Respiratory Pleural Space Disease Flashcards
1
Q
What types of tissues does the pleura contain?
A
- Mesothelial cells
- Elastic fibers
- Smooth muscle fibers
- Lymphatics, arteries, veins, and capilaries
2
Q
What is the Basic physiology of the pleural space?
A
- Starling’s Laws
- Fluid leaves from systemic circulation, crosses the parietal pleura into the pleural space
- Reabsorbed by visceral pleura
- pulmonic circulation-venous caps
- Parietal pleura lymphatics also reabsorb fluid
3
Q
How do pleural effusions occur?
A
- Increased Capillary Pressure (hydrostatic)
- High pressure from heart failure or venous obstruction
- Decreased Plasma Proteins (oncotic)
- Liver disease, Protein loss (Kidney/GI), cutaneous loss, severe malnutrition
- Increased Capillary Permeability (leakage)
- sepsis, neoplasia, infections, immune-mediated diseases
- Blockage of Lymph Return (obstruction)
- True obstruction (neoplasia, granuloma, thrombus, heartworms)
- Relative/Functional (right heart failure or increased lymph production)
4
Q
What are the types of Pleural Space Disease?
A
- Pneumothorax - air in pleural space
- Pleural effusion - fluid in pleural space
5
Q
What are causes of Pneumothorax?
A
- Trauma
- closed-blunt trauma (lung leaking)
- Open-penetrating trauma (external environment air)
- Tension Pneumothorax
- the ‘hole’ acts as a one-way valve, allowing air to enter on inspiration but not leave on expiration
- Shifts hear and vessels resulting in compression, shock, and hypoxia
- Spontaneous
- Abscess, bullae, neoplasia, foreign body, parasites
- Iatrogenic
- Lung aspirate, chest tube placement, anesthesia, ventilation
6
Q
What is the pathophysiology of a pneumothorax?
A
- Air/fluid in pleural space causes lung collapse (atelectasis)
- ⇣ Tidal volume
- Hypoxemia
- ⇡ respiratory rate
- ⇡ pressure in pleural space cause ⇣ venous return to the heart
- ⇡HR to maintain cardiac output
7
Q
What are the clinical signs of penumothorax?
A
- Variable respiratory distress
- Tachypnea, dyspnea, cyanosis, abdominal breathing
- Decreased lung sounds
- Initially decreased in dorsal fields
- As more air leaks in, sounds decrease everywhere
8
Q
What is a Bulla?
A
- “Bleb”
- Air-filled spaces in the lung parenchyma due to rupture of alveolar walls
- More in large, deep-chested dogs
9
Q
What is the treatment for pneumothorax?
A
- Oxygen and Low stress
- Thoracocentesis
- Repeat radiographs to look for underlying disease
- Repeat thoracocentesis if air returns and dyspneic
- consider chest tubes w/ recurrent air buildup (3Taps then tube)
- If traumatic provide analgesia and address other injuries
10
Q
What are the indications for a thoracocentesis?
A
- Diagnostic
- Therapeutic
11
Q
How is a thoracocentesis performed? What equipment is used?
A
- Clip and scrub 6-8th intercostal space
- Xray/US to pick best one
- Ventral for fluid
- Dorsal for air
- Patient in sternal recumbency
- Insert needle cranial to rib
- Remove as much air/fluid as possible
- Purple/Red top tubes for Dx
- Repeat on other side as needed
- Sterile gloves, clipper, prep
- Butterfly/needle/catheter
- Extension set
- 3-way stop cock
- 60ml syringe
- Bowl for fluid, Red and Purple top tube
12
Q
What are the complications that can occur with a thoracocentesis?
A
- Lung laceration and pneumothorax
- hemorrhage
- cardiac irritation/arrhythmia
- introduce infection
13
Q
What are the indications of chest tubes?
A
When air/fluid continues to build up despite repeated taps
14
Q
When should a chest tube be removed?
A
When <2-3ml/kg fluid in 24 hrs
15
Q
What are the different types of effusions?
A
- Exudate
- Chylus
- Transudate
- Hemorrhagic
16
Q
What is exudative fluid?
A
- Cloudy fluid, color varies
- Septic or nonseptic
- High cellularity
- mostly neutrophils and macrophages
- look for intracellular bacteria
- look for neoplastic cells
- Caused by:
- infection
- neoplasia
17
Q
What is Chylus effusion?
A
- Chylus fluid
- Milky color from chylomicrons
- moderate cellularity
- Many small lymphocytes
- Triglycerides in fluid:serum is 2-3:1
- Chylous effusion TG > 100mg/dL
- Causes:
- Cardiomyopathy
- Lymphatic obstruction
- Heartworm disease
- Idiopathic
18
Q
What is Transudate effusion?
A
- Pure:
- Clear or straw-colored
- low cellularity
- from low oncotic pressure
- hypoalbunemia
- liver failure, Renal or GI loss
- Modified
- Moderate cellularity
- from high hydrostatic pressure
- Normal albumin
- Right CHF, Neoplasia
19
Q
What are hemorrhagic effusions?
A
- Hemorrhagic: bloody but low PCV
- Hemothorax: high PCV, almost the same as peripheral blood
- Often see erythrophagocytosis
- Causes:
- Coagulopathies
- Neoplasia
- Trauma
- Lung lobe torsions
20
Q
What is the pathophysiology of a pyothorax?
A
- Bacterial entrance:
- through perforated respiratory tract or esophagus
- inhaled grass awn/foreign body
- Through chest wall - penetrative wounds
- Local (lung abscess) or hematogenous spread
- through perforated respiratory tract or esophagus
- Inflammation increases vascular permeability
- Proteins leak out of vessels
- increases oncotic pull in pleural space, more fluid follows
- Pleura thicken and clog so can’t reabsorb fluid
- Proteins leak out of vessels
21
Q
What are the treatment options for pyothorax?
A
- Medical Management
- ICU car and chest tube for drainage and lavage
- IV fluids and antibiotic therapy
- cytology to help chose pending culture and susceptibility
- Surgical management
- Indications for exploratory thoracotomy
- Suspect foreign body
- no improvement with medical management in 2-3 days
- Indications for exploratory thoracotomy
22
Q
What type of fluid is seen in Feline Infectious Peritonitis (FIP)
A
- Non-septic exudate
- High protein count, lower cellularity
- Mostly non-degenerate neutrophils and macrophages
23
Q
How is FIP diagnosed?
A
- Submit effusion for immunocytochemistry or PCR
- limitations of coronavirus serology (IFA)
24
Q
What are the common neoplastic effusions?
A
- Lymphoma
- Mesothelioma
- Carcinomatosis
- Metastatic neoplasia
- Thymoma
- Primary lung tumor
- Can be exudative, transudate, chylous or hemorrhagic
25
Q
how are Neoplastic effusions diagnosed
A
- Cats with mediastinal lymphoma and effusion
- decreased compressibility of cranial thorax on exam
- can aspirate mass/node with ultrasound guidance
- Radiographs, thoracic ultrasound, CT/MRI
- Cytology of pleural fluid
- Ultrasound-guided aspirates when possible
- Thoracoscopy or thoracotomy
- biopsy the pleura and lungs
26
Q
What is the treatment for neoplastic effusions?
A
- chemotherapy +/- surgery
- consult oncologist
27
Q
What is the common signalment of Chylothorax patients?
A
- More cats than dogs - any breed
- Dogs- Afgans (middle age) & Shiba Inus (<1yo)
- Cats- Siamese and Himalayan (older)
28
Q
What are the clinical signs of chylothorax?
A
- Coughing and dyspnea
- Can be slow onset over months
29
Q
What causes Chylothorax?
A
- Mediastinal lymphoma
- Cardiomyopathy
- Pericardial disease
- Heartworm disease
- Fungal granuloma
- Lung lobe torsion
- Cranial vena cava thrombus
- Lymphangiectasia
- Idiopathic
30
Q
How is Chylothorax diagnosed?
A
- Fluid Analysis and Cytology
- Purple top EDTA tube
- Color varies with fat content and degree of hemorrhage (white to pink)
- small lymphocytes or neutrophils
- Compare triglycerides in fluid:serum
- Red top tube
- Chylous effusion will have 2-3x more triglycerides than serum
- Chylous effusion should have triglycerides >100mg/dL
- Test for heartworm disease
- antigen for dogs
- antigen and antibody for cats
- Echocardiogram
- Thoracic Ultrasound
- helps find mediastinal mass, lymphadenomegaly
- Aspirate if possible
31
Q
What is the treatment for chylothorax
A
- Minimize stress and address primary cause if identified
- If idiopathic:
- Thoracocentesis as needed
- Chest tubes usually not needed
- Low fat diet (⇣ fat in effusion, improves reabsorption)
- Rutin 50-100mg/kg PO TID
- MOA theories: reduces buildup of fluid, improves lymphatic drainage, recruits and stimulates macrophage phagocytosis of chyle
- Thoracocentesis as needed
- Surgical options:
- If known trauma
- If idiopathic and unmanageable medically
- Over time fibrin causes pockets of fluid, challenge to drain
- If tapping more than once weekly
- If tapping does not resolve dyspnea
- Multiple surgical procedures in combo:
- thoracic duct ligation with partial pericardiectomy is an option
- Recommend consultation or referral to a boarded surgeon
32
Q
What are transudates?
A
- Low protein, low to moderate cellularity fluid
- Most macrophages and mesothelial cells, some neutrophils
- look carefully for neoplastic cells
33
Q
What causes Pure transudates?
A
- Decreased Oncotic Pressure (hypoproteinemia)
- Protein losing enteropathy
- protein losing nephropathy
- liver failure
34
Q
What causes modified transudates?
A
- ⇡ Hydrostatic Pressure
- congestive heart failure, thromboembolic disease, neoplasia
- Neoplastic Effusions
- Mesothelioma, lymphoma, thymoma, carcinomatosis
- Vasculitis
- Infection (sepsis, rickettsial, leptospirosis….)
- Immune (lupus, bee stings, snake bites)
- Other inflammatory (pancreatitis)
35
Q
How are transudates diagnosed?
A
- Good history and physical exam
- Minimum Database
- CBC- inflammatory (maybe)
- Chemistry- normal albumin concentration ≠ oncotic problem
- low albumin look for liver, GI, or kidney disease
- UA- proteinuria (maybe)
- Radiographs post-thoracocentesis +/- thoracic ultrasound
- Rule out heart disease with echocardiogram
- Abdominal ultrasound may be helpful
- Assess liver, pancreas, GI, Kidneys, nodes, look for masses
- If not hydrostatic or oncotic, then is vasculitis the cause?
- consider infectious, immune disease
- tick titers (RMSF), ANA, Fundic exam
- consider infectious, immune disease
- Is primary GI causing low protein and fluid buildup?
- can be bicavity effusion
- Requires GI biopsies
36
Q
What is the treatment for transudates?
A
- Minimize stress
- Provide oxygen when needed
- Thoracocentesis as needed
- Tailor treatment to specific underlying disease
37
Q
What are the differentials for Hemothorax/hemorrhagic effusion?
A
- Trauma
- Malignancy
- Coagulopathy
- Lung lobe torsion
- Heartworm disease
- Pulmonary Infarct
- pulmonary abscess
- Recent surgery
38
Q
How is hemothorax/hemorrhagic effusion diagnosed?
A
- Thoracocentesis - avoid if suspected coagulopathy
- Tests may include:
- clotting test
- thoracic radiographs
- ultrasound
- CT
- heartworm
39
Q
What is the treatment for hemothorax/hemorrhagic effusion?
A
- Minor bleeding should reabsorb
- Severe cases may need thoracocentesis and transfusion
- Treat any identified underlying disease
- Ongoing bleeding might require surgical exploratory
40
Q
How is Anticoagulant Rodenticide Toxicity diagnosed and treated?
A
- Dx based on history and ⇡ coagulation times
- PT will be elevated first
- can test for rodenticide to confirm
- Treatment
- induce emesis w/in 2-3hrs of ingestion
- Vit K1 supplementation for 4 weeks
- Remove exposure
- keep safe from trauma
- Monitor respirations
40
Q
How is Anticoagulant Rodenticide Toxicity diagnosed and treated?
A
- Dx based on history and ⇡ coagulation times
- PT will be elevated first
- can test for rodenticide to confirm
- Treatment
- induce emesis w/in 2-3hrs of ingestion
- Vit K1 supplementation for 4 weeks
- Remove exposure
- keep safe from trauma
- Monitor respirations
