Pleural Space Disease Flashcards
What is the pleura?
Inner wall of body cavities lined by single layer of mesothelial cells
Visceral pleura - pulmonary side
Parietal pleura - medasinal, diaphragmatic, costal
Contains rich lymphatic system which drains pleural cavity
0.1ml/kg of fluid to allow smooth movement of lungs in breathing
Has negative pressure so fluid wants to pool
Mediastinum
Space between left and right pleural sacs
Contains heart and major vessels
What is pleural space disease?
Accumulation of fluid, air or soft tissue mass
Severity depends on amount
Causes direct compression of lungs and leads to negative pressure loss (lungs collapse)
Clinical signs of pleural space disease
Short, shallow breathing
Tachypnoea
Open mouth breathing
Orthopnoea - using body to breathe
Cyanosis if severe
What is pleural effusion?
Fluid in pleural space surrounding lungs
Types of pleural effusion
Transudate (low protein, low cellularity
Modified transudate (high protein, moderate cellularity )
Exudate (High cellularity and variable protein)
Reasons for pleural effusion
Increased fluid formation
Decreased fluid absorption
Causes of Increased fluid formation
‘leaky’ capillaries - Pleural inflammation
Increased IV pressure - CHF
Increased lung interstitial fluid - CHF
Decreased pleural pressure
Increase in pleural fluid protein
Disruption of thoracic duct or blood vessels
Causes of decreased fluid absorption
Obstruction of lymphatic drainage
Increased systemic vascular resistance (RSHF)
Reduced vascular oncotic pressure (hypoalbuminaemia)
Causes of transudate pleural effusion
Protein losing enteropathy
Losing protein from guts/kidneys
Liver problems
Insufficient dietary protein
Causes of modified transudate
Increased hydrostatic pressure secondary to right sided heart failure
Forcing blood through capillaries with high pressure
* Pericardial disease
* Cardiomyopathy
* Pulmonary hypertension
* Pulmonic stenosis
Diaphragmatic hernia
lung lobe torsion
Causes of non-septic exudate effusion
FIP
Neoplasia
Chronic chylothorax
Chronic lung lobe torsion
Fungal infection
Causes of septic exudate effusion
Penetrating wound
Foreign body inhalation
Ruptured oesophagus
Haematogenous bacterial spread
Causes of chylothorax
Disruption of thoracic duct
* neoplasia
* Heart disease
* Fungal infection
* Diaphragmatic hernia
Causes of haemothorax
Trauma
Coagulopathy
Neoplasia
Lung lob torsion
Initial management for patient with suspected pleural effusion
Oxygen supplementation and careful monitoring
Emergency thoracic ultrasound
NO RADIOGRAPHS IF SEVERELY DYSPNOEIC
Thoracocentesis to stabilise for further investigation
Thoracocentesis
Local anaesthetic can be used
Clip and surgical scrub of area
Use butterfly needle/catheter at ICS 6-8
Slight negative pressure on insertion
Use 3 way stopcock
Aseptic technique
Indications for using a chest drain
If multiple thoracocentesis will be required
Large volumes of effusion
Pneumothorax
Chest wall injuries
Bite wounds
Pyothorax
What is Pneumothorax
Air in pleural space
Causes of pneumothorax
Rupture of major airways/lung parenchyma
Thoracic trauma (broken rib)
Perforation of oesophagus
Iatrogenic - ventilation under GA
Clinical signs of pneumothorax
○ Restricting breathing pattern
Short, shallow breaths
○ Auscultation reveals dull lung sounds dorsally and increased ventrally
Opposite of pleural effusion
○ Percussion
Increased resonance
Treatment for pneumothorax
○ Oxygen
○ Drain pneumothorax as necessary
○ Approx. 90% recovery with strict cage rest for up to 2 weeks
Inappropriate for some animals - welfare issue???
○ Some require chest drains and Heimlich valve
Allows air to exit but not enter
○ Surgical exploration/correction at referral level
○ If open wounds use sterile dressings
