Dz of the Pulmonary Artery & the Pleural Space Flashcards
1
Q
Pulmonary Hypertension occurs if
A
> 30 mm Hg
2
Q
Mild hypertension is considered…
A
30-55 mmHg
3
Q
Moderate hypertension is considered
A
56-79 mmHg
4
Q
Severe pulmonary hypertension is considered when…
A
> 80 mmHg
5
Q
Explain the pathogenesis of pulmonary hypertension.
A
6
Q
What are the 6 main groups used to classify pulmonary hypertension?
A
- Arterial dz (idiopathic pulm hypertension, congenital L-R shunts)
- L Heart dz (L-sided valvular heart dz, L-sided cardiomyopathy)
- Resp Dz/Hypoxia (chronic obstructive pulm dz, interstitial lund dz, alveolar hypoventilation disorders)
- Pulmonary thromboembolism (pulm thromboembolism, neoplasia)
- Parasitic (Dirofilaria, Angiostrongylus)
- Multifactorial
7
Q
What are clinical signs of pulmonary hypertension?
A
- secondary to underlying dz
- secondary to pulmonary hypertension –> resp distress, exercise intolerance
- heart sounds (+/- tricuspid murmur or split S2)
8
Q
What clinical findings are secondary to and strongly suggestive of pulmonary hypertension?
A
- syncope w/o any other identifiable cause
- respiratory distress at rest
- activity or exercise terminating in respiratory distress
- R-sided heart failure - cardiogenic ascites
9
Q
What clinical findings are secondary to and possibly suggestive of pulmonary hypertension?
A
- tachypnea at rest
- increased respiratory effort at rest
- prolonged exercise or post-activity tachypnea
- cyanotic or pale MMs
10
Q
How does an echocardiogram help diagnose pulmonary hypertension?
A
- Looks for tricuspid regurgitation to estimate systolic pressure
- Pulmonic regurgitation to estimate diastolic pressure
- modified bernoulli equation +/- RV remodeling
11
Q
What additional tests can be used to diagnose pulmonary hypertension?
A
- Rads/CT
- Haematology & biochemistry
- Heartworm/F. Heartworm
- Bronchoscopy
- BAL
12
Q
What txt is there for pulmonary hypertension?
A
- exercise restriction
- treat underlying cause
- phosphodiesterase inhibitor - Sildenafil
13
Q
Pulmonary thromboembolism is the obstruction of…
A
pulmonary vessel (s) by a blood clot
14
Q
Explain Virchow’s Triad and how it relates to pulmonary thromboembolism.
A
- Endothelial injury: Neoplasia, sepsis, indwelling venous catheters, pancreatitis, other inflammatory diseases
- Hypercoagulability: protein-losing nephropathy, protein-losing enteropathy, hyperadrenocorticism, dirofilariasis, IMHA
- Abnormal blood flow: cardiac dz, trauma w/ crush injury, neoplasia
15
Q
What clinical signs may occur with pulmonary thromboembolism?
A
Acute on initial presentation, dyspnoea, tachypnea, lethargy, C, haemoptysis, cyanosis, death
16
Q
Clinical signs are dependent upon…
A
degree of thrombosis
underlying cause
17
Q
What tests could you do to diagnose pulmonary thromboembolism?
A
- Blood gas analysis
- Rads
- PT/PTT
- TEG
- D-dimers
- CT
- Echo
18
Q
Txt is critical for pulmonary thromboembolisms because…
A
it has a high mortality rate because p will continue to throw clots around the body, including to critical organs
19
Q
What txt should be used for supportive txt of pulmonary thromboembolism?
A
- Oxygen therapy
- pulmonary hypertension –> Sildenafil
- Bronchodilators –> Methylxanthines
20
Q
What drugs are used to prevent further thrombus?
A
Anticoagulants - Clopidogrel, LMWH
Thrombolytic agents are not recommended because o the risk of bleeding
21
Q
Where do the adult stages of Dirofilaria immitis live?
A
Heart & pulmonary artery
22
Q
Adult worms of Dirofilaria immitis cause…
A
inflammation, vascular dysfxn, pulmonary hypertension, pulmonary thromboembolism
23
Q
What is Wolbachia?
A
A symbiotic bacteria with Dirofilaria immitis
24
Q
Describe the clinical signs for Dirofilaria immitis in mild, moderate, severe, and caval syndrome cases.
A
- Mild: Asymptomatic or C
- Moderate: C, exercise intolerance, abnormal lung sounds
- Severe: C, exercise intolerance, dyspnea, abnormal heart & lung sounds, hepatomegaly, syncope, ascites, death
- Caval syndrome: Sudden onset of severe lethargy & weakness accompanied by hemoglobinemia & hemoglobinuria
25
How would you diagnose Dirofilaria immitis infection with bloods?
Antigen, Mod Knott or Filtration test, Antibody test
26
What are the pros/cons of the bloods tests for heartworm?
* Antigen: For female adults only, False + rare, False - if low burden/ male only/ immature females/ antigen-antibody complexes
* Mod Knott or Filtration Test: For microfilaria, 20% of afilaremic dogs which is higher if preventative txt given
* Antibody test: only confirm exposure, 85% sensitivity, mostly for cats
27
What further diagnostic tests could be used to assist with diagnosing Dirofilaria immitis and what would you expect to find on those tests if positive?
* Rads: look for enlarged tortuous pulmonary vessels, parenchymal changes, R-heart enlargement
* Echo: worms, remodelling, pulmonary hypertension
28
Adjunct Txt has a risk of complications during adulticide txt in Dirofilaria infection. What is it?
Dead worm reaction which can lead to pulmonary embolism and inflammation
29
How do you minimise the risk of the dead worm rxn in Adjunct txt of Dirofilaria infection?
Minimise risk by strict rest and glucocorticoids to reduce clinical signs
30
Prior to Adulticide txt of Dirofilaria immitis, what should be administered and why?
* Macrocytic lactones as a filaricide
* Doxycycline for Wolbachia bacterial infection & release from the worms
31
Explain adulticide treatment of Dirofilaria.
* Melarsomine on Day 60, 90, and 91 after adjunct txt.
* Strict rest for 6-8 wks following last Melarsomine
* Glucocorticoids to reduce clinical signs
* Retest with antigen test 9 months after treatment
* Sx removal if heavy burdens or caval syndrome
32
You live an an endemic area for Dirofilaria immitis. How should you prevent infection with this worm in your dog?
* Macrocytic lactones (Ivermection, Selamectin, Moxidectin, Milbemycin oxime) q 30 days, 12 months/yr, starting from 8 wks of age and perform annual testing
33
Macrocytic lactones kill what stages of Dirofilaria immitis?
Microfilaria, 3rd & 4th stage larvae
34
Explain Dirofilaria immitis in cats
* often low worm burden
* 1/3 single sex population
* signs relate to the arrival of worms in the pulmonary vessels or death of worms
* Prevent the same way as dogs
* Dx: Antibody test
* Txt: Prednisolone, **No Melarsomine**
34
What is pleural effusion?
build-up of fluid btw layers of tissue that line lungs & chest cavity
35
Transudate pleural effusion is...
pure or modified
36
exudate pleural effusion is...
septic or aseptic
37
What are clinical signs of pleural effusion dependent on?
* rate of accumulation
* volume
* type of fluid
* cause
* concurrent dz
38
What are clinical signs of pleural effusion?
tachypnea, dyspnea, cyanosis, open-mouth breathing
restrictive breathing pattern, dull lung sounds in ventral thx, dull percussion
39
What is the initial mgmt of pleural effusion?
* minimise stress --> mild sedation (butorphanol)
* oxygen
* ultrasound & thoracocentesis (Dx & therapeutic)
40
How would you analyse fluid from pleural effusion?
Macroscopic eval: Blood (coag test, trauma, neoplasia), white & opaque (chylothx), others: transudate or exudate
41
Pure transudate from pleural effusion would have what cytological findings?
macrophages, mesothelial cells, non-degenerate neuts
42
Modified transudate from pleural effusion would have what findings on cytology?
macrophages, mesothelial cells, & increasing numbers of lymphocytes, & non-degenerate neuts
43
What would non-septic exudate from pleural effusion have on cytology?
neutrophils & macrophages
44
What would septic exudate from pleural effusion have on cytology?
degenerate neutrophils, intracellular & extracellular bacteria, macrophages
45
Decreased oncotic pressure with a pure transudate in pleural effusion means...
Hypoalbiminemia (protein-losing nephropathy/enteropathy, liver failure, etc)
46
Increased hydrostatic pressure from modified transudate in pleural effusion means...
congestive heart failure, pulmonary thromboembolism, lung lobe torsion, neoplasia
47
Increased vascular permeability in exudate from pleural effusion is a sign of...
systemic inflammation, local infection (pyothx), systemic infection, neoplasia
48
What further tests can be used to diagnose pleural effusion?
ultrasound & -centesis
fluid analysis
blood tests (hematology, biochemistry, coagulation testing)
Rads, Echo CT
49
How would you treat pleural effusion?
* drainage
* treat underlying dz
50
What is pyothorax and what is it typically caused by?
Infection of pleural space
Causes: FB, perforating wound, pneumonia, translocation
51
How do you treat pyothorax?
* drain placement +/- lavage
* antibiotics, empirical or based on C&S
* Supportive care
* +/- Sx
52
What is chylothorax and what is it often caused by?
Build up of chyle
Causes: idiopathic, R-sided heart failure, neoplasia/mass, thromboembolism, lung lobe torsion
53
how would you medically manage chylothorax?
Thoracocentesis
Meds: Rutin, Octreotide (EH...)
Diet: low-fat
spontaneous resolution may occur
54
When would you do surgical management of chylothorax? And what options for procedures are open to you?
* In idiopathic dz
* Thx duct ligation, subtotal pericardiectomy, pleuroperitoneal shunting, pleurodesis
55
What is Pneumothorax? What often causes it?
Air build up
Causes: trauma (open or closed), iatrogenic, spontaneous (idiopathic, bulla, pneumonia)
56
How might you diagnose pneumothorax?
Imaging: rads, ultrasound (EMERGENCY), CT
57
What are the two types pneumothorax that you need to be able to differentiate?
Tension vs non-tension
58
What txt is used for pneumothorax?
drainage, sx, pleurodesis
