Week 1 - Lung and Airway Diagnostics Flashcards
What diagnostic tests are available in a coughing dog?
Rank them as that diagnoses the most things to the least things.
- Imaging (CT/Radiography)
- Endoscopy
- Bronchoalveolar lavage (BAL)
- Trans-tracheal wash (TTW)
- Haematology/Biochemistry
- Faecal (parasites only)
What are the indications for a tracheal wash?
Main indication - suspect a large airway disease (tracheobronchial tree up to the level of segmental bronchi).
Can also provide information about small airways (bronchioles and acartilagenous airways).
Cough reflex retained.
Patients that cannot be anaesthetised (too compromised to be induced for a BAL) as can be carried out on a conscious patient.
What is the difference between a trans-tracheal wash (TTW) and a endotracheal wash (ETW)?
TTW = smaller patients than a tube can be passed through a sterile endotracheal tube.
ETW = Needle needs to be passed directly into the trachea.
Which test is more sensitive, tracheal wash or bronchoalveolar lavage?
Bronchoalveolar lavage
As a tracheal wash can be done on a conscious patient, how is the area prepared?
- Clip and surgically prep the area
- Inject local over the site between tracheal rings
- Nick skin with scalpel to facilitate passage of catheter
What are the indications for a bronchoscopy?
Investigate unexplained clinical signs.
To obtain diagnostic samples.
Evaluate radiographic lung lesions.
Assessment of airways.
Treatment of airway disease.
What are the benefits of bronchoscopy?
Relatively safe procedure
Diagnostic for a number of conditions.
Allows collection of samples.
Allow removal of foreign material
What are the contraindications for a bronchoscopy?
Take care with hyper-responsive airways:
- Cats with allergic bronchial disease
- Dogs with wheezing suggesting airway spasm
Unstable cardiac failure/arrhythmias
Tracheal obstructions
Haemorrhage…increased risk with:
- Pulmonary hypertension
- Uraemia
- Coagulopathies
- Neoplasia/gross lesions
How is bronchoscopy performed?
- Sterile
- Under GA to prevent scope damage (scope type: video better than fibreoptic). Note airway vs scope diameter is important
- Sternal recumbancy
- Elevate head so note is parallel to the table
- Lubricate scope as necessary (sterile lube required).
What equipment is needed for bronchoscopy?
- Sterile large ET tube
- Y connector/T connector
- Adapter self sealing port
- Sterile lube
- Urinary catheter
Can an ET tube be always used for bronchoscopy?
No - small cats and dogs cannot use an ET tube as they are too small to pass the endoscope down.
How are the patients monitored?
With pulse oximetry/end tidal capnography
How is the endoscope passed down in bronchoscopy?
Directly through the larynx - TAKE EXTREME CARE!
What equipment is used for pre-oxygenation and for how long in bronchoscopy?
Urinary catheter is used to delivery oxygen.
Pre-oxygenation 30-45 seconds
What is the order of the structures assessed in bronchoscopy?
Larynx, pharynx, trachea
Right principle bronchus
- Right cranial lung lobe
- Right middle lung lobe
- Right accessory lung lobe
- Right caudal lung lobe
Left principle bronchus
- Left cranial lung lobe (2 branches, cranial and caudal)
- Left caudal lung lobe