Pneumothorax

Question 1

Etiology

Answer 1

Traumatic
Iatrogenic
Spontaneous:
Primary (idiopathic) spontaneous pneumothorax
Rupture of blebs and/or bullae
Large-breed, middle-aged to old, deep-chested dogs
בלב הינו מתחת לפלאורה, בולה היא כיס אוויר ברקמת הריאה עצמה

Secondary spontaneous pneumothorax
Abscesses, granulomas, neoplasia, lung worms (paragonimus, dirofilaria), pneumonitis, foreign body, asthma (cats)
Esophageal origin (accompanied by pyothorax)

Question 2

Pathophysiology

Answer 2

Increased intra-thoracic pressure
Collapsed lungs:
V-Q mismatch
Hypoxemia
Hypercapnia

Decreased venous return, increased pulmonary vasoconstriction
Decreased cardiac output
Hypotension

Tension pneumothorax (one-way valve) leads to rapid and dramatic increases in intra-thoracic pressures and is life-threatening
Hypotension, shock, severe hypoxemia and hypercapnia

Question 3

cxr

Answer 3

CXR establishes diagnosis, may reveal underlying cause
Repeat CXR after thoracocentesis
CT improves sensitivity

Question 4

tx

Answer 4

Traumatic pneumothorax may only require monitoring
In other cases, intermittent thoracocentesis/chest tubes, oxygen therapy*
Lesions heal within 3-5 days in most cases
Secondary spontaneous pneumothorax may require surgery
Abscess, granuloma, neoplasia, foreign body
In cats, most cases of spontaneous pneumothorax are secondary
In cats, most cases of spontaneous pneumothorax are successfully managed with conservative treatment (monitoring, thoracocentesis)
In dogs, most cases of spontaneous pneumothorax (~70%) are primary/idiopathic (from bullae/blebs)
In dogs, surgery is often recommended to remove affected tissue