WEEK 2 - sub-acute breathlessness Flashcards
give 4 features of an asthmatic epithelium
- mucus plug
- absence of ciliated epithelium
- thickened basal membrane
- hypertrophy and hyperplasia of smooth muscle
name 3 bacterium that commonly cause resp disease
- streptococcus pneumoniae
- haemophilus influenzae
- moraxella catarrhalis
name a virus that commonly causes respiratory disease
influenza A
name 2 fungi that commonly cause respiratory disease
- aspergillosis fumigatus
- pneumocystis jiroveci
what kind of bacteria are:
- streptococcus pyogenes ‘group B strep’
- staphylococcus aureus
- streptococcus pneumonia
gram positive cocci
what kind of bacteria are:
- listeria monocytogenes
- clostridium difficile
gram positive bacilli
name a gram negative cocci
neisseria meningitidis
name 3 gram negative bacilli
- escherichia coli
- legionella pneumophilia
- pseudomonas aeruginosa
what are 5 signs/symptoms that make asthma a likely diagnosis?
- breathless on exertion
- chest tightness
- whistling noise/wheeze
- nocturnal cough
- history of hay fever
what tests would you want to perform to confirm a diagnosis of asthma?
- spirometry
- peak flow
- peak flow diary
- exhaled nitric oxide (FeNO)
Salbutamol is a _______ _______ _________ and classed as a _______ medication. It works quickly to relax the airway muscles and has immediate effect.
QVAR (beclomethasone dipropionate) is an inhaled ____________ and acts to reduce _____________ in the airways. As a result it is classed as a ___________ medication as it doesn’t have an immediate effect and may take ________ to work and is used to prevent ongoing asthma symptoms, by reducing airway inflammation and thereby _________ ___________ to stimuli like cold air.
Salbutamol is a short acting bronchodilator and classed as a reliever medication. It works quickly to relax the airway muscles and has immediate effect.
QVAR (beclomethasone dipropionate) is an inhaled corticosteroid and acts to reduce inflammation in the airways. As a result it is classed as a preventer medication as it doesn’t have an immediate effect and may take weeks to work and is used to prevent ongoing asthma symptoms, by reducing airway inflammation and thereby bronchial hyperreactivity to stimuli like cold air.
what type of drugs are salbutamol and terbutaline?
short acting bronchodilators - SABA
what is salmeterol?
long acting bronchodilator - LABA
name 4 inhaled corticosteroids
- beclometasone
- fluticasone
- ciclesonide
- budesonide
name 3 LABA/ICS
- seretide
- fostair
- symbicort
do i need to know?
what are the key principles regarding inhaler prescribing?
- Inhalers should be prescribed by brand name to ensure patients receive the correct device, with which their inhaler technique has been assessed and they are able to use
- Inhaler technique should be assessed prior to prescribing inhalers in patients who have never used inhaled medication before
- Check inhaler technique at every opportunity / encounter with the patient and before considering dose escalation
- Whenever possible, prescribe patients the same inhaler device for each drug class
What types of inhaler devices are there? And what advice do you give to patients on how to use?
- metred dose inhalers (MDI) — inhale slow and steady
- dry powdered inhalers (DPI) — inhale quickly and deep
- breath actuated inhalers (BAI)
global warming potential of MDI vs DPI
dry powdered inhalers do not contain a propellant and have much lower global warming potential
MDI inhalers are delivered by propellant such as CFC pr hydrofluoroalkane (HFA) — pressurised MDI (pMDI) use in England is responsible for nearly 1 million tonnes of CO2 equivalent per year
where do the lungs get parasympathetic supply from? effect?
- derived from vagus nerve
- stimulates secretion from the bronchial glands, contraction of the bronchial smooth muscle and vasodilation of the pulmonary vessels
where do the lungs get sympathetic supply from? effect?
- derived from the sympathetic trunks
- stimulate relaxation of the bronchial smooth muscle and vasoconstriction of the pulmonary vessels
innervation and blood supply of parietal pleura
- The parietal pleura is sensitive to pressure, pain, and temperature. It produces a well localised pain, and is innervated by the phrenic and intercostal nerve
- The blood supply is derived from the intercostal arteries
innervation and blood supply of visceral pleura
- The visceral pleura is not sensitive to pain, temperature or touch. Its sensory fibres only detect stretch. It also receives autonomic innervation from the pulmonary plexus (a network of nerves derived from the sympathetic trunk and vagus nerve)
- Arterial supply is via the bronchial arteries(branches of the descending aorta), which also supply the parenchyma of the lungs.
what causes respiratory alkalosis?
hyperventilation
O2 and CO2 levels in type 1 vs type 2 resp failure
type 1 = low O2, normal (or low) CO2
type 2 = low O2, high CO2
what causes type 1 vs type 2 respiratory failure?
1 = ventilation/perfusion mismatch
2 = alveolar hypoventilation
causes of type 1 vs type 2 resp failure
1:
- pneumonia
- pulmonary oedema
- bronchoconstriction
- pulmonary embolism
2:
- COPD exacerbation
- opiates overdose/sedation
- rib fractures
- Guillain-Barré syndrome
what is the definition of asthma?
a disease characterised by widespread narrowing of the peripheral airways in the lung, varying in severity over sort periods of time either spontaneously or in response to treatment
why is smooth muscle bigger in asthmatic patients airways?
due to exercise of coughing
what is the effect of cold air and exercise in asthma?
dry out the mucosa of the lung — makes the lining hyperosmolar. causes mast cells to release histamine and prostaglandins, thus causing inflammation
what is the effect of histamine (early mediator) and leukotrienes/PGD2 (later mediators) ?
contraction of airways smooth muscle, increases vascular permeability and increases bronchial secretions
how is asthma diagnosed?
- a history of recurrent episodes of symptoms, ideally corroborate by variable peak flows when symptomatic and asymptomatic
- symptoms of wheeze, cough, breathlessness and chest tightness that vary over time
- recorded observation of wheeze heard by a healthcare professional
- personal/family history of other atopic conditions (especially atopic eczema/dermatitis, allergic rhinitis)
- no symptoms/signs to suggest alternative diagnoses
FEV1/FVC ratio in asthma vs pulmonary fibrosis
asthma - ratio reduced - obstruction
PF - reduced FVC but normal FEV1/FVC
FeNO in asthma?
measure exhaled nitric oxide (FeNO) = inflammatory marker in the airways that can be elevated in patients with asthma. particularly useful in patients with allergic type asthma
describe bronchoprovocation testing
get patients to inhale a chemical that is an irritant of the airways and cause a drop in FEV1 — give them progressively increasing concentrations of this to breathe in through a nebuliser — keep repeating the FEV1 and plot the % fall — if we can make it fall 20% then that is a positive test — suggests the airways are inhaled and irritable and that giving this irritant causes the airways to become twitchy
FVC vs FEV1
FVC = the maximum volume of air that can be forcefully exhaled after a max inspiration
FEV1 = volume of air that is exhaled in the first second of the FVC measurement
FEV1/FVC is reduced in obstructive lung disease, not restrictive (as FEV1 is reduced almost in proportion to FVC)
what are 3 important questions to ask in an asthma annual review?
- in the last month/week have you had DIFFICULTY SLEEPING due to your asthma? (inc cough symptoms, SOB)?
- have you had your usual asthma symptoms (eg. cough, wheeze, chest tightness, SOB) DURING THE DAY?
- has your asthma interfered with you usual daily activities (eg. school, work, housework)?
apart from asthma, what other medical conditions can you hear a wheeze in?
- obstructive pulmonary disease
- foreign body aspiration
- cardiac failure
- eosinophilic lung disease
- COPD
describe vesicular (normal) breath sounds
- normal sound on most of the lung
- soft
- low pitch
- inspiration longer than expiration
- no gap between both phases
describe bronchial breath sounds
- abnormal in majority of lung that is far from main airways
- loud and tubular quality
- high pitched
- inspiratory and expiratory phases
- definite gap between both phases
when are bronchial breath sounds heard?
3 Cs!!
- Consolidation
- lobar Collapse with patent bronchus
- lung Cavity
if bronchial breath sounds are associated with consolidation, what manoeuvres may you be able to elicit?
- increased tactile fremitus
- bronchophony
- aegophony ie. BEE heard as BAY
- whispering pectoriloquy
describe wheeze
- continuous and musical quality
- expiratory usually
- indicates narrowing of airways either due to bronchospasm or secretions in small airways
- low pitch or high pitch
- high pitch polyphonic or monophonic
difference between high pitch or sibilant wheeze to a low pitch or sonorous wheeze
- high pitch or sibilant wheeze are the usual whistling quality wheeze heard due to a smaller airway narrowing in bronchospasm (like in asthma)
- low pitch or sonorous wheeze also called as Rhonchi heard when smaller airways narrow due to secretions (eg. in chronic bronchitis)
high pitch wheeze is usually polyphonic due to what?
variable degree of bronchospasm like in asthma
— more common form we hear in daily practice
when is monophonic wheeze heard?
if there is obstructing pathology in a localised area
describe cacles/crepitations
- interrupted and non-musical quality
- inspiratory usually
- peripheral airway collapse on expiration due either to interstitial fibrosis or secretions/fluid
- during inspiration, rapid air entry abruptly opens these collapsed smaller airways and alveoli producing crackling noise
when are early inspiratory crepitations heard?
in small airway disease like broncholitis
when are mid inspiratory crepitations heard?
pulmonary oedema
when are late inspiratory crepitations heard?
pulmonary fibrosis, pulmonary oedema, COPD, resolving pneumonia, lung abscess, tuberculous lung cavities
when are biphasic crepitations heard?
bronchiectasis
when are fine crepitations heard?
broncholtiis, pulmonary oedema, pulmonary fibrosis
when are coarse crepitations heard?
COPD, resolving pneumonia, lung abscess, tuberculous lung cavities or bronchiectasis
what is pleural rub most commonly caused by?
an inflammation of either the visceral and/or parietal pleura
CRB-65 score
CURB65 score
severity score to estimate mortality of CAP
1 point for each feature present:
- Confusion
- Urea greater than 7 mmol/l
- Respiratory rate of 30 breaths/min or more
- Blood pressure (Systolic less than 90 mmHg or diastolic of less than 60 mmHg)
- Age 65 years or greater
How would you differentiate between an effusion and consolidation radiologically?
Both produce opacification of the lung field.
- In consolidation, the margins of opacification are not clear as compared to effusions.
- In effusions the opacification is dense and there are no markings visible in the lung field. In consolidation you can see air bronchograms, so the opacification is not dense.
- The diaphragm / costo-phrenic and cardio-phrenic angles are not visible in effusions. While these may still be visible in consolidation depending on areas of lung affected.
