pleural and chest wall disease

Question 1

what happens during inhalation

Answer 1

scalene muscles elevate 1st and 2nd ribs
inferior part of sternum moves anteriorly
external intercostal muscles elevate ribs
diaphragm moves inferiorly during contraction

Question 2

what can result in altered respiratory mechanics

Answer 2

Chest wall (kyphoscoliosis)
Respiratory muscle weakness

Question 3

what are the types of pleura

Answer 3

visceral and parietal

costal, mediastinal, costomediastinal

Question 4

what does the pleura do

Answer 4

Thin tissue covered by a layer of cells (mesothelial) that surrounds the lungs and lines the inside of the chest wall
Two sides are completely separate
Pleural space is normally at negative (subatmospheric) pressure (keep lungs inflated)

Question 5

what is pleural fluid

Answer 5

Normal pleural space has only a few mls of fluid (lubricate lungs in normal breathing)
Pleura is 0.3-0.5 mm thick
Pleural fluid forms <1mm film
Fluid contains protein and small numbers of cells
Lymphocytes, macrophages, mesothelial cells
pH. 7.6

Question 6

what happens if fluid or air moves into the pleural space

Answer 6

effusion or pneumothorax

accumulation of positive pressure – lung collapse

Question 7

what are common pleural conditions

Answer 7

pneumothorax
pleural effusion
pleural infection/empyema
malignant pleural effusion
heart failure
haemothorax

Question 8

how do pleural conditions present

Answer 8

breathlessness
chest pain
cough
features in history
raised respiratory rate, may have low oxygen sats
if unwell with tension pneumothorax – may be very unwell/peri arrest
on examination: reduced breath sounds, increased percussion note, reduced expansion, tracheal deviation
abnormal CXR

Question 9

what is a pneumothorax

Answer 9

air in pleural space
entry of air – positive pressure – lung collapse
tension pneumothorax – one way valve
primary/secondary/traumatic/iatrogenic (caused by treatment)

Question 10

how do primary spontaneous pneumothorax’s occur

Answer 10

Occurs in healthy young tall males 
Apical bleb
More common in smokers (esp cannabis)
Tension rarely occurs
Managed according to size and symptoms – won’t always need a drain or admission

Question 11

how do secondary pneumothorax’s occur

Answer 11

Background of known lung disease eg COPD, bronchiectasis, ILD etc
Mostly will need drain
Tension more common

Question 12

how are primary and secondary pneumothorax’s followed up

Answer 12

Primary
54% recurrence in first 4 years
20-30% recurrence in first 2 years – cont smoking
Recurrent primary – surgical/medical thoracoscopy and pleurodesis

Secondary
Attempt pleurodesis after the first episode as recurrence rate is high

Question 13

what is advised post pneumothorax

Answer 13

No deep sea diving ever (sudden change in pressure risk)
Normal swimming and diving to less than 10 feet depth is fine
Air travel – one week after full re-expansion
Coast guards, naval officers, air force will need to change jobs
High altitude sports and travel should be done with caution/discouraged
Stop smoking

Question 14

what is a pleural effusion

Answer 14

Small vol of lubricating fluid is maintained via a delicate balance of hydrostatic and oncotic pressure, and lymphatic drainage
Disturbances in any of these mechanisms can cause pleural effusion

Question 15

what are the clinical features of pleural effusion

Answer 15

SOB, cough, pleuritic chest pain, reduced breath sounds, dull to percuss

Question 16

what are the causes of pleural effusion

Answer 16

Acute vs chronic, benign vs malignant
Altered permeability of pleural membranes eg infection, inflammation, cancer
Reduced oncotic pressure (low albumin) eg renal disease, liver cirrhosis
Increased capillary hydrostatic pressure ef HF
Decreased lymphatic drainage or blockage eg malignancy, trauma
Increased peritoneal fluid eg liver cirrhosis, peritoneal dialysis

Question 17

what are the commonest causes of pleural effusion

Answer 17

HF, pneumonia and malignancy

Question 18

what are some infections that can cause pleural effusions

Answer 18

bacterial, TB, fungal, viral

Question 19

what are some benign causes of pleural effusion

Answer 19

high oncotic pressure (HF, fluid overload), low protein state (nephrotic syndrome, protein losing enteropathy, chronic liver disease), AI (rheumatoid arthritis, SLE), reactive (PE, dresslers syndrome)

Question 20

what are some malignant causes of pleural effusion

Answer 20

primary (mesothelioma), secondary (most common – primary lung, breast, gynaecological, haematological, renal, GI tract)

Question 21

what is pleural infection

Answer 21

Common – many due to pneumonia (high risk, increased mortality)
Prolonged hospital admission

Question 22

what are risk factors for pleural infection

Answer 22

Diabetes
Immunosuppression (steroids)
Alcohol, IVDU
Poor oral hygiene and aspiration (anaerobic)
Iatrogenic eg previous pleural procedure
Trauma
Recent hospitalisation

Question 23

how is pleural infection diagnosed

Answer 23

Pleural effusion seen on CXR with systemic features of infection such as fever, raised CRP/WCC suggest infection
Take pleural fluid sample
Predictors of worst outcome – pH <7.2 high LDH, low glucose (<2/3 of serum glucose), positive culture, loculations (seen on ultrasound or CT)

Question 24

what is the spectrum of parapneumonic effusions

Answer 24

Uncomplicated – resolve on treatment of underlying pneumonia, may not need to be drained
Complicated – bacterial invasion into pleural space, fibrin deposition may form locules/septations, patients will likely need a drain
Empyema – frank pus in pleural cavity, may organise with thickening of pleural surface preventing lung re expansion and impairing function

Question 25

what are the principles of care for pleural effusions/infections

Answer 25

Accurate diagnosis
Control infection – choose correct antibiotics
Drainage of infected material – chest drain, U/S, consent, safe to do so
Management of chest drain key – remove infection from pleural space so avoid blockages

Question 26

what is malignant effusion

Answer 26

High recurrence rate
Median life expectancy for malignant effusion of any cause – 6 months
Significant impact on quality of life – last few weeks of life
Impact on wider health economy – average LOS 4 to 6 days

Question 27

what is a malignancy effusion

Answer 27

Mostly unilateral
Massive are not usually benign
SOB, cough, hypoxia, mostly they are haemorrhagic

Question 28

how are malignancy effusions managed

Answer 28

Minimally invasive and reduced umber of interventions
Options available
Aspiration >90% recurrence rate, chest drain (+ pleurodesis 60-70% success)
Indwelling pleural catheter
Thoracoscopic drainage + pleurodesis

Question 29

why could drainage by an indwelling pleural catheter be used for ME

Answer 29

Avoid patient admission to hospital
Suitable for long term drainage
Improve quality of life
50% spontaneous pleurodesis

Question 30

how can talc pleurodesis (without infection) be used for ME

Answer 30

To prevent recurrence
Medicated talc
Created talc slurry to stick pleural together
Works in about 70%
Lung needs to be reinflated, output <200 ml/24 hr
Drain can’t be blocked or fall out
Pain/fever

Question 31

What is a harm-thorax

Answer 31

Not bloody effusion (hct >50%)
Traumatic, iatrogenic, Aortic dissection
Depending on cause
Resuscitate, urgent drainage (surgical drain), consider VATS pleurodesis and medical thoracoscopy