pleural space disease Flashcards
List 6 conditions which lead to the loss of thoracic capacity +/- cyanosis
pleural effusion
pneumothorax
Neoplasia (pleural or mediastinal)
Ruptured diaphragm
Abdominal abnormality e.g. severe ascites/ mass
Gross cardiomegaly
What is the pleural space
the narrow space between the parietal and visceral pleura
contains a small amount of serous fluid spread over the surface of the pleural
What is pleural space disease
accumulation of:
- fluid (pleural effusion)
- air (pnuemonthorax)
- soft tissue mass
in the pleural space
How does pleural space disease lead to difficulty breathing
there is direct compression of the lungs by fluid/air/mass
There is loss of negative pressure leading to lung collapse
If fluid –>this restricts the ability of the lungs to inflate so is known as restrictive lung disease
List 6 clinical signs of pleural space disease
‘restrictive’ breathing pattern= short shallow breaths
tachypnoea
open mouth breathing
dyspnoea, respiratory distress
orthopnoea
cyanosis
what is orthopnoea
the animal uses their entire body to breath - e.g. elbow adduction, sternal recumbency
List 3 findings on clinical exam that you might expect from a patient with pleural space disease
Observe the characteristic restrictive respiratory pattern
muffled heart/lung sounds
percussion of chest - dull ‘thud’ when there is a pleural effusion
Why might a pleural effusion form
If there is
- Decreased pleural fluid absorption into lymphatics
OR
- Increased fluid formation
List 6 reasons for increased fluid formation during a pleural effusion
‘leaky’ capillaries
Increase in intravascular pressure
Increase in lung interstitial fluid
Decrease in pleural pressure
Increase in pleural fluid protein
Disruption of thoracic duct or blood vessels
List 3 reasons for decreased fluid absorption in the pleural space during pleural effusion
Obstruction of draining lymphatics
Increased systemic vascular pressures
Reduced vascular oncotic pressure
T/F lung lobe torsion could cause chylothorax or haemothorax
True
Chylothorax -> occurs if there is disruption to the thoracic duct
Haemothorax -> occurs if there is bleeding
What is the most common cause of a pleural effusion with a Transudate
decreased oncotic pressure due to hypoalbuminaemia
Describe immediate treatment of pleural effusion
oxygen supplementation
Emergency thoracic ultrasound
If severely dyspnoeic do not radiograph- unstable and stressed
Thoracocentesis: provides immediate relief and stabilisation, can be diagnostic (cell counts, protein, bacterial cultrue)
Describe how you would perform a thoracocentesis for pleural effusion
clip and quick surgical prep
Butterfly needle/actheter at IC 6-8 (ICS 7 usually safe). Insert at level of the costochondral junction
Idealise localise a large pocket of fluid with ultrasound first
Use aseptic technique (colleages holds syringe while you remain sterile)
List 6 indications for a thoracostomy (chest drain)
Animals that will require multiple thoracocentesis over a short period of time
If large volumes of effusion
pneumothorax
chest wall injuries
most pyothorax cases
following chest surgery
Describe how you manage a plueral effusion case
Depends on cause –> ideally treat primary cause where possible
- Heart failure –> treat where possible
- pericardial effusion–> treat and drain
- pyothorax –> chest drain and lavage, need broad spectrum and anaerobe antibiotic coverage
- chylothorax –> diet and/or surgery
Describe a pneumothorax
Accumulation of air within the pleural space
Most commonly caused by trauma
T/F rupture of the oesophagus can produce pneumothorax
True
List 3 clinical findings of a pnemonthorax
restrictive breathing
auscultation reveals dull lung sounds dorsally, increased sounds ventrally
percussion–> increased resonance (like a drum)
How do you diagnose a pneumothorax
physical exam
assessment of resp status
thoracic radiographs- if stable enough
blood gases and pulse oximetry
Describe how you treat a pneumothorax
oxygen
drain pneumothorax as necessary, avoid over drainage
strict cage rest for 2 weeks
Describe signalment, diagnosis and treatment of thyoma
RARE commonest in older dogs
thoracic radiographs to confirm mass
present in resp distress +/- cranial caval syndrome
surgical resection as treatment of choice- good prognosis
Describe cranial caval syndrome
facial swelling like stung by lots of bees, mass pressing on cranial vena cava so causes problem with return of blood
Why is the pleural space having a negative pressure important
Means fluid wants to flow there
What is the mediastinum? What does it contain?
Space between the left and right pleural sac
Contains blood vessels, nerves, oesophagus heart, trachea etc
What is the most common form of pleural space disease
pleural effusion
In pleural effusion, what will you pick up on auscultation
Muffling of heart and lung sounds - especially ventrally when standing (due to gravity)
Name different types of fluid which can be present in a pleural effusion
Transudate - low protein
Modified transudate = higher prtein
Exudate - puss and gross stuff - can be non-septic, septic, blood or chyle
What is the most common cause of modified transudate fluid in plural effusion
Increased hydrostatic pressure secondary to high sided heart failure
What causes non-septic (exudate) fusions
FIP, neoplasia, fungal infection
(no bacteria, lots of neutrophils)
What causes septic (exudate) effusions - aka pyothorax
Penetrating chest wound
FB inhalation
Ruptured oesophagus
Tumour
What causes chylothorax
Disruptions of the thoracic duct
e.g. cranial VC obstruction, neoplasia, trauma to thoracic duct
What causes a haemothorax
Trauma, coagulopathy, neoplasia, lung lobe torsion
List the diagnostic methods for pleural effusions
Based on clinical findings
Imaging e.g. radiography/Ultrasound
Thoracocentesis and look at the fluid
What is the most common cause of spontaneous pneumothorax
Ruptured pulmonary bulla or sub-pleural bleb
Describe the management of spontaneous pneumothorax
Medical management to stabilise
Lobectomy if needed
List 4 causes of mediastinal disease
Benign or malignant tumours
Cystic lesions
Enlarged mediastinal lymph nodes
Haematomas
What is a common sign of mediastinal disease on a radiograph
Displaced trachea
Clinical signs of mediastinal lymphoma
Tachypnoea, inspiratory hyperpnoea, dull heart sounds, pleural effusion
Non compressible anterior mediastinum
