Pleural Effusion And Pneumothorax Flashcards
What is the most common cause of pleural effusion?
1) Cardiac failure
2) pneumonia
3) malignancy
4) pulmonary embolism due to ischaemia from the release of vasoactive cytokines that cause pleural effusion
Malignancy causes cancer cells to spread to the pleural space, increasing pleural fluid production
Where is pleural fluid derived from?
Pleural fluid is typically derived from blood vessels of the parietal pleural surfaces. Fluid accumulation in the pleural space can compress the lungs and reduce the ability to expand. The parietal pleura contains sensory nerve fibres for pain perception.
What is pleural effusion?
Accumulation of fluid in the pleural space that can compress the lungs and reduce their ability to expand
What are the main causes of pleural fluid accumulation?
- Increased pulmonary capillary pressure
- Increased pulmonary capillary permeability assoicated with infection like pneumonia
- Obstruction of pleural lymphatic drainage
- Fluid migration from other sites
- Rupture of thoracic vessels, leading to haemothorax or chylothorax
Includes conditions like pneumonia and malignancies
What does pleural fluid rich in lymphocytes indicate?
malignancy or tuberculosis.
What is chylothorax?
Abnormal accumulation of chyle, a lipid-rich lymph, in the pleural space surrounding the lung. It causes pleural fluid to appear turbid, milky, serous or blood-stained and presence of high triglyceride level. It typically occurs with malignancy assoicated with lymphoma, trauma or following thoactomy.
This typically occurs due to congenital lymphatic abnormalities, malignancies of the lung, lymphoma or oesophageal and complication of tuberculosis.
What are the symptoms of pleural effusion?
- Pleuritic chest pain, sharp severe localised pain worsened with breathing or coughing
- Fever
- Dyspnoea
- Cough
- Reduced tactile vocal fremitus
- Dullness to percussion
- Reduced vesicular sound
What is a marker for lung injury?
LDH, WBCs, and protein
What are the primary forms of pleural effusion based on fluid composition?
- Transudative effusion
- Exudative effusion
What characterizes transudative effusion?
Results from conditions affecting hydrostatic/oncotic pressures, leading to fluid extravasation and composition is high in water.
Conditions where there is reduced production of albumin.
Which conditions cause transexudative pleural effusion?
Pressure gradient disruption: right heart overload, left heart failure, pulmonary embolism
Low albumin: liver cirrhosis, nephrotic syndrome, peritoneal dialysis or atelectasis
What characterizes exudative effusion?
Caused by increased capillary permeability, typically due to inflammation and high amounts of inflammatory cytokines
What is the most common cause of exudative effusion in younger patients?
parapneumonic effusion
What are the common causes of exudative effusion?
- Parapneumonic effusion
- Tuberculosis
- Pulmonary embolism
- Rheumatoid arthritis
- Malignancy
- Infection such as pneumonia or tuberculosis
What are the less common causes of exudative effusion?
-> trauma from haemorrhoid
->Thoracic duct injury assoicated with chylothorax
->drugs such as methotrexate, amiodarone, phenytoin and dasatinib
What is a parapneumonic effusion?
There is exudative effusion rich in protein which becomes complicated when bacteria infiltrate and WBCs and glucose increase progresses to Empyema: pus-filled pocket in the pleural space, characterised by high WBC count and fever and features of sepsis. It is assoicated with low pleural pH.
What is empyema?
Pus-filled pocket in the pleural space characterized by high WBC count and fever
What are the complications with pleural effusion?
Pleural fluid accumulating, creating pressure that makes a V/Q mismatch where ventilation is lowered and results in type 1 respiratory failure, especially with atelectasis
Parapneumonic effusion
Empyema: pus-filled pocket in the pleural space, characterised by high WBC count and fever and features of sepsis. It is assoicated with low pleural pH.
What does Light’s criteria assess for?
Exudative effusion based on:
* Pleural protein ratio over 0.5
* Pleural LDH ratio over 0.6
* Pleural LDH greater than 2/
May not be accurate with heart failure for those on diuretics
What indicates a complicated parapneumonic effusion or empyema?
Pleural pH less than 7.2, low pleural glucose levels, and low pleural WBC count
What does milky pleural fluid typically indicate?
Chylothorax
What are the investigations for pleural effusion?
FBC with U&Es, lLFTs, albumin, lipase enzyme, amylase and cardiac enzyme levels
Sputum culture, acid fast smear for mycobacterium tuberculosis
CXR
Echocardiogram to rule out heart failur -> if present, start on diuretics
Thoracentesis to assess the pleural fluid
What does clear pleural effusion indicate?
clear fluid indicates absence of pleural protein and LDH, indicating transudative effusion, therefore from CHF, Liver cirrhosis or nephritic syndrome.
What does cloudy fluid in pleural effusions indicate?
cloudy fluid indicates exudative effusion rich in proteins and LDH, indicating exudative effusion from lung injury.
What do triglycerides in pleural fluid indicate?
chylothorax
What does pleural amylase in pleural fluid indicate?
pancreatitis or oesophageal rupture
What does low pleural glucose indicate?
empyema or parapneumonic effusion
What does viscous pleural fluid indicate?
mesothelioma
What does black pleural fluid indicate?
aspergillosis infection
What is the test for autoimmune cause of pleural effusion?
ANA/Rheumatoid factor positive
What is the test for tuberculosis in pleural fluid?
tuberculosis
What is the treatment for heart failure-related pleural effusion?
No pleural tap unless atypical features present with presentwith bilateral effusion or they fail to resolve within 3 days following diuretics therapy.
What is the treatment for parapneumonic effusion or empyema?
Chest tube drainage with needle aspiration and antibiotic treatment
What is reccomended for recurrent malignant pleural effusion?
indwelling pleural catheter
What is the treatment for refractory malignant effusion?
pleurodesis to reduce the pleural space
What characterizes pneumothorax?
Pleuritic chest pain localized and worse on inspiration, dyspnoea, increased tactile fremitus, and decreased breath sounds
How is pneumothorax classified?
Pneumothorax is classified by the British thoracic society based on the depth from the chest wall to the outer pulmoanry edge. A small pneumothorax is less than 2cm and a large pneumothorax is over 2cm. A patient is considered clinically stable in the absence of respiratory disturbance, thoracic CT is reccomended for identifying spontaneous pneumothorax.
What is primary spontaneous pneumothorax associated with?
Tall, thin males aged 10-30 years, and conditions like Ehlers-Danlos syndrome or Marfan’s syndrome
What is the pathophysiology of primary pneumothorax?
It is characterised by the formation of subpleural apical blebs, where pockets of air called bullae are found at the apex between the lung tissue and pleura that can rupture and allow air to enter the pleural space. For asymptomatic patients, observation is required for a small pneumothorax.
This can be congenital where the upper pulmonary lobe develops faster than the vasuclature which causes a lack of blood supply. Alternatively tall individuals have more negative apical lung pressure and a over alveolar pressure that can led to bullae formation
What is secondary spontaneous pneumothorax associated with?
Rupture of damaged pulmonary tissue, associated with Underlying lung conditions that predispose patinets to hyperinflation and the formation of bullae air pockets that can rupture and allow air to enter into the airspace -> more common in emphysema within COPD, severe asthma
Lung necrosis due to infection or malignancy
What is traumatic pneumothorax?
Traumatic pneumothorax typically occurs due to a needle aspiration from thoracentesis, lung biopsy, mechanical ventilation (due to positive pressure pneumothorax) or central lines, associated with cardiopulmonary function becoming unstable foll?owing the procedure.
What are the complications with spontaneous pneumothorax?
Type 1 Respiratory failure due to V/Q mismatch-> more common in secondary pneumothorax and may result in a pulmonary shunt
Increase in pressure due to air in the pleural space resulting in atelectasis
Tension pneumothorax
What is tension pneumothorax?
A condition where air enters the pleural cavity but cannot escape, increasing pleural pressure and therefore pleural cavity pressure increases and is compressing on structures on the mediastinum like the diaphragm and right side of the heart. It resuts in reducing diastolic filling, raised JVP, reduction in cardiac output and causes tracheal deviation away. There wil be reduced breath sounds and cause the affected lung to collapse and contralteral lung and heart to be pressurised, leading to severe dyspnoea, cyanosis and hypotension
What is the pressure gradient in the pleural pressure?
Pleural pressure is typically negative compared to atmospheric pressure during respiration and the pressure difference between pulmonary alveoli and pleural cavity is trans pulmonary pressure, which enables for lung elastic recoil.
In pneumothorax, the air cavity is connected to the pleural cavity so air from the alvoeli migrates to the pleural cavity until the pressures of both are equal. There is a reduction in transpulmonary pressure and the vital capacity due to reduced ability of the lung to expand during inspiration. there is reduced arterial oxygen
What is the recommended treatment for tension pneumothorax?
Immediate chest decompression
How is pneumothorax diagnosed?
cxr shows absence of lung markings
High resolution CT shows presence of bullae
What is the treatment for primary pneumothorax?
Percutaneous simple needle aspiration for all patients requiring interveniton and progression to chest ctube when simple aspiration has failed
What is the treatment of secondary pneumthorax?
Percutaneous simple needle aspiration for small pneumothorax even with mild pneumothorax and progression to chest tube except for patients with small pneumothorax and no respiratory symptoms
How is a small pneumothorax treated?
Less than 2cm is with watchful waiting in hospital, serial CXR to assess for progression of pneumothorax andwh oxygen saturation
How is a large pneumothorax treated?
Larger than 2cm and tension pneumothorax is treated with chest decmpression
Ideally, needledecompression should be performed for tension pneumothorax, a life-saving emergency procedure where a vanilla is placed into the chest to decompress to alleviate symptoms and prevent further clinical deterioration. It should be avoided for simple pneumothorax
What does a chest tube do?
Evacuates air or fluid from the pleural cavity and restores negative intra-thoracic pressure. There is a collection bottle from the patient via thoracentesis, water seal chamber where air bubbles indicate presence of pneumothorax or device abnormalities. There should be tidaling, where fluid moves up and down which is normal with breathing cycle. It is used to evacuate air from the pleural cavity and restore negative intrahtoracic pressure to promote lung expansion. It shold only be removed once CXR shows evidence of lung re-expansion.
What is an indication for thoracic surgery?
Chest tube Air leaks beyond 2 days or failure of lung-expansion is an indication for thoracic surger y
What does thoracic surgery include?
Thoracic surgery includes parietal pleurectomy , where parietal pleural is removed from the chest wall and pleurodesis, but is an alternative option when chest tube failure or needle aspiration has occurred.
It is not reccomended for use in suction due to risk of pulmoanry oedema following re-expansion
What is the significance of pleural fluid amylase levels?
Indicates pancreatitis or oesophageal rupture
What is the typical management for traumatic pneumothorax?
Percutaneous simple needle aspiration or chest tube insertion depending on severity
What is the effect of pneumothorax on transpulmonary pressure?
Reduces transpulmonary pressure leading to decreased vital capacity
What does the presence of loculations in pleural fluid indicate?
Risk of empyema
What is the initial diagnostic imaging for pneumothorax?
CXR (Chest X-Ray)
What is the treatment for a small pneumothorax?
Watchful waiting and serial CXR
What should be avoided in simple pneumothorax treatment?
Needle decompression
