Restrictive lung disease and combo diseases Flashcards
What defines Lung restriction?
results in a reduction in:
- RV: Residual volume
- FRC: Functional residual capacity
- TLC: Total Lung capacity
lung function tests
What is the difference between restrive and obstructive lung function?
- there is also a reduced TLCO (the diffusion capacity of CO from capillaries to alveoli)
What causes skeletal and connective tissue restrictions?
- extensive burns affecting the chest wall
- obesity
- Kyphoscoliosis: the curvature of the spine characterised by abnormal vertebral curving
Give examples of Neuromuscular chest wall disorders
- Guillain-Barre: auto-immune syndrome, the immune system attacks your nerves
- Degenerative spinal diseases
- Motor neurone disease: gradual degradation of the nerves system
- Poliomyelitis (Polio): a viral illness, that can cause nerve injury leading to paralysis, difficulty breathing and potentially death
- Myasthenia gravis: weakness and rapid fatigue of voluntary muscles
What is pleural effusion?
- the abnormal accumulation of serous fluid in the pleural space/cavity
> 25 mL
- there is usually a net filtration of transudative (protein poor) fluid into the pleural space that is balanced with reabsorption from the parietal lymphatic
- when there is pleural effusion this doesn’t occur, as either too much fluid is produced or not enough is being taken away
What are some presenting symptoms of Pleural effusion?
- pleuritic chest pain
- dull aching pain
- the fullness of the chest (heavy)
- dyspnoea
- or asymptomatic
What are clinical signs of the effusion?
- decreased chest expansion
- absent breath sounds
- dullness to percussion
- compressive atelectasis (partial lung collapse) may cause bronchial breath sounds
- Tracheal deviation and a mediastinal shift is massive effusion
What would be seen in a chest x-ray of bilateral pleural effusion
- > 300 mls visible in the cxr
- blunted costophrenic angle
- Homogenous opacification
- loss of diaphragmatic and mediastinal borders
- meniscus
Explain Transudative Effusion
- due to an imbalance in Starlings forces across the pleural membrane
- have protein poor fluid
- often bilateral
- not associated with a fever, pleuritic pain, or tenderness on palpation
- the most common cause is congestive heart failure
Explain Exudative Effusion
- implies disease of the pleura or the adjacent lung
- increased protein, lactate dehydrogenase (LDH), cholesterol or WBC
- Measurement of all the above including pleural aspirate count, pH and glucose should be taken
- needs to be drained: tube thoracostomy or needle aspiration
What are the causes of Transudative Effusion?
Increased venous pressure
- Congestive heart failure
- fluid overload
- constrictive pericarditis
Low protein (decreased oncotic pressure)
- nephrotic disease
- Cirrhosis Hepatic hydrothorax (liver failure)
- Hypothyroidism
- Meia’s syndrome: benign ovarian fibroma
What are the causes of Exudative Effusion?
Infection
- acute bacterial infection,
- parapheumonic,
- empyema,
- TB
- PE: causing a pulmonary infarct
- Malignant cancer
- Inflammatory: rheumatoid arthritis
- Pancreatitis
- Dressler’s syndrome: 2-10 weeks post-MI
- Chylothorax
what will it show?
What Fluid studies can be carried out?
- pH: <7.2 indicates the need for tube drainage
- Cell counts: lymphocytosis suggests heart failure, malignancy TB
- Microscopy, Culture & Sensitivity (MC&S): infection
- Cytopathology: cancer cells
- Protein, glucose, LDH: Light’s criteria
- +/- triglyceride levels if chylothorax suspected
Lactate dehydrogenase
What is Light’s criteria for determining exudative effusion?
- when Protein pleural level/level in serum > 0.5
- LDH pleural level/level in serum >0.6
- LDH pleural level > 2/3 the upper limit of the normal level in the serum
How would you recognise a parapneumonic effusion?
- sterile inflammation
- pH > 7.2
- small/ free flowing
How would you recognise Empyema?
- infected pleural space
- pus cells present
Hct = Hematocrit
How would you recognise Haemothorax?
- pleural fluid Hct > 50% pf blood Hct
How would you recognise Hepatic hydrothorax?
- cirrhotic fluid transverses the diaphragm into the pleural space
How would you recognise Chylothorax?
- Triglycerides > 110mg/dL
- fluid looks milky
How does an effusion cause restriction?
- Compressive atelectasis
What happens if effusions are not drained?
- Parapneumonic effusions should heal as the pneumonia infection resolves (unless pH<7.2)
- Haemothorax and empyema require complete evacuation to prevent the development of fibrous visceral pleural peel -> trapped lung (unexpandable lung)
What occurs during spontaneous pneumothorax and what are the risk factors?
- rupture of the pleural blebs
- changes in intrapleural pressure
- often occur at rest
Risk Factors
- tall, thin, male, smoker
Describe the Intersitrium of the lung
- Intralobular Septa: this surrounds the alveoli, where the capillaries are found
- Interlobular Septa: outline the secondary lobules, this is where the lymphatics and veins of the lungs are
- these interstitial structures can be affected by inflammation or fibrosis (scarring)
ILD= Interstitial Lung Disease
What are the origins of Interstitial lung diseases
- IDF: Idiopathic pulmonary fibrosis
Inflammatory Diseases
- Sarcoidosis
- Autoimmune ILD
- Organic exposure leads to Hypersensitivity pneumonitis
Inorganic Exposure
- Silicosis
- Coal miners lung
- Asbestosis
What can be seen in Pneumoconiosis chest images, and what are the causes?
- nodular diseases common in silica and coal dust exposure
- arrows in the MRI point to progressive massive fibrosis
- arrows in the CT point to pleural plaques, caused by asbestos
- asbestos exposure can also lead to fibrosis
Explain the different levels of hypersensitivity Pneumonitis
Diffuse inflammation of parenchyma in response to inhaled antigen
•bird-fanciers, farmers, aspergillus (ubiquitous fungus),
Acute
- SOB, cough, fever, malaise, crackles within 4-6 hours of heavy exposure ]
- Often misdiagnosed as an infection
Subacute
•Gradual onset of symptoms, weight loss common
Chronic
- Insidious onset, history of acute episodes may be absent
- Incomplete resolution with the removal antigen
- May lead to irreversible fibrosis
What can be used to diagnose Hypersensitivity Pneumonitis?
- the precipitins test using Serum precipitins: circulating IGG antibody-antigen complexes
- negative results do not exclude HP
- usually steroid-responsive in early disease
- may progress to irreversible fibrosis
Explain Idiopathic Pulmonary Fibrosis
Progressive incurable restrictive lung disease, median survival 2-3 years
- disease of older age
- most patients have smoked
- mostly affects the lower & peripheral aspects of the lungs
- presents in imaging as fine peripheral lines & honeycomb cysts
- lots of fibroblast cells: thee make collagen
- there is minimal inflammation
What is the clinical presentation of Idiopathic Pulmonary Fibrosis?
symptoms and clinical signs appear gradually
- slowly progressing exertional dyspnoea: ultimately leads to dyspnoea at rest
- Non-productive cough
- Dry, inspiratory bibasal, velcro crackles
- Clubbing fingers
- abnormal pulmonary function test results: evidence of restriction and impaired gas exchange
What is the pathophysiology of Sarcoidosis?
How is it diagnosed?
- An (antigen) particle is inhaled
- In the lung it is loaded onto an MHC-II complex (of an antigen-presenting cell, aka APC). The lung is full of APCs, such as dendritic cells, on surveillance for microbes.
- Receptors on CD4+ T cells bind to the antigen
- APCs and antigen-bound T cells release cytokines
- These activate macrophages which organize into granulomas
- Granulomas also occur in TB and fungal infections, but in sarcoidosis they are sterile.
A biopsy demonstrating granulomas is needed to diagnose sarcoidosis.
What ways can Sarcoidosis manifest itself?
- Bilateral hilar lymphadenopathy
- Diffuse small nodules
- Nervous system disease; small fibre neuropathy from peripheral nerve damage
- sarcoidosis in the heart can lead to: heart block, arrhythmias, heart failure
- nodules and or violaceous plaques on the skin: (lupus pernio when it’s around the nose)
- Eyes and glands: uveitis, parotitis
- Systemic reaction: erythema nodosum
What are some symptoms of sarcoidosis?
- sometimes asymptomatic: especially in isolated lymphadenopathy
- organ-based symptoms: in the pulmonary sarcoidosis: cough, dyspnea with exertion, chest tightness
- systemic symptoms: fatigue, sweats, weight loss, fevers, generalized machines occur in many patients
What disease does this lung image show?
What would a PFT reveal in this case?
Lymphadenopathy: with essentially normal lung tissue
- decreased FEV1/FVC ratio
What disease does this lung image show?
What would a PFT reveal in this case?
Inflammatory sarcoidosis affecting lung
- lower spirometry and diffuse capacity function
What disease does this lung image show?
What would a PFT reveal in this case?
Fibrotic sarcoidosis
- sever restriction in PFT: inspiration and expiration reduced
What is the clinical management of sarcoidosis?
- Medication treatment if needed for symptoms or declining lung function: systemic corticosteroids (eg. prednisolone), +/- other immunosuppressant medications
- Screen for multi-organ disease: eye exam, EKG, blood tests for blood cell counts/liver function/kidney function/calcium
How is Cystic Fibrosis diagnosed?
- Genetic screening
- CFTR protein = 1480 amino acids
- Many gene alterations identified in CF
- ΔF508 (loss of phenylalanine at amino acid position 508) = most common
- ΔF508: CFTR protein doesn’t fold properly –> gets degraded
- Sweat Test: salty sweat levels of Cl- >60 mEq
What are the symptoms and lung features are seen in Cystic Fibrosis?
SYMPTOMS:
- Excessive mucous, difficult to mobilize
- Dyspnoea
EXAM FINDINGS:
- Wheezing
- Rhonchi
IMAGING FINDINGS:
- Bronchiectasis
- Mucous plugging
- Hyperinflation young age –> shrunken, fibrotic lungs later
What are infectious pulmonary complications of Cystic Fibrosis?
Acute infections
- Gram-positive common in young age –> both gram-positive and gram negatives in older age
- Resistance is a common and BIG problem: MRSA and pseudomonas aeruginosa
•
Chronic infection
- Pseudomonas and Burkholderia cepacia
- Allergic bronchopulmonary aspergillosis (ABPA) from aspergillus growing in the airways
What other pulmonary complications are there in Cystic fibrosis?
- Haemoptysis
- Respiratory failure
What treatments are there for cystic fibrosis?
- Airway clearance
- postural drainage
- chest physical therapy
- percussion chest
- Inhaled bronchodilators
- Mucus thinners
- Hypertonic nebulizer treatments
- Others
- Corticosteroids, inhaled is better than systemic
- Antibiotics
- CFTR potentiators: Ivacaftor
- Lung transplant
- Pancreatic enzyme replacement: lipase, protease, amylase
What other multi-system diseases are caused by Cystic fibrosis?
- Meconium ileus: bowel obstruction due to meconium in the child’s intestine being thicker and stickier than normal meconium
- Pancreatic insufficiency: thick mucus blocks pancreatic enzymes from entering the small intestine
- Malnourishment
- Osteoporosis
- Male infertility: blockage or absence of the sperm canal
