Random Ass Facts For Resp Flashcards
When does surfactant production begin in foetal development?
Around week 22
What is the most common gene causing cystic fibrosis and how does it lead to mucus accumulation?
DeltaF508 (Phe508del) - the gene encoding the cystic fibrosis transmembrane conductance regulator, an ion channel involved in the transport of chloride ions in the respiratory and pancreatic epithelium, leading to mucus accumulation
This gene is on chromosome 7 at CFTR gene
What are sign to look out for in a baby’s and young children for undiagnosed cystic fibrosis?
wheeze, poor feeding and failure to gain weight, frequent chest infections
Failure to pass meconium (stool) - new borns
Failure to thrive, pancreatic insufficient (loose greasy stool due to lack of lipases)
What does a heel prick test confirm?
Cystic fibrosis
Lung cancer can present with ipsilateral elevation of the hemidiaphragm due to compression of what nerve?
Phrenic nerve
What does methaemoglobin do to the oxygen dissociation curve?
Shifts it to the left
What is methaemoglobinaemia?
- Where is iron molecule is F3+ and not F2+ so can not bind to oxygen
- occurs due to environmental agents or medications (e.g. lidocaine and trimethoprim) or genetic conditions such as G6PD deficiency and pyruvate kinase deficiency
What causes Bird fanciers lung?
Avian proteins from bird droppings
What causes tobacco workers lung?
Aspergillus spp.
What causes farmers lung?
Thermophilic actinomycetes
What is responsible for hot tub lung?
Mycobacterium avium
How can cystic fibrosis lead to infertility in men?
Cystic fibrosis is associated with absent vas deferens
What is the investigation of chronic to confirm the diagnosis of bronchiectasis?
High resolution computed tomograpahy (although a chest x-ray is normally carried out first)
Characteristic feature include:
- Bronchial wall dilation
- Lack of bronchial tapering
What are the characteristic features of bronchiectasis on chest x-ray?
- Thickened bronchial walls (tramlines)
- Cystic lesions with fluid levels
- Collapsed areas with crowded pulmonary vasculature
- Scarring
What is Kartageners syndrome?
Defect in the cilia which reduces the ability of the lungs to clear mucus - this progresses to bronchiectasis as repeated infections and inflammation cause the airways to become widened and oedematous
Which physiological changes do occur following a tracheostomy?
- alveolar ventilation increased
- anatomical dead-space is reduced by 50%
- proportion of ciliates epithelial cells in the trachea may decrease
- splinting of the larynx may lead to swallowing difficulties
What is the pathogen in the majority of cases of Bronchiolitis?
Respiratory syncytial virus (75-80% of cases)
Other causes: adenoviruses, mycoplasma or secondary to a bacterial infection
What is bronchiolitis?
Condition characterised by acute bronchiolar inflammation
Features:
- common cold symptoms (including mild fever)
- dry cough
- increasing breathlessness
- wheezing, fine inspirations crackles (not always present)
- feeding difficulties associated with increasing dyspnoea are often the reason for hospital admission
What is Ménière’s disease>
Disorder of the inner ear of unknown cause. It is characterised by excessive pressure and progressive dilation of the endolymphatic system
Features:
- recurrent episodes of vertigo, tinnitus and hearing loss (sensorineural). Vertigo is usually the prominent symptom
- a sensation of aural fullness or pressure is now recognised as being common
- other features include nystagmus and a positive Romberg test
- episodes last minutes to hours
- typically symptoms are unilateral but bilateral symptoms may develop after a number of years
What are the 3 bones in the ear?
- malleus
- incus
- stapes
Foreign bodies lodges in the piriform recess ma damage what nerve?
The internal laryngeal nerve
What is the mechanism of action of aminophylline?
Binds to adenosine receptors and blocks adenosine-mediated bronchoconstriction
What is Cholesteatoma?
A non-cancerous growth of squamous epithelium that is ‘trapped’ within the skull base causing local destruction. It is most common in patients aged 10-20 years. Being born with a cleft palate increases the risk of cholesteatoma around 100 fold.
Main features
- foul-smelling, non-resolving discharge
hearing loss
Other features are determined by local invasion:
- vertigo
- facial nerve palsy
- cerebellopontine angle syndrome
Otoscopy
- ‘attic crust’ - seen in the uppermost part of the ear drum
What to chemoreceptors respond to to increase ventilation?
Respond to increased H+ in BRAIN INTERSTITIAL FLUID
How does the body control ventilation?
- Control of ventilation is coordinated by the respiratory centres, chemoreceptors, lung receptors and muscles.
- Automatic, involuntary control of respiration occurs from the medulla.
- The respiratory centres control the respiratory rate and the depth of respiration.
What would normal rebuts be when the Rinne and Weber tests are carried out?
- Rinne result: Air conduction > bone conduction bilaterally
- Weber result: same in both ears
What are the causes of increase anion acidosis?
MUDPILES
M - Methanol
U - Uraemia
D - DKA/AKA
P - Paraldehyde/phenformin
I - Iron/INH
L - Lactic acidosis
E - Ethylene glycol
S - Salicylates
Asthma is associated with what type of hypersensitivity reaction
Type 1 hypersensitivity
What is functional residual capacity?
Expiratory reserve volume + residual volume
What bacteria is a common cause of acute bacterial otitis media?
- Haemophilus influenzae
- Streptococcus pneumoniae
- Moraxella
What nerve roots contribute nerve fibres to the ansa cervicalis?
C1, C2 and C3
Ansa cervicalis muscles:
GHost THought SOmeone Stupid Shot Irene
GenioHyoid
ThyroidHyoid
Superior Omohyoid
SternoThyroid
SternoHyoid
Inferior Omohyoid
A 35-year-old man presents with fever, malaise, weight loss, dyspnoea, and pain in the shoulder & hip joints. He has raised erythematous lesions present on both legs. Blood tests show raised calcium levels and raised serum ACE levels. A chest x-ray shows bilateral hilar lymphadenopathy.
What is the most likely diagnosis?
Raised serum ACE levels - think sarcoidosis
What is sarcoidosis?
A multisystem disorder of unknown aetiology characterised by non-caseating granulomas. It is more common in young adults and in people of African descent
Features:
- acute: erythema nodosum, bilateral hilar lymphadenopathy, swinging fever, polyarthralgia
- insidious: dyspnoea, non-productive cough, malaise, weight loss
- skin: lupus pernio
- hypercalcaemia: macrophages inside the granulomas cause an increased conversion of vitamin D to its active form (1,25-dihydroxycholecalciferol
What are the syndromes associated with sarcoidosis?
- Lofgrens syndrome
- Mikulicz syndrome (outdated name??)
- Heerfordts syndrome
How to measure vital capacity?
Inspiratory reserve volume + tidal volume + expiratory reserve volume
Which area of the brain stem coordinates the basic rhythm of breathing?
Medulla oblongata
Causes of raised TLCO (total gas transfer)?
- asthma
- pulmonary haemorrhage (Wegener’s, Goodpasture’s)
- left-to-right cardiac shunts
- polycythaemia
- hyperkinetic states
- male gender, exercise
Causes of a lower TCLO (total gas transfer)?
- pulmonary fibrosis
- pneumonia
- pulmonary emboli
- pulmonary oedema
- emphysema
- anaemia
- low cardiac output
At which vertebral level would the diaphragm be encountered when inserting an IVC filter?
T8
When should legionella pneumophilia be suspected?
- where multiple otherwise fit people contract pneumonia in an air conditioned space
- hyponatraemia and lymphopenia are features associated with legionella pneumophilia
What causes a normal anion gap acidosis?
HARD UP
H - Hyperalimentation/hyperventilation
A - Acetazolamide
R - Renal tubular acidosis
D - Diarrhoea
U - Ureteral diversion
P - Pancreatic fistula/parenteral saline
Causes of hoearsness
- voice overuse
- smoking
- viral illness
- hypothyroidism
- gastro-oesophageal reflux
- laryngeal cancer
- lung cancer
What is the most common cause of Malignant otitis
Pseudomonas aeruginosa
What is the treatment for benign paroxysmal positional vertigo?
Epley manoeuvre - aims to dislodge otoliths by promoting movement of fluid in the semi-circular canals of the inner ear.
What vertebral levels is the larynx found?
Larynx is found in the anterior neck at the level of the C3–C6 vertebrae
Which adverse consequence may occur as a result of chest drain insertion?
Winging of the scapula - Long thoracic nerve is susceptible to damage during chest drain insertion
What is Chylothorax?
A type of pleural effusion where lymphatic fluid accumulates in the pleural cavity
What is a pyothorax?
Type of pleural effusion where pus accumulate in the pleural cavity
What is the most common type of lung cancer?
Adenocarcinoma
Almost exclusively related to asbestos exposure. This is an aggressive and incurable cancer related to the pleura. It would not be noticeable as an upper lobe mass. A loss of lung volume or pleural opacity is more likely in the first instance.
Mesothelioma
A rare subtype of lung cancer and is less likely to occur than adenocarcinoma. The classic presenting features are cough, haemoptysis, and recurrent chest infections.
Bronchial adenoma
A rare subtype of lung cancer and is less likely to occur than adenocarcinoma. The classic presenting features are cough, haemoptysis, and recurrent chest infections.
Small cell carcinoma
A 65-year-old man visits his GP after a diagnosis of stage III lung cancer. He asks the doctor about the complications he might expect from his condition.
What is he at increased risk of developing?
Pneumothorax
What vertebral levels does the phrenic nerve start at? What does the phrenic nerve supply?
- C3,4,5
- supplies:
- diaphragm, sensation central diaphragm and pericardium
What crosses the diaphragm at T12?
Aorta, thoracic duct, azygous vein
What crosses the diaphragm at T10?
Oesophagus and the vagal trunk
At what level does the trachea bifurcate? The carina
T5 (or T6 in tall subjects)
Clubbing (hypertrophic pulmonary osteoarthropathy, HPOA) is associated with squamous cell carcinoma
True
What is the commonest cause of empyema?
Streptococcus pneumoniae - also the most commonest cause of pneumonia
Which sensory nerve branches off the superior laryngeal nerve?
The internal laryngeal nerve
What is a cervical rib due to?
Elongation of the transverse process of the 7th cervical vertebra. It is usually a fibrous band that attaches to the first thoracic rib
How does Myasthenia gravis lead to a restrictive pattern of lung disease?
Myasthenia gravis leads to muscle weakness of the chest wall resulting in incomplete expansion during inspiration
Peritonsillar abscess (quinsy)
A peritonsillar abscess typically develops as a complication of bacterial tonsillitis.
Features include:
- severe throat pain, which lateralises to one side
- deviation of the uvula to the unaffected side
- trismus (difficulty opening the mouth)
- reduced neck mobility
What is the definition of this lung volume?
Maximum volume of air that can be expired at the end of a normal tidal expiration
How can COPD occur in a young non-smoker?
- A-1 antitrypsin deficiency,
- a relatively common autosomal co-dominant genetic condition
- This protein would normally protect the lung cells against the destructive action of neutrophil elastase that destroys alveolar walls causing emphysema and thereby COPD.
Treatment of Ramsay Hunt syndrome
Oral aciclovir (7 days) and corticosteroids (prednisolone-5 days)
