Pleural disorders Flashcards
Pleural effusion and pneumothorax
Signalment?
Respiratory signs?
- Cats and dogs of any age
- Resp signs
- Rapid shallow breathing (restrictive breathing pattern); tachypnea
- Dyspnea
- Poss. open-mouthed breathing
- Cyanosis
- Exercise intolerance
- Non-respiratory signs: anorexia and lethargy
Pleural effusion and pneumothorax
Physical examination
- +/- pyrexia (depends on underlying disease)
- Barrel-shaped chest, esp. pneumothorax
- Muffled heart sounds and diminished/muffled lung sounds ventrally
- Dorsal–inc. lung sounds = pleural effusion (fluid at bottom–> lungs float to top)
- Dorsal–dec. lung sounds = pneumothorax
What does this indicate?
Pleural effusion
What is pleural effusion? What are the different types of fluid?
- Accumulation of excessive amounts of fluid w/in pleural space
- Exudate (pyothorax) = >3.0 protein + >7000 cell
- Transudate (CHF) = <2.5 protein + <1500 cell
- Modified transudate = 2.5-7.5 protein + 1000-7000 cell
- Hemorrhage (trauma)
What are the various exudative pleural effusion types?
- Hemorrhage
- Bile
- Chyle
- Septic
- Bacterial (pyothorax)
- Aseptic
- Neoplasia
- Feline infectious peritonitis
Pleural effusion
Mechanisms of fluid accumulation?
- Decreased oncotic pressure (hypoalbuminemia)
- Increased hydrostatic pressure (CHF)
- Increased capillary membrane permeability (inflammation due to FIP, neoplasia, pyothorax)
- Lymphatic malfunction (obstruction or lymphagiectasia)
Pleural effusion
What is done once pleural effusion is suspected after auscultation (2 things)?
-
Stabilize first
- Thoracocentesis
- Thoracic radiographs
Pyothorax
Etiology
- Dogs–secondary to inhaled foreign bodies or penetrating injury, pneumonia
- Cats–secondary to bite wounds, oropharyngeal aspiration or URTI
Pyothorax
Diagnosis
- Relatively straight-forward
- Thoracocentesis
- Cytology–degenerative neuts; bacteria
- Culture (aerobic and anaerobic), gram stain helpful
- Imaging–radiographs, CT
Pyothorax
Treatment: drain/lavage?
- Drainage and lavage through thoracotomy tube (chest drain)
- Unilateral or bilateral
- Unilateral–dogs, or unilateral effusions
- Bilateral–cats, or effusions with multiple pockets/abscesses
- Unilateral or bilateral
- Lavage
- Warm saline 10-20ml/kg into chest over 3-5 min in lat recumbency, rotate, then aspirate out
- Repeat 2-4x daily for 2-5 days
- Record amount of fluid into/out of pleural space
Pyothorax
Treatment: antibiotics?
- Long-term antibiotics based on culture
- Dogs–start w/ amoxyclav and metronidazole
- Cats–start w/ amoxyclav, enrofloxacin, and metronidazole
- If no culture, base on cytology
- Nocardia spp–TMS
- Actinomyces spp and Pasteurella spp–penicillins
- Anaerobes–metronidazole, penicillins, clindamycin
If there’s no improvement w/in 3-4 days after antibiotics for a pyothorax, what should be done?
Surgical exploration–FB/abscess–thorough lavage
What can cause a chylothorax?
Any disease that increases systemic venous pressure
What are 7 possible causes of accumulation of chyle in the pleural space?
- Trauma–rupture of thoracic lymphatic duct
- Neoplasia–cranial mediastinal mass, heart-based tumor, R atrial hemangiosarcoma
- Cardiac disease–cardiomyopathy, RCHF, pericardial disease, HW
- Thoracic duct lymphangiectasia
- Inflammation–fungal
- Lung lobe torsion
- Idiopathic, 60-70% cases have no underlying cause
How do you diagnose a chylothorax?
Thoracocentesis
Triglycerides in fluid > triglycerides in serum
What is a possible sequela to a chylothorax?
Restrictive pleuritis
