Respiratory Flashcards
Definition of chronic bronchitis
Inflammation of bronchial tubules, with a productive cough for 3/12 for at least 2 years
Give 3 risk factors for chronic bronchitis
Air pollutants
Dust and silica
Genetic factors
Which ratio is particularly low in chronic bronchitis?
FEV1 to FVC ratio
How is the total lung capacity usually affected in chronic bronchitis and why?
High due to air trapping
What type of cells line the airways?
Ciliated pseudostratified columnar epithelial cells- with goblet cells
Give the two layers that make up the lamina propria
Basement membrane and loose connective tissue
Give the two layers of the submucosa
Smooth muscle and connective tissue
How is mucous made and secreted?
Made by goblet cells, secreted by bronchial mucinous glands
How does exposure to irritants and chemicals affect the cilia?
They become shorter and less mobile which makes it more difficult for them to move mucous
How does exposure to irritants and chemicals affect the bronchial mucinous glands and goblet cells?
Hypertrophy and hyperplasia
What is the Reid Index and what value indicated chronic bronchitis
Thickness of glands/ thickness of wall
chronic bronchitis >40%
Give 5 Signs and Symptoms of chronic bronchitis
Wheeze Crackles (rales) Hypoxemia Hypercapnia Cyanosis
How can pulmonary HTN occur as a result of COPD? What does this eventually lead to?
Blood vessels vasoconstrictor in areas with decreased gas exchange to shunt blood
In chronic bronchitis, this is a large proportion of the lung
Increases pulmonary vascular resistance
Increased work from R side of heart leads to right sided heart failure (Cor-Pulmonale)
How would you treat chronic bronchitis?
Reduce risk factors Manage associated illnesses Supplemental oxygen Medication: Bronchodilators Inhaled steroids Antibiotics
Give examples of the following which could be used for COPD:
Bronchodilators
Inhaled steroids
Salbutamol, salmeterol (Beta-2 agonists)
Ipratropium, tiotropium (anticholinergics)
Beclomethasone dipropionate
How does smoking lead to emphysema?
It causes an inflammatory reaction which leads to the release of immune cells and the release of proteases (elastase and collagenases) which break down structural proteins in the connective tissue layer of the alveoli
Use Bernoulli’s principle to explain why the airways collapse during exhalation in a patient with emphysema
Fluid moves at a higher velocity with a lower pressure
Low pressure pulls airways inwards
Since there is a loss of elastin, airways can no longer withstand this pressure during exhalation
How does a loss of elastin affect compliance in emphysema?
Increased compliance, therefore inhalation causes easy expansion and the lungs hold on to air rather than expelling it during exhalation
How does a loss of elastin affect area available for gas exchange in emphysema?
Reduced SA available for gas exchange since a loss of elastin leads to a breakdown of alveolar septa and therefore neighbouring alveoli form larger air spaces
Describe the characteristics of centriacinar emphysema
Most common
Seen with cigarette smoking
Damages proximal alveoli
Typically affects upper lobe of lungs
Describe the characteristics of panacinar emphysema
Associated with alpha-1 antitrypsin deficiency
Entire acinus affected equally
Typically affects lower lobes of the lungs
What is the usual purpose of alpha-1 antitrypsin and why can a deficiency lead to emphysema?
It is a protease inhibitor which protects against unintended damage
Deficiency means no inhibition and therefore damaged air sacs
Describe the characteristics of paraseptal emphysema
Affects distal alveoli
Affects peripheral lung tissue near interlobular septa
Ballooned alveoli can rupture and cause a pneumothorax
Give 5 symptoms of emphysema
Dyspnoea Exhaling slowly through pursed lips (increases airway pressure and prevents collapse) Weight loss Hypoxaemia Cough with some sputum
Give a visible sign of emphysema
Air trapping and hyperinflation (‘Barrel chest’)
Give three signs you may see on a CXR in emphysema
Increased anterior-posterior diameter
Flattened diaphragm
Increased lung-field lucency
Give the three conditions in the atopic triad
Asthma
Atopic dermatitis
Allergic rhinitis
In allergic asthma, how is the allergen initially recognised by the body?
Allergen is picked up by dendritic cells and presented to T2 helper cells
Which cytokines are released by T2 helper cells in allergic asthma and what response do they induce?
IL-4: Production of IgE antibodies which trigger mast cells, mast cells then go on to release histamine, leukotrienes and prostaglandins
IL-5: Production of eosinophils which release more cytokines and leukotrienes
At which point does allergic asthma become irreversible?
Signs of oedema, scarring, fibrosis
Describe the hygiene hypothesis
Reduced early exposure to bacteria/ viruses alters the proportion of immune cells
Give 4 symptoms of asthma
Dyspnoea
Chest tightness
Wheezing
Coughing with sputum
How might asthma be classified?
Frequency of symptoms
Measure amount of obstruction (FEV1 and PEFR)
Frequency of medication use
Which medications may be used in the treatment of asthma?
Bronchodilators: SABAs, anticholinergics
Severe- Daily corticosteroids, LABA, leukotriene antagonists
Very severe- IV corticosteroids, magnesium sulfate, oxygen therapy
What percentage of lung cancer cases are small cell and non- small cell?
Small cell- 15%
Non-small cell- 85%
Describe the characteristics of small cell lung cancer
Tumour grows proximally close to the hylum
Involved neuro-endocrine cells in the area
Endocrine cells involved undergo mutation and produce hormones
Paraneoplastic syndrome
Describe the characteristics of adenocarcinoma
Most common non-small cell lung cancer
Tumour grows in peripheral lung tissue
Involves glands within the lung
Describe the characteristics of squamous cell carcinoma
Tumour grows close to the main bronchus
Obstruction of airway
Cells lining airway mutate from columnar cuboidal to squamous
Describe the characteristics of large cell carcinoma
Can present in peripheral or proximal lung tissue
Fast growing
Give 5 signs and symptoms of lung cancer
Cough weight-loss Haemoptysis Dyspnoea Chest pain
Give 5 risk factors for lung cancer
Smoking Radon Air pollution Asbestos Nickel Arsenic Family/ genetic factors
Describe the affects of pancoast tumour involvement in lung cancer
Tumour growth on apical lung surface can block part of the brachial plexus:
Shoulder/ arm pain
Weakness of ipsilateral side
Horner’s syndrome
Give three examples of mediastinal involvement in lung cancer
Pleural effusion- chest pain and dyspnoea
Pericardial effusion
Obstruction of SVC- blocks flow
How does the stimulation of angiogenesis in lung cancer cause problems?
Leaky and tortuous vessels form and these may rupture causing haemoptysis
Give 4 examples of blood involvement in lung cancer
Anaemia
Leukocytosis
Thrombocytosis
Hypercoaguable disorders
Give the common sites of metastases in lung cancer
Brian, liver, adrenal glands and bone
Define paraneoplastic syndrome and give which lung cancers it typically occurs with
Syndromes that occur not related to: Invasion Obstruction Metastasis of the primary tumour -Typically small cell lung cancer and squamous cell carcinoma
Describe ectopic Cushing’s syndrome (Paraneoplastic)
Hormone released by tumour stimulates the adrenal glands to release cortisol
Increase in ADH increases water retention
Increase in PTH, breaks down bone and releases calcium into plasma- hypercalcaemia
Describe hypertrophic osteoarthropathy
Clubbing- fluid collecting in soft tissues at the end of fingers
Periosteal proliferation of the tubular bone
Give 5 common clinical findings on a chest x ray in lung cancer
Hilal enlargement Pulmonary opacity Rib bone lesions Pleural effusion Lung collapse
How might lung cancer be managed?
Surgery- removal of tumour for stage I and II
Radiotherapy
Chemotherapy- Radio/ Chemo combination for stage III
Laser therapy and stenting- to manage airway obstruction causing serious symptoms
Describe primary haemostasis
Platelets adhere and activate by collagen and tissue factor
Platelets recruit more and form a plug
Describe secondary haemostasis
Clotting factors made by the liver are cleaved and this activates fibrinogen to fibrin
Fibrin polymerises and deposits to form a mesh around the platelets forming a hard clot
How is fibrin broken down and what is the product?
Broken down by plasmin and produces D dimers
How might a clot in the heart progress if an atrial septal defect is present?
Goes from right to left atrium and bypasses the lungs, clot is pumped out often to the brain
Embolic stroke
Give the three components of Virchow’s Triad
Stasis: platelets and clotting factors contact the endothelium
Hyper-coagulation: altered amounts of clotting factors
Damage: Infections, chronic inflammation
How can a pulmonary embolism lead to R sided heart failure?
PE increases vascular resistance as the heart must exert more pressure to move blood past obstructed arteries
How would you diagnose a PE?
CT angiogram
V/Q scan
D-dimer blood test
How would you treat a pulmonary embolism?
Thrombolytic enzymes Pulmonary thrombectomy Long term: Anticoagulant medications: Warfarin, heparin Compression stockings Calf exercises
Give 3 features of TB that make it resistant
Can resist weak disinfectants
Survives on dry surfaces
Waxy cell wall- from mycelia acid
What does “acid fast” mean and how is it tested for?
Can hold on to dye despite alcohol exposure
Bright red when Ziehl-Neelsen stain is used
How does TB survive despite phagocytosis by a macrophage?
It produces a toxin which inhibits lysosome-phagosome fusion and proliferates
What is the difference between the following: Ghon focus, Ghon complex, Ranke complex
Ghon focus is a small area of granulomatous inflammation
Ghon complex is when adjacent lymph nodes are involves/ infected
Ranke complex is when there is calcification
If there is reactivation of the Ghon complex in TB, where does the infection usually spread to and why?
Upper lobes of the lung as they are best oxygenated
When TB disseminates which systems can it affect and how?
Lungs- bronchopneumonia
Kidneys- sterile pyuria (WBC in urine)
Brain- meningitis
Lumbar vertebrae- Pott disease
Adrenal glands- Addison’s disease (adrenal insufficiency)
Liver- hepatitis
Cervical lymph nodes- lymphadenitis in the neck (scrofula)
How is TB tested for?
Purified protein derivative (PPD)- Intradermal skin test (Mantoux skin prick)
Tuberculin- component of TB injected, if previously exposed there will be an immune reaction
Interferon gamma release assay- evidence in blood
Give 5 signs and symptoms of TB
Fever Night sweats Weight loss Haemoptysis Fatigue
Give the treatment for latent TB
Isoniazid for 9 months
Give the treatment for active TB
Isoniazid and rifampicin for 6 months
Pyrazinamide and ethambutol for the first 2 months
Give 3 bacterial causes of typical pneumonia
Streptococcus pneumoniae
Haemophilus Influenzae
Staph Aureus
Give 3 bacterial causes of atypical pneumonia
Mycoplasma pneumonia
Chlamydophilia pneumoniae
Leigonella pneumoniae
Give an example of a fungal cause of pneumonia
Histoplasmosis
Blastomycosis
How is aspiration pneumonia acquired?
Gag reflex can be compromised by:
Drug/ alcohol abuse
Brain injury
Swallowing issues
Define lobar pneumonia
Complete consolidation of whole lung lobe
Mostly caused by S. pneumoniae
Give the stages of lobar pneumonia
Congestion- blood vessels and alveoli fill with fluid
Red hepatization- exudate (neutrophils, RBCs and fibrin) fill airspaces
Grey hepatization- colour change, RBCs in exudate break down
Resolution- exudate digested by enzymes
Give 4 symptoms of pneumonia
Dyspnoea Chest pain Productive cough Fatigue Fever
Describe a typical CXR for the following:
Bronchopneumonia
Lobar pneumonia
Atypical pneumonia
- Patchy areas spread throughout
- Fluid localised to a single lobe
- Concentrated in perihilar region
Describe the difference between type I and type II pneumocytes
Type I- squamous cells, nearly continuous layer
Type II- cubes with microvilli, secreting surfactant which prevents alveolar collapse
Describe the process of pulmonary fibrosis after the alveolar lining is damaged
Type I pneumocytes release transforming growth factor beta-1
This causes the type II pneumocytes to stimulate fibroblasts to proliferate and develop into myofibroblasts
Therefore too much collagen is produced, thickening the interstitial layer
Give 3 risk factors for pulmonary fibrosis
Old age
Being male
Tobacco smoking
Give 3 ways in which interstitial lung disease affects lung function
Decrease in total lung capacity
Decrease in forced vital capacity
Decrease in forced expiratory volume
Give 4 signs and symptoms of pulmonary fibrosis
Coughing
SOB
Cyanosis
Digital clubbing
Give two indicators of pulmonary fibrosis on a CT scan
“Honeycombing” and thickening of interstitial walls
Give 3 possible treatments for pulmonary fibrosis
Supplemental oxygen
Antifibrotic medication
Lung transplant
Define sarcoidosis
T-cell accumulation in organs, forming granulomas
Give 5 systemic symptoms of sarcoidosis
Fatigue Weakness Aching muscles Swollen lymph nodes Lack of appetite Weight loss
Give 4 respiratory symptoms of sarcoidosis
SOB
Dry cough
Wheezing
Suffocation
Give 3 symptoms of sarcoidosis affecting the eyes
Blurred vision
Tearing
Photophobia
How would sarcoidosis be diagnosed?
CXR- looking for granulomas
Blood test- looking for hyercalcaemia and raised ACE
Biopsy- lung tissue/ skin/ lymph nodes
Define bronchiectasis
A disease in which there is permanent enlargement of parts of the airways
What type of genetic disorder is cystic fibrosis?
Autosomal recessive
Which gene in affected in cystic fibrosis
Cystic fibrosis transmembrane conductance regulator (CFTR gene)
What is the purpose of the CFTR protein?
It pumps chloride ions into secretions, drawing water with them to thin the secretions
How does the mutation affect the CFTR protein?
It is misfiled and so cannot migrate from the ER to the cell membrane
What is the risk in newborns with cystic fibrosis?
If the meconium is thick and sticky it can get stuck in the intestines, this is called a meconium ileus and is a surgical emergency
What happens if thick secretions block the pancreatic ducts in cystic fibrosis?
Pancreatic enzymes don’t reach the small intestine
Proteins/ fat are therefore not absorbed which leads to:
Poor weight gain
Failure to thrive
Steatorrhea (fat containing stools)
What happens if pancreatic enzymes back grade to cells lining pancreatic ducts in cystic fibrosis?
Self-digestion leading to acute/ chronic pancreatitis and the development of cysts and fibrosis
This can cause insulin dependent diabetes
How does cystic fibrosis cause lung problems?
Thick mucous and defective mucociliary action leads to the colonisation of bacteria in the lung
Increased bacterial load can lead to a cough, fever and CXR changes
Give some possible consequences of chronic bacterial infection and inflammation in CF
Bronchiectasis- wall damage and permanent dilation of bronchi
If inflammation erodes into a blood vessel this can cause haemoptysis
What is the risk of repeated CF exacerbations?
Respiratory failure
How is cystic fibrosis diagnosed?
Newborn screening detects pancreatic enzyme released into blood when pancreas is damaged (IRT-immunoreactive trypsinogen)
How is cystic fibrosis treated?
Fat-soluble vitamins Extra calories Replacement pancreatic enzymes Chest physio Inhalers N-acetylcysteine- mucolytic Lung transplant Lumacaftor- brings protein to cell membrane Genetic treatment
Give 3 ways in which excess fluid builds up in the pleural space
Transudative- too much leaves the capillaries due to an increase in hydrostatic or decrease in oncotic pressure
Exudative- Inflammation of pulmonary capillaries (so more leaky)
Too little fluid drained- lymphatic effusion
Describe how a change in hydrostatic pressure can lead to pleural effusion
Heart failure leads to a back up of blood into the pulmonary vessels, increasing the pressure and forcing fluid into the pleural space
Describe how a change in oncotic pressure can lead to pleural effusion
Cirrhosis or nephrotic syndrome can lead to a drop in oncotic pressure
Give 4 causes of exudative pleural effusion
Malignancy
Inflammatory conditions such as lupus
Trauma
Infection such as pneumonia
Give 2 causes of lymphatic effusion
Damage to the thoracic duct during surgery
Tumours
Give a characteristic of pleural effusion pain
Worse when lying down
How would pleural effusion be diagnosed?
Decrease in breath sounds
Dullness to percussion
Decrease in tactile fremitus
(If large effusion there may be decrease in aeration and trachial deviation)
In a standing X ray- fluid displaces air and there is a blurred costophrenic angle
After removal via thoracentesis how would different types of pleural effusion fluid appear?
Transudative fluid is clear
Exudative fluid is cloudy- full of immune cells
Lymphatic fluid is milky- full of fats
What is the light criteria to determine whether fluid is exudative?
Fluid protein: serum protein > 0.5
Fluid LDH: serum LDH > 0.6
Fluid LDH > 2/3 normal upper limit of serum LDH
If fluid cholesterol level is > 45mg/dL
How would you treat a small pleural effusion from heart failure?
Diuretics
Sodium restriction
How would you treat a large pleural effusion from lung cancer?
Draining with a tube
Describe a pneumothorax and presenting symptoms
Abnormal collection of air in the pleural space Symptoms: Chest pain SOB Tiredness
How does a tension pneumothorax occur?
One way valve formed by an area of damaged tissue
More air enters but none can escape
There is an oxygen shortage and low blood pressure
How does the body compensate when a tension pneumothorax occurs?
Increases respiratory rate
Increases tidal volume
How would you treat a pneumothorax?
Conservative
Needle aspiration
Chest tube
Pleurodesis
Give 3 ways in which pulmonary hypertension can occur
L sided heart failure or valvular dysfunction leading to a backup of blood in the pulmonary veins
Chronic lung disease leading to vasoconstriction in an attempt to shunt blood away from damaged areas
Chronic thromboembolic pulmonary HTN due to recurrent blood clots in pulmonary vessels increasing vascular resistance
Give 3 congenital heart defects as causes of pulmonary HTN
Ventricular septal defect
Atrial septal defect
Patent ductus arteriosus
Give 4 examples of disorders which could lead to pulmonary HTN
Lupus
Infections like HIV
Thyroid disorders
Inherited genetic mutations
How do connective tissue disorders such as Lupus/ thyroid disorders lead to pulmonary HTN?
They cause damage to endothelial cells lining pulmonary arteries, this releases chemicals such as endothelin-1, serotonin and thromboxane which cause pulmonary arteriole constriction and hypertrophy of the smooth muscle
Give 3 consequences of R sided heart failure when blood backs up into the venous system
Increased jugular venous pressure
Fluid build up in the liver- hepatomegaly
Fluid build up in the legs-oedema
How would pulmonary HTN be diagnosed?
Echocardiogram showing an increased pressure in pulmonary arteries and R ventricle
Follow up tests to identify underlying cause
How would you treat pulmonary HTN?
Supplemental oxygen
Cause dependent:
If cariogenic- meds that boost heart performance and lower BP
If pulmonary arterial HTN- Endothelin receptor agonists and prostacyclins (dilate pulmonary arterioles and inhibit smooth muscle hypertrophy)
Give 5 symptoms of a mesothelioma
Dyspnoea Swollen abdomen Chest wall pain Fatigue Weight loss
Give 3 risk factors for mesothelioma
Asbestos exposure
Genetics
Infection with simian virus 40
How would you diagnose a mesothelioma?
CXR and CT
Confirmed by examining fluid produced by cancer/ tissue biopsy
How would you treat a mesothelioma?
Surgery
Radiation therapy
Chemotherapy- cisplatin and pemetrexed
Pleurodesis
Describe Goodpasture syndrome
An autoimmune disease i which antibodies attack the basement membrane (specifically alpha-3 subunit of type IV collagen) in the lungs and kidneys leading to failure
Give 4 systemic symptoms of Goodpasture syndrome
Malaise
Weight loss
Fatigue
Fever
Give 4 lung symptoms of Goodpasture syndrome
Haemoptysis
Chest pain
Cough
Dyspnoea
Give 5 kidney symptoms of Goodpasture syndrome
Haematuria Proteinuria Oedema Increased urea in the blood HTN
How would you diagnose Goodpasture syndrome?
Biopsy to look for anti-GBM antibodies (anti-glomerular basement membrane)
How would you treat Goodpasture syndrome?
Plasmapheresis
Immunosuppressant drugs- Cyclophosphamide, prednisone and retuximab
Describe Wegner’s syndrome
Systemic autoimmune disorder that involves granulomatosis and polyangitis
Give 5 signs and symptoms of Wegner’s syndrome
Lungs- primary nodules, infiltrates, pulmonary haemorrhage: haemoptysis Kidney- glomerulonephritis Nose- pain, nosebleeds Ears- conductive hearing loss Eyes- scleritis
Which antibodies are responsible for the inflammation in Wegner’s syndrome?
Anti-neutrophil cytoplasmic antibodies (ANCAs)
How would you treat Wegner’s syndrome?
Immunosuppressants- Rituximab, cyclophosphamide and high dose corticosteroids
Plasma exchange
Kidney transplant
Give 5 symptoms of influenza
Fever Cough Nasal congestion Hoarseness Throat pain
Describe the differences between influenza A, B and C
A- natural hosts are wild aquatic birds, can cause pandemics in humans, most virulent human pathogens
B- Almost exclusively infects humans, degree of immunity acquired due to lack of genetic diversity
C- sometimes causes sever illness/ local epidemics, less common
Why should children and teenagers avoid taking aspirin during an influenza infection
It can lead to Reye’s syndrome which is a rapidly progressive encephalopathy
Describe hypersensitivity pneumonitis
Inflammation of the alveoli within the lung caused by hypersensitivity to inhaled organic dusts
Give 3 symptoms for each of acute, subacute and chronic hypersensitivity pneumonitis
Acute- fever, chills, malaise, cough, chest tightness, SOB
Subacute-SOB, fatigue, productive cough, weight loss, pleurisy
Chronic-cough, progressive SOB, fatigue, weight loss, clubbing, tachypnoea, respiratory distress, inspiratory crackles
What type of sensitivity is hypersensitivity pneumonitis
III and IV
Give 5 signs and symptoms of laryngitis
Dry/ painful throat Cough Increased saliva production Dysphagia Globus pharyngeus Swollen lymph nodes
Give examples of the 4 causes of laryngitis
Trauma- damage to vocal folds (iatrogenic)
Fungal- histoplasma, blastomyces
Bacterial-group A strep, strep pneumoniae
Viral- rhinovirus, influenza, adenovirus
Give 3 causes of chronic laryngitis
Allergies
Autoimmune
Irritation of vocal folds due to reflux
How would you diagnose laryngitis?
Laryngoscopy: Erythema Oedema Dilated vessels (acute) Stiff vocal folds
How would you treat acute laryngitis?
Trauma- vocal hygiene
Viral- analgesia, rest, mucolytics
Bacterial- Abx
Fungal- antifungals
How would you treat chronic laryngitis?
Granulomatous- systemic corticosteroids
Reflux- antacids, PPI, behavioural changes
Inflammatory- topical nasal steroids, immunotherapy, antihistamines
Autoimmune- cyclophosphamide, prednisolone
Give 5 signs and symptoms of tonsillitis
Sore throat Red, swollen tonsils Pain on swallowing Fever Headache
Give 5 viral causes of tonsillitis
Adenovirus Rhinovirus Influenza Coronavirus Respiratory syncytial virus
Give the main bacterial cause of tonsillitis
Group A beta-haemolytic strep: strep throat
Give the treatment for tonsillitis
Analgesia
If bacterial: Abx- penicillin or amoxicillin
Give 3 symptoms of sinusitis
Headache/ facial pain
Thick nasal discharge
Localised headache/ toothache that is worsened by tilting the head forward and with valsalva manoeuvres
Give 5 possible complications of sinusitis
Orbital cellulitis Osteomyelitis of facial bones Middle ear problems Abscesses Meningitis
How can sinusitis be classified?
Acute <4 weeks
Recurrent >4 episodes in a year
Subacute <12 weeks
Chronic >12 weeks
By location: Maxillary Frontal Ethmoidal Sphenoidal
Give potential causes of sinusitis
Dental origin
Precipitated by an earlier upper resp tract infection: rhinoviruses, coronaviruses and influenza viruses
Bacterial- strep. pneumoniae, haemophilus influenzae
