Diseases of the Respiratory System Flashcards
What are some of the common causes of respiratory failure?
Airway obstruction Ruptured diaphragm Pulmonary oedema/haemorrhage Pneumothorax Neoplasia Infection Toxin exposure
What are some of the signs associated with respiratory failure?
Cyanosis
Inspiratory/expiratory dyspnoea
Tachycardia, weak pulses
Collapse/unconsciousness
What is orthopnea?
Abduction of elbows and extension of neck to aid breathing
What are the sounds associated with inspiratory dyspnoea?
snoring
stertor
stridor
What are the sounds associated with expiratory dyspnoea?
Wheezes
crackles on auscultation
List some methods of oxygen administration
ET tube Flow by Nasal catheter Face mask Oxygen tent Oxygen cage/incubator
Aside from an ET tube, what is another method of maintaining a patent airway?
Tracheostomy tube (requires constant monitoring)
What are some common clinical signs of upper respiratory tract disease?
Nasal discharge
Sneezing/reverse sneezing
Stertor/snoring
Systemic/CNS signs
How might nasal discharge appear?
Serous
Mucopurulent
Haemorrhagic
What factors should be examined for suspected upper respiratory tract disease?
Breathing noises
Nasal discharge, planum depigmentation
Assess regional lymph nodes
Retropulsion of eyeballs/exophthalmia
Dental disease
Name some inflammatory causes of nasal disease
Idiopathic
allergic
irritation
Name some infectious causes of nasal disease
Bacterial/viral/fungal/parasitic
Name some viral causes of nasal disease
Herpesvirus and calicivirus in cats
Canine distemper
Name some fungal causes of nasal disease
Aspergillus in dogs
Cryptococcus in cats
Name some parasitic causes of nasal disease
Pneumonyssus caninum in dogs
Cuterebra sp.
What are the main categories in differential diagnosis for nasal disease?
Inflammatory Infectious Neoplasia Trauma/fracture Foreign body Systemic causes (epistaxis)
What are some systemic causes of nasal disease?
Coagulopathy
Hyperviscosity syndrome
Systemic hypertension
What is one of the main anatomical reasons for nasal disease?
Brachycephalic syndrome
What lab investigations can be done to help diagnose upper respiratory tract disease?
Tests for bleeding disorders
Serology for fungal disease
Viral testing in cats
What investigations can be done under GA to help diagnose upper respiratory tract disease?
Full oral examination
Dental probing
Nasopharyngeal swab in cats
What imaging investigations might be carried out to help diagnose upper respiratory tract disease?
Intra-oral nasal x-ray
CT scan of head for better detail
Why might endoscopy be helpful in diagnosing upper respiratory tract disease?
Retrograde view of nasopharynx
Anterograde rhinoscopy
Nasal flush can be diagnostic and therapeutic
Nasal biopsy useful for histopathology and culture
Why is it important to check coagulation factors before performing a nasal biopsy?
Nasal tissue is highly vascularised and can bleed profusely
How can bleeding be made less severe during rhinoscopy investigations?
Ice packs on nose
Intranasal adrenaline/soaked swabs
Which types of dogs are predisposed to Aspergillus infections?
Meso/dolicocephalic breeds
How does Aspergillus cause damage to the upper respiratory tract?
Production of aflatoxins by the fungus provokes a profound inflammatory response
Causes extensive turbinate and bone destruction
Which type of cat is predisposed to Aspergillus felis?
Brachycephalic breeds
What are the clinical signs of Aspergillus infection?
Mucopurulent nasal discharge or epistaxis (uni/bilateral)
Sneezing
Nasal pain
Nasal depigmentation
Which methods might help diagnose an Aspergillus infection?
Imaging Rhinoscopy Cytology and histopathology Fungal culture Serology and PCR
What might be seen on an Aspergillus radiograph?
Turbinate destruction
Increased soft tissue opacity
Increased soft tissue density in frontal sinuses
What are the main methods of treating Aspergillus infections?
Topical antifungal application into the nasopharynx and rostral nasal cavity
Trephination and flushing with saline then clotrimazole flush
What are the main anatomical abnormalities in dogs with BOAS?
Excessive soft tissue
Stenotic nares
Elongated soft palate
Hypoplastic trachea
What are the secondary problems caused by BOAS?
Laryngeal collapse and hiatal hernia
How do BOAS animals present?
Loud breathing Snoring Heat/exercise intolerance Gagging/regurgitation/vomiting Sleep deprivation
What tests might be used to diagnose BOAS?
Examination under sedation
Fluoroscopy/barium swallow
CT/x-ray of head and/or chest
Rhinoscopy
How does laryngeal paralysis occur?
Can be congenital/trauma/nerve infiltration
How does laryngeal paralysis present?
Exercise intolerance
Inspiratory stridor and a soft ineffective cough
How is laryngeal paralysis diagnosed?
Laryngeal exam under sedation/GA
What are the main nursing considerations for patients with laryngeal paralysis?
Keep animal calm and cool
Provide oxygen
Monitor for signs of aspiration pneumonia/dysphagia/megaoesophagus
Steroids to reduce oedema
Surgical intervention often required
In which dogs is tracheal collapse most commonly seen?
Small/toy breeds
Which part of the trachea is more prone to collapse?
Most common at thoracic inlet
What causes tracheal collapse?
Unknown aetiology - obesity may be a predisposition
What is the main sign of tracheal collapse?
‘Goose honking’ cough
How is tracheal collapse diagnosed?
Physical exam
X-ray/fluoroscopy with assess tracheal positioning
What are the nursing considerations for tracheal collapse?
Sedation (butorphanol) Anti-tussive/bronchodilators/corticosteroids Exercise restriction Oxygen therapy Intubation if acute respiratory episode
What are the long-term solutions for tracheal collapse?
Weight loss
+/- surgery (stent)
what is a cough?
a sudden respiratory effort against a closed epiglottis, resulting in a sudden noisy expulsion of air from the lungs
what is dyspnoea?
difficulty breathing; increased respiratory effort
what is hyperpnoea?
increased respiratory effort without dyspnoea
what is orthopnoea?
adopting a posture to facilitate breathing - usually sit/stand with elbows abducted and neck extended
what is the aim of a cough?
protective reflex to clear excess secretions/foreign material
where are the cough receptors?
in large airways
low density of cough receptors in nose/sinuses/pharynx/pleura
what is the cough arc reflex?
afferent = sensory nerves (vagus)
cough centre = medulla oblongata
efferent = via vagus, phrenic and spinal motor nerves to diaphragm/abdominal wall/muscles
what cardiovascular condition can also be associated with a cough?
congestive heart failure due to enlarged left atrium
oedema causes more tachypnoea
what are the harmful effects of chronic coughing?
exacerbates airway inflammation and irritation
emphysema
pneumothorax
weakness and exhaustion
dissemination of infections
what are the clinical signs of a cough?
coughing tachypnoea and dyspnoea exercise intolerance weakness, syncope cyanosis
what are the main differential diagnoses for cough/dyspnoea?
BOAS laryngeal paralysis kennel cough tracheal collapse chronic bronchitis asthma (cat) pneumonia lungworm pneumothorax pleural effusion
what should be involved in physical examination of a coughing/dyspnoeic patient?
posture
RR and rhythm, effort
–> listen for stertor/stridor/wheezing
thoracic auscultation (breathing and heart sounds)
how can you investigate coughing/dyspnoea?
clinical pathology
assessment of oxygenation
laryngeal examination
imaging
assessment of pleural space disease
how would you assess the level of oxygenation in the patient?
SpO2 (pulse ox)
PaO2 (arterial blood gas analysis)
what are you looking for during radiography?
pulmonary patterns
heart and vessels
masses
pleural space
why might bronchoscopy be carried out when investigating cough/dyspnoea?
help collection of broncho-alveolar lavage (BAL)
aid to coupage
why might you want to collect fluid from a broncho-alveolar lavage?
assess cytology and bacterial culture
what equipment is required for a bronchoscopy?
endoscope syringes of sterile saline collection pots mouth gag urinary catheter crash box/induction agent
what nursing considerations are there during bronchoscopy?
requires several people, needs to be fast
coupage will be required
monitor patient carefully until full recovered
have assess to emergency drugs/oxygen
what is canine chronic bronchitis?
lower airway disease, chronic bronchial inflammation with over-secretion of mucus
which age dogs typically get chronic bronchitis?
common in middle aged to older dogs
what are some concurrent morbidities with chronic bronchitis?
tracheal/bronchial collapse
mitral valve disease
pulmonary hypertension
what is the pathophysiology of bronchitis?
smaller airways become obstructed by mucus
alteration to the mucociliary escalator
inflammation of the lower airways - narrowing, bronchomalacia, bronchiectasis
what is bronchiectasis?
end-stage bronchial change (widening and inflammation)
what are the clinical signs of canine chronic bronchitis?
chronic cough >2 months
+/- dyspnoea/tachypnoea
gagging/retching
pyrexia
wheezes, crackles if pneumonia
how is canine chronic bronchitis investigated?
bronchoscopy
bronchoalveolar lavage
what is typically seen on BAL of dog with bronchitis?
mucus and neutrophils
+/- bacteria
consider other cause if eosinophils
what are the management methods for bronchitis?
weight control
harness
avoid tobacco smoke/dust/airway irritants
medication
what medications might be used to manage/treat bronchitis?
glucocorticoids
bronchodilators
antibiotics if required
antitussives and mucolytics??
what is the first line antimicrobial used to bronchitis treatment?
doxycycline - broad spectrum, empirical treatment for 7-10 days (+1 more week if positive response)
which medications for bronchitis might be nebulised?
corticosteroids (fluticasone) and bronchodilator (salbutamol)
not for antimicrobials
what is the prognosis for chronic bronchitis in dogs?
chronic and progressive but can live for years if well managed
worse if bronchiectasis or bacterial pneumonia
what is canine infectious tracheobronchitis also known as?
kennel cough
what is kennel cough?
a complex of several viruses, bacteria and other microorganisms
what viruses can be involved in kennel cough?
canine adenovirus 2
canine parainfluenza virus
canine herpes virus
what is the main bacterial causal agent of kennel cough?
Bordetella bronchiseptica
how is kennel cough treated?
antibiotics/antiinflammatories
antitussives
what conditions fall under feline lower airways disease (FLAD)?
feline asthma, feline bronchitis
what is FLAD?
chronic bronchial inflammation with mucus hypersecretion
which cats are more likely to suffer with FLAD?
young/middle-aged cats
siamese over-represented
what is the essential difference between FLAD and canine lower airway diseases?
FLAD often causes bronchoconstriction
what is the pathophysiology of FLAD?
type I hypersensitivity leading to histamine and serotonin production by mast cells
smooth muscle contraction (bronchoconstriction)
Oedema and eosinophilic inflammation of the lower airways
mucus hypersecretion
obstruction of bronchus
what are the clinical signs of FLAD?
cough
dyspnoea/tachypnoea
cyanosis
wheezing
crackles if emphysema
dull lung sounds if pneumothorax
how is FLAD investigated?
chest x-rays/CT scan
bronchoscopy
bronchoalveolar lavage
what investigations might be done into the BAL fluid with FLAD?
cytology - mucous and inflammatory cell count
Bordetella bronchiseptica and Mycoplasma spp. PCR
faecal parasitology
bacterial culture
what nursing considerations are there for emergency FLAD?
stress-free environment
sedation (butorphanol)
provide oxygen ASAP
bronchodilators
corticosteroids
why is nebulisation not recommended for FLAD patients?
could cause bronchoconstriction
what medications might be used to control FLAD longer term?
glucocorticoids
bronchodilators (theophylline orally)
doxycycline if mycoplasma infection
Fenbenzadole if parasitic infection
what is the prognosis for FLAD?
variable
chronic - good if treated appropriately
acute - can be fatal if management not prompt
what are the classes of pulmonary parasites?
intestinal worms
lungworms
heartworms
what is the most common type of heartworm in dogs?
angiostrongylus vasorum
what is the pathogenesis of angiostrongylus?
infection by eating intermediate host (mollusk) or paratenic host (frog)
L3 larvae liberated in intestines and travel to pulmonary vasculature
adult worms live in the pulmonary arteries and right side of heart
larvae migrate into alveoli and are coughed and swallowed
what are the clinical signs of angiostrongylus infection?
chronic cough, acute dyspnoea
severe pulmonary hypertension
syncope
increased bleeding tendency - unknown mechanism
neurological signs - CNS haemorrhage
how can suspected angiostrongylus be investigated?
chest x-rays/CT scan
angio detect (blood test) - antigen detection PCR
faecal smear
Baermann faecal examination
empirical treatment
what is the treatment for angiostrongylus vasorum infection?
moxidectin or fenbenzadole (antithelmintics)
what are the side effects of antithelmintic treatment for angiostrongylus vasorum?
watch out for post-treatment reaction - dyspnoea, ascites and sudden death
what is the prognosis for angiostrongylus vasorum infection?
depends on severity of clinical signs
what is bacterial pneumonia?
secondary bacterial mixed flora infection
can be acute or chronic and affect one or more lung lobes
how is bacterial pneumonia spread?
inhaled bacteria/haematogenous spread
what are some of the predisposing causes for bacterial pneumonia?
chronic bronchitis bronchiectasis immunosuppression foreign body aspiration
what are the clinical signs of bacterial pneumonia?
soft productive cough, mixed dyspnoea, tachypnoea, exercise intolerant
crackles +/- wheezes on auscultation
systemic: pyrexia, lethargy, inappetence
what investigations can be done to help diagnose bacterial pneumonia?
chest x-rays/CT scan
haematology (neutrophilia/neutropenia)
C reactive protein (inflammation)
SpO2/ABG
why should you wait for culture results when treating bacterial pneumonia, rather than treating empirically?
high risk of developing bacterial resistance
what treatment might be used for aspiration pneumonia?
IV amoxycillin-clavulanic acid
what is used in the empirical treatment of bacterial pneumonia?
PO doxycycline
what is used in treatment of patients with septic bacterial pneumonia?
IV fluoroquinolones plus ampicillin or clindamycin
what are the nursing considerations for patients with bacterial pneumonia?
oxygen supplementation if hypoxic
fluid therapy
nebulisation to increase mucus fluidity
bronchodilators
what is the prognosis for bacterial pneumonia?
depends on severity of clinical signs
pneumothorax and abscessation may require lung lobectomy
what happens to the lungs during pneumothorax?
gradual collapse of the lungs, increase in intrathoracic pressure (becoming positive)
what are the cardiac effects of pneumothorax?
decreased cardiac output
cardiac arrest
what is the clinical presentation of a pleural space disease?
tachypnoea
restrictive dyspnoea
paradoxical breathing
what happens to the lung sounds in an animal with pleural effusion?
muffled lung sounds ventrally
decreased resonance ventrally
what happens to the lung sounds in an animal with pneumothroax?
absent lung sounds dorsally
increased resonance dorsally
what are the signs that an animal is in respiratory distress?
orthopnoea
restrictive dyspnoea
mouth-breathing + respiratory noises
tachy/hyperpnoea
cyanosis
how is pleural space disease diagnosed?
chest radiographs
thoracic ultrasound
thoracocentesis with fluid analysis
what will be seen on a chest radiograph of a patient with pleural space disease?
decreased details
reduced cardiac silhouette
rounded lung margins
what types of analysis should be done on the pleural fluid?
cytology (EDTA tube)
culture (plain tube)
biochemistry (plain tube)
what is a thoracocentesis?
aspiration of air/fluid from the pleural cavity by inserting a needle/catheter/drain via a caudal rib space
where is a thoracocentesis performed?
around the level of the 7-8th rib space
which aspect of the rib should a thoracocentesis be performed on?
cranial aspect - caudal has nerves/blood vessels
what is pure transudate?
protein-poor, clear fluid
TP <20g/L
what is modified transudate?
yellow, blood-tinged fluid
protein rich
TP >20g/L
what is exudate?
turbid fluid
TP >20g/L
why might an animal have a pure transudate effusion?
Hypoalbuminaemia
due to liver failure, protein-losing enteropathy/nephropathy
why might an animal have a modified transudate effusion?
congestive heart failure
pericardial disease
neoplasia
diaphragmatic rupture
what types of cells are present in non-septic exudate?
neutrophils
macrophages
eosinophils
lymphocytes
why might an animal have non-septic exudate?
FIP neoplasia diaphragmatic hernia lung lobe torsion resolving pyothorax
what types of cells are present in septic exudate (pyothorax)?
degenerate neutrophils
possibly intra/extracellular bacteria (anaerobic, foul-smelling)
what are the possible causes of pyothorax?
bite
foreign bodies
iatrogenic
parapneumonic
what is chyle?
fluid with milky appearance, TP >25g/L
mainly small lymphocytes and triglycerides
what are the causes of chylothorax?
idiopathic cardiac disease (cats) cranial vena cava thrombosis/mass heartworm disease neoplasia
what is haemothorax?
collection of blood-containing fluid in the pleural cavity
how much blood needs to be present in the fluid for it to be considered a haemothorax?
Hct >20% OR >50% normal patient hct
what are the causes of haemothorax?
anticoagulant rodenticide coagulopathy lung lobe torsion trauma neoplasia (rib)
what are the complications of thoracocentesis?
pyothorax or pneumothorax
how are pleural effusions treated?
thoracocentesis
treatment of underlying cause (e.g. chemo, lobectomy for torsion or diaphragmatic rupture)
how is pyothorax treated?
IV antibiotics (de-escalation if possible)
therapeutic drainage +/- lavage
surgery
how is chylothorax treated?
management of underlying disease
Rutin
surgery for idiopathic causes
may heal spontaneously (traumatic rupture)
what are the causes of pneumothorax?
trauma
spontaneously (blebs, bullae, chronic airway disease)
iatrogenic
how does pneumothorax appear on auscultation?
no lung sounds audible on dorsal aspect
hyper-resonant percussion
how is pneumothorax diagnosed?
radiography (heart does not sit against ribs ventrally)
ultrasound
how is pneumothorax treated?
rest
thoracocentesis as required/chest drain
oxygen therapy
may require exploratory thoracotomy if recurrent
what are the nursing considerations for pneumothorax?
delay diagnostics until stable
stress = death, consider sedation
obtain SpO2, supplement oxygen
cover any obvious chest wounds
prepare for thoracocentesis
what are the roles of the vet nurse during pleural disease cases?
chest drain care
oxygen and fluid therapy
observation and monitoring
medication (inc. analgesia)
shock treatment
recumbent patient care
feeding and exercise adjustments
