quality of detailed sectional anatomical structure.
Cheaper and quicker and better detail of lung tissue than MRI
Does not require gating for respiration like MRI.
Radiation exposure unlikely to be an issue in our patients.

45

Thoracic Ultrasonography

Sound does not penetrate normal aerated lung
Sound will penetrate non-aerated (diseased) lung
Lesions that do not extend to the surface of the lung are not visible
Extremely useful for characterising pleural effusion
Can be used to obtain samples - pleurocentesis, lung biopsy etc.

46

pulomary function tests - equine

Track exercise tests
Treadmill exercise tests
Oesophageal manometry
Flow-volume loops
Oxygen uptake
Blood gas analysis