Pleural Space Disease Flashcards
define pleura
pair of serous membranes (mesothelial cells) lining the thorax and lungs
can be divided based on anatomy:
-parietal: costal (on ribs), mediastinal (incomplete/fenestrated; what happens on one side happens on the other side too), and diaphragmatic
-visceral: pulmonary
describe the pleural space
- a potential space:
-0.1 ml/kg pleural fluid in dogs
-0.3ml/kg pleural fluid in cats - function of fluid is to reduce friction during respiration
describe clinical signs of pleural space disease
- mild to severe:
-orthopnea
-dyspnea
-cyanosis - rapid, shallow breathing: decreased lung expansion causes reduced tidal volume
-restrictive breathing pattern
there is something in the pleural space other than that tiny amount of fluid!!
describe PE of pleural space disease
- dull or quiet heart and lung sounds
-depends on where the pathology is located in the pleural space
-fluid goes ventral, so dull ventrally
-air rises so dull dorsally - increased respiratory rate/effort
describe differentials for fluid or soft tissue pleural space disease
fluid:
-transudate
-modified transudate
-exudate
soft tissue:
-diaphragmatic hernia
-mass: neoplasia vs. granuloma vs. abscess
describe pneumothorax
3 types:
- traumatic:
-penetrating
-blunt: transient increase in airway pressure and rupture of alveoli (pressure transmitted from outside through lungs, see with HBC, falls, dog fights, kicks) - spontaneous:
-primary: pulmonary blebs or bullae (dogs) will eventually pop and cause a continuous pneumothorax by continuing to leak
-secondary: neoplasia, abscesses, bacterial, parasitic, or fungal pneumonia (dogs), lower airway disease, neoplasia (cats) - iatrogenic:
-needle or scalpel
-barotrauma
-traumatic intubation
-feeding tube misplacement
when in doubt on rads, try to follow pulmonary vessels, should NOT be able to trace all the way to the body wall if there is air in the pleural space
describe glide sign
- a NORMAL finding on thoracic ultrasound when the visceral and parietal pleura make contact during each respiration
- LACK of a glide sign is suggestive of a pneumothorax
describe treatment of pneumothorax
- thoracocentesis: in emergency setting
-can be diagnostic! if look like going to die, DONT take to rads, do a dx thoracocentesis (3cc syringe); if lose negative pressure = full of air
-if don’t lose negative pressure, probs in lung so back needle on out - thoracostomy tube: for animals with spontaneous pneumos that need constant suction
- continuous suction
- blood pleurodesis: try before euth if not money for surgery, not a lot of evidence for efficacy yet
-place a sample line in jug, pull out 5-10ml/kg of blood, squirt into chest tube and hope it clots on top of the leak - lung lobectomy
describe pleural effusion mechanism of formation
recall starling’s forces
promoted by:
- increase in capillary hydrostatic pressure: transudate or modified transudate
- decrease in capillary colloid osmotic pressure: transudate or modified transudate
- increase in permeability of capillary wall: exudate
- obstruction or disruption of lymphatic drainage
describe diagnostics for pleural effusion
- assessment of oxygenation: but if working hard to breathe, still treat them the same!
-so always give oxygen supplementation and anxiolysis!!!! (butorphenol is the safest to give) - imaging:
-thoracic radiographs: soft tissue opacity on lateral, scalloped lung margin
-TFAST: easiest and more helpful than rads for pleural effusion, can do bedside, put probe in multiple spots to look for effusion; heart floating and beating in a pool of black = fluid
-echocardiogram
- clinical pathology: GET THE FLUID FIRST, then look at it!!!! (treat pus if you find a neutrophil!!)
-TP or TNCC: can help you tell pure transudate, modified transudate, or exudate
-NT-proBNP
-cytology
-culture
-PCV if fluid looks bloody
describe pure transudate/hydrothorax
low protein, low cell count effusion
due to:
1. decreased oncotic pressure
-hypoalbunemia is the most common cause of pure transudate pleural effusion!!!
- increased hydrostatic pressure: usually cardiogenic causes
less common for pleural effusion!
describe modified transudate
mod protein mod cell count effusion
due to:
- increased post-hepatic hydrostatic pressure: due to heart failure
- increased vascular permeability:
-vasculitis
-lung lobe torsion
-diaphragmatic hernia - chronic effusions
-pleural irritation can cause increased cell count
-water can be reabsorbed in excess of proteins
describe causes of exudates
high protein high ell count effusion!
- feline infectious peritonitis
- neoplastic effusions
- pyothorax
- bilothorax
- hemothorax
- chylothorax
describe FIP
- coronavirus
- aseptic exudative effusion
- effusion usually present in more acute disease, but may be present terminally in non-effusive cats
- pathophysiology:
-infected macrophages deposited adjacent to small venules, forms pyogranulomas in affected tissues, then inflammatory response can cause vasculopathy and effusion accumulates in body cavities - diagnosis:
-pleural or peritoneal effusion: viscous, straw colored, high protein (>3.5gm/dl), low NCC
-high serum antibody test
-RT-PCR on effusion
-IHC cells from effusion
-rivalta test
describe neoplastic effusions
- transudates
- exudates
- hemothorax
pathogenesis: depends!
-increased vascular permeability
-tumor shedding or shedding of necrotic material or
-lymphatic obstruction
