Respiratory introduction Flashcards
1
Q
Define the following:
Hypoxia
Hypoxemia
Hypercapnia
A
- Hypoxia = oxygen levels in the blood, lungs, and/or tissues is low
- Hypoxemia = insufficient oxygenation of the blood
- Resp. stimulant when PaO2 < 50mmHg (normal = 90-110mmHg)
- Hypercapnia = inc. CO2 levels, resp. stimulant
- Most powerful
2
Q
Cyanosis
What is it?
What’s normal?
When will it occur?
A
- Bluish to red-purple color in the tissues due to increased amounts of deoxygenated or reduced hemoglobin
- Animal w/ normal hematocrit
- Needs an arterial SaO2 73 and 78% pulse ox (PaO2 39-42mmHg) before cyanosis is found
3
Q
Dyspnea
Definition
What should you avoid?
What should you give to the animal?
A
- Difficult or labored breathing
- Avoid excessive stress or struggling, and avoid dorsal recumbency for rads
- Give animal additional oxygen immediately
4
Q
Define the following:
Stridor
Stertor
Orthopnea
A
- Stridor = high pitched inspiratory noise, rapid flow of air passed a rigid obstruction or paralysed/collapsed larynx
- Stertor = low-pitched inspiratory noise, gurgling or snoring sound, produced as air passes soft tissue obstruction
- Normal in brachycephalic dogs
- Orthopnea–adopt a strange position
- Sternal recumbency w/ elbows abducted, the neck extended and open-mouth breathing
5
Q
Respiratory disease
Diagnostic approach (steps)
4 disorders
A
- Diagnostic approach
- History/clinical signs
- PE/localization of disease
- Diagnostics/procedures
- Common drugs used in therapy
- Disorders
- Nasal disorders
- Airways–laryngeal, tracheal, bronchial disorders
- Pulmonary parenchymal diseases
- Pleural space diseases
6
Q
Respiratory diseases
What is included in the history (diagnostic approach)?
A
- What is the signalment
- Ciliary dyskinesia–generally younger
- Neoplastic–generally older
- Breed
- Brachycephalic–stertor
- Mesocephalic
- Dolichocephalic–obstructions, fungal inf.
- How long has it been going on for?
- Acute signs
- Progressive
- Chronic
- Acute signs
- Where is the location
7
Q
Differentiate between clinical signs of upper and lower respiratory diseases
A
- Upper = nares to larynx
- Lower = larynx to lungs
8
Q
What should you look for during the physical exam?
A
- What can you see
- Look for nasal discharge/disease
- Is there respiratory distress
- What can you hear
- Sneezing
- Breathing louder than normal
- Evidence of a cough
- What can be heard on auscultation
- What can you feel/touch
- What can you palpate
9
Q
Nasal disease
Signalment
A
Age, breed
10
Q
Nasal disease: physical exam
Airflow
Facial palpation
A
- Bilateral airflow?
- Glass slide technique, wisp of cotton wool
- Facial palpation
- Pain?
- Symmetry vs. asymmetry?
- Normal ocular retropulsion?
- Place thumbs over eyelids and gently press backwards, upwards, medially, laterally (checks for masses)
11
Q
Nasal disease: physical exam
Oral exam
Nasal discharge
A
- Oral exam
- Check dentition and dental arcade
- Check hard palate for abnormalities
- Check soft palate to see that it can be easily pressed upwards (anesthetized)
- Nasal discharge
- Characterize discharge:
- Serous (clear), mucoid (not clear), mucopurulent (cloudy), purulent (white/yellow), hemorrhagic (bloody)
- Unilateral vs. bilateral (doesn’t really matter when hemorrhagic)
- Persistent vs. intemittent
- Duration, has it changed over time
- Acute nasal disease often accompanied w/ sneezing
- Chronic nasal disease often has purulent to hemorrhagic discharge
- Characterize discharge:
12
Q
Nasal disease: physical exam
Sneezing
A
- Localizes disease to nasal cavity
- Protective mech. of upper airways
- May have concurrent nasal discharge
- Normal sneezing: expiratory, forceful
- Occasional, intermittent, persistent, paroxysmal
- Reverse sneezing
- Inspiratory
- Duration?
13
Q
Physical exam
Breathing sounds
A
- Stertor (low pitch, snoring)
- Brachycephalic airway syndrome
- Stridor
- Laryngeal paralysis
- Tracheal collapse
- Nasopharyngeal stenosis
14
Q
Physical exam
Cough–hallmark of?
A
- Hallmark of a tracheal or pulmonary disease (lower airways) or cardiac failure
- Use the signalment, history, clinical finding and rads to be able to distinguish between these causes
- Forceful expiratory effort/protective reflex
15
Q
Physical exam
Cough–triggers? Classification?
A
- Triggers include:
- Irritant receptors that lie between epithelial cells lining the airways (cough receptors)
- Inflammatory products of neutrophils or eosinophils
- Excessive secretions
- Airway compression or collapse
- Classified as
- Dry/non-productive
- Moist/productive
- Harsh/intermittent or paroxysmal (once it starts, gets progressively worse)
16
Q
Beautiful massive chart of cardiogenic vs. non-cardiogenic coughing?
A
17
Q
Respiratory distress terms
Panting
Respiratory distress
A
- Panting
- Dissipates heat–can be normal in dogs
- Cats: assoc. w/ stress or resp distress
- Resp distress
- Most frequently assoc. w/ lower airway disease
- Dogs w/ bilateral laryngeal paralysis (upper airways) are also in distress
18
Q
Respiratory distress (dyspnea)
Cause?
A
- Insufficient oxygen in inspired air
- Insufficient ventilation
- Insufficient circulation
- Insufficient erythrocytes
- Abnormal or low hemoglobin concentrations
19
Q
Hypoxemia
A
- Insufficient oxygen can result in cyanosis
- Color of mucous membranes
- Causes
- Lack of O2–upper/lower resp disease
- Abnormal hemoglobin–toxins
- Cardiac dz
- Pulmonary dz
- Cardiopulmonary arrest
20
Q
Respiratory patterns
Inc. inspiratory effort
Inc. expiratory effort
Shallow breaths and tachypnea
A
- Inspiratory
- Usually upper resp dz
- Expiratory
- Usually lower resp dz
- Shallow/tachypnea
- Indicates restrictive resp pattern
- Pulmonary/pleural/mediastinal dz
- Often orthopneic posture
- Discordant motion of chest and abdominal muscles–> suspect flail chest or resp muscle fatigue
- Indicates restrictive resp pattern
21
Q
Pulmonary sounds
Normal lung sounds
A
- Normal lung sounds are bronchovesicular
- Bronchial–loudest over hilus during expiration
- Mvt of air through tracheal bifurcation region
- Vesicular–loudest on inspiration at periphery of lungs, normal air filling lungs “rustling of leaves” (very soft sounds)
- Normal lungs will have normal bronchovesicular sound, but w/ disease you can have harsh or increased bronchovesicular sound
22
Q
Pulmonary auscultation (various sounds)
A
- Parynchymal disease–adventitial sounds
- Crackles–snapping open of airways that have closed due to fluid in/around them (rice krispies)
- Wheezes–caused by airflow through narrow opening–airways are constricted/narrowed
- Snaps–loud snaps over hilus at end of expiration indicates collapse of the intrathoracic trachea, carina, or mainstem bronchi
- Goose honks–sound w/ tracheal collapse
- Pleural friction rubs–creaking/grating sound due to roughened pleural surfaces rubbing against each other
23
Q
Pulmonary auscultation
Pleural disease
A
- Pleural effusion
- Lung sounds auscultated dorsally
- Lungs floating in fluid
- Muffled sounds ventrally
- Heart sounds also reduced
- Lung sounds auscultated dorsally
- Pneumothorax
- Abscence of lung sounds dorsally due to compression
- Only present in ventral field
- Both are emergencies–need to aspirate ASAP
24
Q
Pulmonary percussion: distinguish between air and fluid density
A
- Use your finger/small mallot to strike chest cavity and listen to the sound
- Fluid gives dull sound
- Pneumothorax will give inc. resonance
- Difficult in small dogs and cats
25
Minimum data base
* Remember: **stabilize patient before doing any tests**
* Cats often will need a couple of hours in oxygen chamber before any additional tests are done
* CBC, biochem, fecal, HW check (if required)
* Thoracic rads required in most situations (stabilize first)
26
T/F: X-rays are usually helpful in nasal disease cases
FALSE--x-rays are not sensitive at all with nasal diseases
27
**Rhinoscopy**
Performed when?
Otoscope vs. endoscope
Endoscopy steps?
* Performed after imaging
* Otoscope--limitations of depth, visibility, biopsy
* Endoscope--rigid or flexible; video-endoscope ideal
1. GA, cuff endotrach tube
2. Often perform pharyngoscopy at this stage to assess nasopharynx
3. Block off oropharynx w/ swabs
4. Enter each nare--examine dorsal, middle, ventral, and common meatus
5. Biopsy abnormal or normal areas if required
28
**Rhinoscopy**
Blind biopsies
**Do not pass medial canthus of eye (will go into brain--\> bad news bears)**
29
**Bronchoscopy**
Evaluation of what?
* Evaluates the larynx, trachea, and bronchi
* Evidence of tracheal collapse, foreign body, or neoplasm?
* Look at tracheal bifurcations and at the dif. bronchi
* Samples taken for cytology, culture and sensitivity and sometimes a fine needle aspirate or a biopsy is taken
* **Contraindicated in patients w/ severe respiratory distress (procedure requires general anesthesia)**
30
What is included in the extended data base (9)?
* Nasal flush
* Cytobrush
* Transtracheal aspirate
* Bronchoalveolar lavage
* FNA of lung
* Serology and/or PCR
* Cytology
* Biopsy
* Culture and sensitivity
31
**Nasal flush**
Indications?
Procedure?
* Indications
* Foreign body suspect
* Clean airways prior to rhinoscopy
* Obtain samples for cytology
* Procedure
1. **GA and cuffed endotracheal tube**
2. Pack back of throat w/ gauze
3. Fill 20-30cc syringe w/ 0.9% saline
4. Place tapered end in nostril
5. Hold other nostril closed w/ finger
6. Flush saline quickly w/ a bit of force
7. Repeat several times
8. **Cats**: use dorsal recumbency w/ small towel rolled under neck
9. Can use Foley catheter for antegrade and retrograde flushes
32
What type of flush is this?
Nasal flush--normograde
33
What type of flush is this?
Nasal flush--retrograde
34
**Cytobrush samples**
Alternative to?
Technique: easy or difficult?
Quality?
Used for?
Procedure?
* Alternative to nasal flushing
* Easier technique
* Good quality cytological material
* Cytology and culture
* Local block, place into nose, swirl around, smear on slide
* No need to anesthetize patient
35
**Bronchioloar lavage**
Indications?
Undertaken how?
Can sample what?
* Indications: lung disease involving small airway, alveoli, interstitium (flush out certain sections of lungs)
* Can be undertaken via bronchoscope or blindly
* BAL: can sample specific diseased lung lobes
36
**Indications for transtracheal washes & aspirates: airway or lung parenchymal disease**
Transtracheal wash & aspirate vs. endotracheal or transoral wash & aspirate
* Transtracheal wash and aspirate
* Medium-larger breed dogs
* +/- sedation
* Landmark: cricothyroid ligament
* Go through transtracheal rings (less likely to hit nerve)
* Endotracheal or transoral wash & aspirate
* Cats and tiny dogs
* GA required
* Catheter down ET tube
37
**Transthoracic lung aspiration**
Indications?
Guidance?
Complications?
* Intrathoracic mass lesions in contact w/ thoracic wall
* Ultrasound guidance improves diagnostic yield and safety
* Complications
* Hemothorax
* Pneumothorax
* Potentially pyothorax later on
38
When is a chest tube indicated?
* Treatment of pyothorax
* Management of pneumothorax when air is continually accumulating
39
**Review respiratory therapeutics**
Antibiotics: considerations?
Glucocorticoid differences
* Antibiotics--considerations
* What organisms are likely?
* What antibiotics penetrate resp tissue?
* Which part of resp system are you treating?
* Which species of animal are you treating?
* Glucocorticoids:
* Differences between anti-inflammatory doses vs. immunosuppressive doses?
* Difference btn prednisolone, dexamethasone, methylprednisone?
40
**Review respiratory therapeutics**
Bronchodilators
Anti-tussives
Nebulization + coupage
* Bronchodilators--usually for bronchitis
* May allow dose reduction of glucocorticoids in some cases of allergic bronchitis
* Antitussives--used mainly in dogs w/ dry and non-productive cough due to airway collapse or irritant tracheitis
* **Avoid in moist coughs**
* Nebulization + coupage
* Improves hydration of lower airways
* Can administer some antibiotics via this method
41
**Therapeutics: oxygen**
Indications?
Methods?
* Indications
* To treat hypoxemia (PaO2 \< 90%)
* To dec. workload of heart and lungs
* Methods
* Face mask--quick, cheap
* Requires high O2 flow
* Must stay w/ patient
* Nasal catheter
* Patient can move around more
* Watch flow rate
* Cage--more expensive
* Humidity and temp controlled
* Opening doors decreases O2
* Intratracheal--emergency
* +/- sedation/anesthesia or tracheostomy tube
* Continual monitoring
