need to know Flashcards
what is ventilation
mechanical process of moving gas in and out of lungs
what must be right for ventilation to occur
intra alveolar pressure must be less then atmospheric pressure for air to flow into lungs during inspiration
what is boyles law
as volume of gas increases the pressure exerted by the gas decreases
what are the 2 forces holding the thoracic wall and lungs in close opposition
- intra-pleural fluid cohesiveness
- the negative intra-pleural pressure
what are the 3 pressure important in ventilation
- atmospheric
- intra-alveolar
- intra-pleural pressure
what are the inspiratory muscles used during normal resting breathing
- diaphragm
- external intercostal muscle
how do lungs recoil during expiration
alveolar surface tension
- elastic connective tissue
what is the law of Laplace
the smaller alveoli have a higher tendency to collapse
what do pulmonary surfactant do to surface tension
lower the surface tension of smaller alveoli thus preventing them from collapsing
what is resp distress syndrome caused by in babies
not producing enough surfactant
what are the muscles of active expiration
- internal intercostal muscle
- abdominal muscles
what is inspiratory capacity
Max volume of air inspired at end of normal quiet expiration
what is vital capacity
Max volume of air that can be moved out during single breath following Max inspiration
how to calculate inspiratory capacity
IC = IRV + TV
how to calculate vital capacity
VC = IRV + TV + ERV
how to calculate total lung capacity
vital capacity + residual volume
when does residual volume increase
when elastic recoil of lungs is lost
= emphysema
what is the FEV1/FVC ratio for airway obstruction
low
what is the FVC for lung restriction
low
what is the FVC for combination of obstruction and restriction
low
what is the FEV1/FVC ratio for combination of obstruction and restriction
low
what does peak flow meter estimates
the peak flow rate in patients with obstructive lung disease
what is the compliance of lungs
measure of effort that has to go into stretching or distending the lungs
what happens if the lungs are less compliant
more work required to give a degree of inflation
examples of when the lungs are less compliant
- pulmonary fibrosis
- oedema
- collapse
- pneumonia
- absence of surfactant
what is increased compliance of lungs called
emphysema
what happens when the lungs have increases compliance
the lungs are hyper-inflated and patients have to work harder to get air out the lungs
what is pulmonary ventilation
volume of air breathed in and out per minute
what is ventilation perfusion matching dependent upon
the ventilation and perfusion
what is perfusion
the rate which blood is passing through the lungs
what is considered alveolar dead space
ventilated alveoli which are not adequately perfused with blood
what are 4 factors which influence gas transfer across the alveolar membrane
- partial pressure gradient of O2 and CO2
- diffusion coefficient
- surface area of alveolar membrane
- thickness of alveolar membrane
what is daltons law of pressure
total pressure = sum of each individual component in the gas mixture
what is PaO2
partial pressure of O2 in alveolar air
what is PiO2
partial pressure of O2 in inspired air
what is flicks law of diffusion
the amount of gas that moves across a tissue is proportional to the area of the sheet
thicker = less exchange
what is henrys law
the amount of a gas dissolved in a given type and volume of liquid at constant temperature is proportional to the partial pressure of the gas in equilibrium with the liquid
what is the Bohr effect
release of O2 by conditions of the tissue leads to shift of the curve to the right
more oxygen is released
where is myoglobin present
in skeletal and cardiac muscle cells
what is the Haldane effect
removing O2 from Hb increases ability of Hb to pick up Co2 and CO2 generated H+
what are the respiratory centre locations
- pons
- medulla
- oblongata
- spinal cord
what is the pre-botzinger
in the medulla and causes breathing rhythm
what do peripheral chemoreceptors sense
tension of oxygen and carbon dioxide and H+ in the blood
what do central chemo receptors respond to
H+ in cerebrospinal fluid
what does a rise in arterial PCO2 result in
increased ventilation
what does a fall in arterial PO2 stimulate
peripheral chemoreceptors
results in increased ventilation
what does a rise in H+ stimulate
peripheral chemoreceptors causes hyperventilation and increase elimination of CO2 from body
what does patient have if ABGs show high PaO2 and low PaCO2 and high pH
respiratory alkalosis with no metabolic compensation
what is type I resp failure
hypoxia + normal or low CO2
what is type 2 resp failure
hypoxia + hypercapnia
what is the nasal cavity lined by
respiratory epithelium (pseudo stratified ciliated columnar)
underneath there is lamina propriety and connective tissue
what does the oropharynx transmit
both air and swallowed food so is lined by non-keratinised stratified squamous epithelium
what are the larynx walls made up of
cartilage and muscle except the vocal folds
what are the larynx walls covered in
stratified squamous epithelium
what is the trachea made up of
- RE
- basal lamina
- lamina propria of connective tissue
- submucosa of loose connective tissue
- cartilaginous rings
what is the bronchi made up fo
- RE
- lamina propria
- irregular shaped cartilage
do the bronchioles have cartilage
no
what the bronchioles made up of
- cuboidal epithelium
- lamina propria
what do terminal bronchioles contain
Clara cells
what are type 1 alveolar cells
simple squamous epithelium blood-air barrier
what are type 2 alveolar cells
polygonal shape with microvilli, contains surfactant
what is endoderm
lining of the trachea and bronchial tree
what is visceral mesoderm
all other lung tissue
mnemonic for lung maturation
ELEPHANTS PLAY CHESS in SUNNY AFRICA
- embryonic
- pseudoglandular
- canalicular
- saccular
- alveolar
what does stimulation of cholinergic fibres cause
bronchial smooth muscle contraction
what does stimulation of postganglionic non-cholingeric fibres cause
relaxation
what does stimulation cause
bronchial smooth muscle relaxation via B2-adrenoreceptors on airway smooth muscle cells activated by adrenaline released from the adrenal gland
what does mild asthma display
hypersensitivity and mild hyper reactivity
what is one major cause of asthma
due to an immune imbalance between Th1 and Th2 lymphocyte mediated response
what is Th2 lymphocyte activation
allergen through airway epithelium > CD4+ expresses t to THO cells that mature to Th2 cells
these activate B cells that mature to IgE secreting P cells
what else can Th2 lymphocytes release
IL4 and IL13 which cause mast cells to express IgE receptors
asthma treatments
- SABA
- LABA
- CystLT1 receptor antagonist
- methylxanthines
- glucocorticoids
- monoclonal antibodies directed against IgE
example of SABA
salbutamol
example of LABA
salmeterol, formoterol
must be co-administered with glucocorticoid
example of CysLT1 receptor antagonist
monteleukast
- blocks cysLT1 receptor for LTs from mast cells - bronchodilator
examples of methylxanthines
- theophylline
- aminophylline
how do methylxanhtines work
inhibits PDE3
examples of mild/moderate glucocorticoids
- beclometasone
- budesonide
- fluticasone
side effect of fluticasone
hoarse voice
example of severe glucocorticoid
prednisolone
example of monoclonal antibodies directed against IgE
omalizumab
what does blockage of M3 prevent
contraction of airway smooth muscle
what are the treatments used for COPD
- SAMA
- LAMA
- SABA
- LABA
- ultra LABA
- PDE4 inhibitor
example of SAMA
ipatropium
example of LAMA
tiotropium
example of ultra LABA
indacaterol
example of PDE4 inhibitor
rofumilast
what is the FVC in asthma
normal
what is FVC ini COPD
reduced
what is FEV1 response to beat agonist in asthma
> 15%
what is FEV1 response to beta agonist in COPD
<15%
what is the triad for asthma
- reversible airflow obstruction
- airway hyper responsiveness
- airway inflammation
what are the signs and symptoms of asthma
- episodic
- non-productive cough
- wheeze
- triggers
- family history
what is the diagnosis of asthma
- diurnal variation of peak flow rate
- reduced forced expiratory ratio (FEV1/FVC <75%)
- bronchospasm
diagnosis of severe asthma
- peak flow <50%
- tachycardia >110bpm
- > 25 resp/min
- cant complete sentences
what does cigarette smoke do
activate macrophages and airway epithelial cells in the respiratory tract which release neutrophil chemotactic factors (IL-8 and leukotriene B4)
what do neutrophils and macrophages release
proteases that break down connective tissue in the lung parenchyma and also stimulate mucus hyper secretion
what is the pathology in COPD
imbalance between proteases and antiproteases which lead to inflammatory changes in the airways including damage of the respiratory mucosa
what are the features of chronic bronchitis
- chronic neutrophilic inflammation
- mucus hyper secretion
- mucociliary dysfunction
- altered lung microbiome
- smooth muscle spasm and hypertrophy
- partially reversible
features of emphysema
- impaired gas exchange
- loss of bronchial support
- irreversible
what are the clinical syndromes of restrictive thoracic disease
- breathless on exertion
- cough but no wheeze
- finger clubbing
- inspiratory lung crackles
- central cyanosis
- pulmonary fibrosis
how to diagnose restrictive thoracic disease
- history
- reduced lung volumes: reduced FEV1 and FVC)
- reduced gas diffusion
- arterial oxygen desaturation
what are the early clinical features of lung cancer
- cough
- breathes for no reason
- chest infection doesn’t clear up
- coughing blood
- weight loss
- chest or shoulder pain
- tiredness
- hoarse voice
what are the 4 common smoking associated types of lung tumours
- adenocarcinoma
- squamous carcinoma
- small cell carcinoma
- large cell carcinoma
what is the worst cancer of the lung
small cell
how is small cell lung cancer treated
chemotherapy
what is the treatment of choice for non-small cell lung cancer
surgery
what does squamous cell cancer express
p63 and high molecular
what is carcinoid lung neoplasm
neuroendocrine system (low grade malignancy)
what his bronchial gland neoplasm
most often seen in salivary glands
what are the investigations done for lung cancer
- bronchoscopy (vocal cord palsy)
- medisatinoscopy
- CT scan of brain
- CT scan of thorax (tumour size)
- PET scan (mets)
what to percent in lung cancer
- tobacco smoking
- asbestos
- radon
when can transudate pleural effusion occur
- cardiac failure
- cirrhosis
- renal failure
when can exudate pleural effusion occur
- pneumonia
- TB
- abscess
- malignancy
what is mesothelioma
uncommon malignant tumour of lining of tumour or abdominal cavity
exposure to ASBESTOS
what are the symptoms of mesothelioma
- breathlessness
- chest pain
- weight loss
- fever
- sweating
- cough
what is the treatment for mesothelioma
- pleurodese effusion
- radiotherapy
- surgery
- chemo
- palliative
examples of upper tract infections
- coryza
- pharyngitis
- sinusitis
- epiglottis
- diphtheria
examples of lower tract infection
- acute bronchitis
- acute exacerbation of COPD
- resp distress
- pneumonia
- influenza
what is the main infection of TB
mycobacterial infection
what are the symptoms of TB
- persistent productive cough
- occasional haemoptysis
- pleuritic pain
- hoarseness
- upper zone crackles
- night sweats fever
- weight loss
what is the pathology of TB
type IV hypersensitivity reaction
what are the reasons for TB reactivation
- decreased T cell function
- reinfection at high dose or more virulent organism
what is the investigation for TB
broncho alveolar lavage
- Ziehl Neilsen stain
- CXR
side effects of rifampicin
orange fluids
side effect of isoniazid
neuropathy
side effect of pyrazinamide
joint pain
side effects of ethambutol
colour blindness
what therapy can reactivate latent TB
anti TNF therapy
pneumonia
inflammation of one or both lungs due to infection
what is the pathology of pneumonia
classical acute inflammatory response
what are the symptoms of pneumonia
- malaise
- anorexia
- sweats
- rigors
- myalgia
- arthralgia
- headache
- confusion
- cough
- pleurisy
- haemoptysis
- dyspnoea
- abdominal pain
- diarrhoea
what are the signs of pneumonia
- fever
- rigors
- herpes
- tachypnoea
- crackles
- rub
- cyanosis
- hypotension
investigation for pneumonia
- blood culture
- serology
- ABGs
- FBC
- urea
- liver funciton
- CXR
what is the most common cause pneumonia
strep pneumonia
what are the causative organisms of pneumonia
- herpes labials
- haem influenza (common in COPD patients)
- staph aureus
atypicals
- mycoplasma pneumonia
- chlamydophila
- legionella pneumophilia (water tanks, Spain)
- klebsiella (alcoholics)
- pneumocystis
what is lobar pneumonia
confluent consolidation of a complete lung lobe
what is broncho pneumonia
infection arising in bronchi or bronchioles
when does bronchiolitis usually occur
1st or 2nd year of life
what is are the early symptoms of bronchiolitis
- fever
- coryza
- cough
- wheeze
what are the severe symptoms of bronchiolitis
- grunting
- decrease O2
- intercostal/sternal drawing
what are the complications fo bronchiolitis
resp and cardiac failure
investigation for bronchiolitis
PCR
what is the epidemiology for bronchiolitis
every winter
no vaccine
what are the signs and symptoms of chronic pulmonary infection
- shadow on CXRR indicates cancer or infection
- weight loss s
- persistent sputum production
- chest pain
- increasing shortness of breath
what are the differential diagnosis of chronic pulmonary infection
- lung cancer
- intrapulmonary abscess
- empyema
- bronchiectasis
- cystic fibrosis
what are the risk factors of chronic pulmonary infection
- immunodeficiency
- immunosuppression
- abnormal innate host defence
- repeated insult
what are the ways a patient could be immunodeficient
- IgA deficiency
- hypo-splenism
- myeloma
- lymphoma
- HIV
what are the ways a patient could be immunosuppressant
- drugs (steroids, azathioprine, methotrexate, infliximab, chemo)
- malignancy
what are the 4 forms of chronic infection
- intrapulmonary absces
- empyema
- bronchiectasis
- cystic fibrosis
what are the symptoms of intrapulmonary abscess
- weight loss
- lethargy
- cough
- preceding an illness
what is the CT of intrapulmonary abscess
orange
what is intrapulmonary abscess caused by
septic emboli
what is empyema
pus in pleural space
what is the treatment of empyema
- IV abs
large = chest drain
what is the CT of bronchiectasis
signet ring
what is the cough like in bronchiectasis
- sputum
- chest pain
- recurrent LRTIs
what is the treatment of bronchiectasis
- stop smoking
- flu vaccine
- pneumococcal vaccine
- Abs (prophylaxis)
- anti-inflammatory
what is the defect in cystic fibrosis
CFTR channel defect so lose inhibition of sodium channel so cells fill with Na+ and increase in H2O so this leads to dryness at airways
where is gene located in cystic fibrosis
chromosome 7
what can cystic fibrosis cause
- bronchiectasis
- sputum
- biliary obstruction
- internal obstruction
- pancreas
- dysfunction
- infertility for males
- SALTY SWEAT
- failure to thrive
what is the genetic of cystic fibrosis
Del508 inherited by one of each parent
what is exacerbation management of cystic fibrosis
- antibiotics
- physiotherapy
- adequate hydration
- increase dietary input
what is interstitial lung disease
any disease process affecting lung interstitial
symptoms of interstitial lung disease
- breathlessness
- dry cough
what are the biopsies done for interstitial lung disease
- trans bronchial
- thoracoscopic
what type of hypersensitivity is sarcoidosis
- type 4
what is the diagnosis for sarcoidosis
- CXR (peripheral nodular infiltrate)
- tissue biopsy
- pulmonary function test
- blood test (ACE, raised Ca, increased inflammatory markers)
treatment for sarcoidosis
acute
- self-limiting (steroids)
chronic
- oral steroids
+ immunosuppression
what hypersensitivity is pneumonitis
type III
what is the aetiology of hypersensitivity pneumonitis
- farmers lung
- malt workers
- mushroom workers
- bird fancier
what are the symptoms of acute hypersensitivity pneumonitis
- cough
- breathless
- fever
- myalgia
what are the signs of hypersensitivity pneumonitis
- crackles
- hypoxia
- CXR = widespread pulmonary infiltrates
what is the treatment of acute hypersensitivity pneumonitis
- oxygen
- steroid
- antigen avoidance
clinical features of pulmonary embolism
- tachycardia
- tachypnoea
- cyanosis
- fever
- low BP
- crackles
- rub
- pleural effusion
- ABGs
- CXR = consolidation, pleural effusion
treatment of pulmonary embolism
anticoagulation (low heparin) + warfarin
signs of pulmonary hypertension
- central cyanosis
- dependent oedema
- raised JVP with v waves
- right ventricular heave at left parasternal edge
- murmur of tricuspid regurgitation
- enlarged liver
what is stridor
inspiratory wheeze due to large airways obstruction
what is Gillian barre syndrome
rapid-onset of muscle weakness caused by immune system damaging the peripheral nervous system
what is symptoms of Gillian barre syndrome
- changes in sensation start at feet and hands
- develop over hours to few weeks
what do to do diagnose DVT
ultrasound
what to do if massive PE suspected and CXR abnormal
CT pulmonary angiogram
what do goblet cells secrete
mucus
what do club cells secrete
are found in bronchioles and secrete glycosaminoglycans
what is the level of the male nipple
T4
histology of the respiratory epithelium
pseudostratified columnar epithelium with goblet cells and cilia
what supplies the upper respiratory tract
vagus nerve
what controls the trapezius
spinal accessory
where is a pleural effusion first seen
at chostodiaphragmatic recess
what is Horner syndrome
neuropathy compression of sympathetic nerve
what causes horners syndrome
ipsilateral Pancoast tumour
ipsilateral = same side
what is tenecteplase
thrombolytic drug
what does squamous cell carcinoma release
PTH
what does PTH do
is causes hypercalcaemia
what are symptoms of hypercalcaemia
‘moans, bones, groans and kidney stones’
- diarrhoea etc
what are the difference in symptoms between asbestosis and mesothelioma
asbestosis = cough and chest pain mesothelioma = no cough, pleural effusion
what does stony dull to percuss mean
pleural effusion
what disease causes pleural thickening
asbestosis
what disease causes cavitation on CT
TB
fungal
what disease causes consolidation on CT
pneumonia
what kind of joints are all symphysis
secondary cartilaginous
when you aspirate food where does it usually end up
right lower lobe