38 Disorders of the Pleural Cavity

Pyothorax

What is the name for septic exudate of the pleural cavity

Decreased lung sounds, tachypnea, fever, weight loss. Similar signs to pleural effusion and abscess formation

Name a couple things you might observe on a physical exam with a pyothorax

Thoracic radiographs and cytologic exam of pleural fluid (like thoracocentesis)

How do you diagnosed pyothorax?

TRUE

TRUE OR FALSE: most pleural effusions are bilateral in cats and dogs

Pyothorax

Which problem presents as septic suppurative inflammation on cytology?

Antibiotics, drainage of pleural space and supportive care

What is the TREATMENT OF CHOICE for pyothorax?

ANAEROBIC: ampicillin (#1 choice)

GRAM NEG: fluoroquinolones

Anaerobes and gram negative bacteria are typically present in pyothorax. What are the antibiotics of choice for treating this problem?

SHOULD: heparin

SHOULD NOT: antibiotics

Chest tube placement and lavaging of the pleural space is a good treatment of pyothorax. What should you and should you NOT add to the lavage for treatment?

For those not responding to medical therapy

Why would you perform a thoracotomy in a patient with a pyothorax?

Chylothorax

This is accumulation of chyle in the thoracic cavity, originating from the *thoracic duct*

Triglycerides, small lymphocytes, protein and fat soluble vitamins

Name the things contained in the "chyle" that causes a chylothorax (things you will see when you evaluate the effusion)

Idiopathic

What is the number 1 cause of chylothorax (though there are LOTS of etiologies)?

Pyothorax

note: this is septic exudate. septic exudate is the substance that causes the pyothorax condition

If I were to tell you this effusion smells very bad (which you find out is due to anaerobic bacteria) and you can see that the left lung lobes are fibrinous and collapsed, what is your first differential for what type of effusion this is?

Lung lobe torsion

What is this?

Chylothorax

What kind of pleural effusion are the following breeds predisposed to:

Afghan hounds, Shiba Inu, Siamese and Himalayan cats

Low fat diet, administer rutin (a nutraceutical that dec. protein content of effusion)

How can you medically manage a chylothorax?

Surgical ligation of the thoracic duct and pericardectomy

How can you surgically manage chylothorax?

CT Lymphangiogram

What diagnostic test can you do when you inject contrast into lymph nodes and thoracic ducts to see if it dumps into the chest cavity (abnormal)?

Rupture of cavitary lesions

What causes a spontaneous pneumothorax?

Pulmonary bleb

What is this, present in the lung of a dog that presented with spontaneous pneumothorax?

Spontaneous pneumothorax

Bullaes, Paragonimus infection, necrotic neoplasia, abscesses and granulomas, all of these things which cause cavitary lesions may lead to what abnormality?

Pulmonary bullae

What is this?

FALSE: do NOT put a needle into this cystic structure because it will just continue to leak

TRUE OR FALSE: You should put a needle into a pulmonary bullae to drain it and stop spontaneous pneumothorax

BLEB = under 1 cm, smaller thin cystic structure full of air on the surface of the lung not visible on radiographs

BULLAE = over 1 cm, air filled cystic structure visible on radiographs

What is the difference between a pulmonary bleb and a pulmonary bullae?

Pulmonary bullae (may lead to spontaneous pneumothorax)

What is this?

Neoplastic (large lymphocytes = larger than neutrophils)

What type of effusion is this?

Septic exudate (bacteria visible in neutrophils)

What type of effusion is this?

Chylous

A 4 year old female domestic short hair presented with tachypnea and shallow breathing. There are muffled heart and lung sounds ventrally. You find the triglyceride count to be higher in the effusion than serum. This is what cytology shows. What type of effusion is it?

TONS OF AIR = pneumomediastinum

A geriatric canine presents with a large ventral cervical mass. There is no upper airway obstruction, but he is uncomfortable on inspiration. What do you think when you see this radiograph?

Non septic exudate

What type of effusion is this?

Chylous

What type of effusion is this?

Often self limiting 10-14 days. (Dogs often more severe = pneumomediastinum)

What is the outlook like for cats with tracheal tears?