pleural & chest wall diseases Flashcards
what are the key characteristics of the pleura?
- 0.3-0.5mm thick
- pleural fluid forms a <1mm film
- pH is around 7.6
what is the pleura?
a thin tissue covered by a layer of cells (mesothelial cells) that surrounds the lungs and lines the inside of the chest wall
what are the 2 layers of the pleura?
- parietal pleura
- visceral pleura
these are both completely separate
what are the key characteristics of the pleural space?
- normally at negative pressure which keeps the lungs inflated
- only has a few mls of fluid which helps lubricate the normal movement of the lungs during breathing
what is contained in the pleural fluid?
- protein
- lymphocytes
- macrophages
- mesothelial cells
what is a pleural effusion?
fluid in the pleural space
what is a pneumothorax?
air in the pleural space
what are the presenting features of a pneumothorax?
- breathless
- chest pain
- cough
- features within the history
- raised respiratory rate, may have low oxygen saturation
- if unwell tension pneumothorax may be very unwell/peri arrest
- on examination: reduced breath sounds, increased percussion note, reduced expansion, tracheal deviation
- abnormal CXR
what happens with a pneumothorax?
- air in pleural space
- entry of air creates positive pressure leading to collapse of lung
- tension pneumothorax leads to ‘one way valve’
- primary/secondary/traumatic/latrogenic
what are the features of a primary pneumothorax?
- spontaneous
- occurs in healthy young tall males
- apical bleb
- more common in smokers (especially cannabis smoking)
- tension: rarely occurs
- managed according to the size and symptoms of the patient
- won’t always need a drain or admission
what are the features of a secondary pneumothorax?
- background of known lung disease
- most likely need a drain
- tension more common
what is the follow up like of a primary pneumothorax?
- 54% recurrence in the first 4 years
- 20-30% recurrence in the first 2 years
- recurrent primary: surgical/medical thoracoscopy and pleurodesis
what is the follow up like of a secondary pneumothorax?
attempt pleurodesis after the first episode as the recurrence rate is high
what is the advice for a pneumothorax?
- no deep sea diving ever (as sudden change in pressure risk is higher)
- normal swimming and diving to less than 10 depth is fine
- air travel: one week after full re-expansion of the lung
- coast guards, naval officers, air force etc need to change jobs
- high altitude sports and travel should be done with caution and should be discourages
stop smoking
what happens with a pleural effusion?
- small volume of lubricating fluid is maintained via a delicate balance of hydrostatic oncotic pressure and lymphatic drainage
- disturbances in any of these mechanisms may lead to pathology and cause pleural effusion
what are the clinical features of a pleural effusion?
- shortness of breath
- cough
- pleuritic chest pain
- reduced breath sounds
- ‘dull’ to percussion on examination
what are the causes of pleural effusion?
- altered permeability of the pleural membranes
- reduced oncotic pressure (low albumin)
- increased capillary hydrostatic pressure
- decreases lymphatic drainage or blockage
- increased peritoneal fluid
- most common cause are heart failure, pneumonia and malignancy
what are the infections make pleural effusion more likely?
- bacterial
- TB
- fungal
- viral
what benign causes make pleural effusion more likely?
- high oncotic pressure: heart failure, fluid overload
- low protein state: nephrotic syndrome, protein losing enteropathy, chronic liver disease
- autoimmune disease: rheumatoid arthritis, SLE
- reactive: PE, dressers syndrome
what malignant causes make pleural effusion more likely?
- primary: mesothelioma
- secondary: most common = primary lung, breast, gynaecological, haematological, renal, GI tract
what are the risk factors of pleural infection?
- diabetes
- immunosuppression
- alcohol, IVDU
- poor oral hygiene and aspiration (anaerobic)
- latrogenic
- trauma
- recent hospitalisation
what are the predictors for the worse outcome of pleural infection?
- pH <7.2 high LDH
- low glucose (<2/3rd serum glucose)
- positive culture
- loculations (seen on ultrasound or CT)
what is the spectrum of parapneumonic effusions?
uncomplicated parapneumonic effusion
- resolve on treatment of underlying pneumonia, may not need to be drained
complicated parapneumonic effusion
- bacterial invasion into the pleural space
- fibrin deposition may form locules/septations
- patient will likely need a drain
empyema
- Frank pus within the pleural cavity
- may organise with thickening of the pleural surface preventing lung re-expansion and impairing lung function
what are the principles of care with pleural infection?
- accurate diagnosis
- control infection: choosing correct antibiotics
- drainage of infection material: chest drain, management of the chest drain is key, aim is to remove infection form pleural space so avoid blockages
what are the features of malignant effusion?
- high recurrence rate
- medial life expectancy due to any cause: 6 months
- significant impact on quality of life: last few weeks of life
- impact on wider healthy economy: average LOS 4 to 6 days
- mostly unilateral
- massive unilateral effusion are usually not benign
what are the symptoms of malignant effusion?
- often present with breathlessness
- cough
- hypoxia
- mostly are hemorrhagic
how do you manage malignant pleural effusion?
- minimally invasive and reduced number of interventions
- options available: aspiration >90% recurrence rate, chest drain +/- pleurodesis 60-70% success, indwelling pleural catheter, thoracoscopic drainage + pleurodesis
what are the benefits of drainage of effusion in dwelling pleural catheter?
- avoids patient admission to hospital
- suitable for long term drainage
- improves quality of life
- 50% spontaneous pleurodesis
what is talc pleurodesis for pleural effusions (without infection)?
- to prevent recurrence
- mediated talc
- creates a talc slurry to tick the pleura together
- works in about 70%
- lung needs to be reinforced and output <200ml/24hr
- drainage can’t be blocked: drain needs to be fall out
- pain, fever
what are the characteristics of a haemothorax?
- not a blood effusion
- traumatic
- latrogenic
- aortic dissection
- depending on cause: resuscitate, urgent drainage, consider VATS
