Week 6 - Asthma Flashcards
how many lobes does the right lung have?
3
what are the fissures in the right lobe?
oblique fissure (between inferior lobe and superior + middle lobes)
horizontal fissure (between superior and middle lobes)
what are the superficial markers of the oblique fissure of the right lung?
begins roughly at the spinous process of the vertebra TIV level of the spine, crosses the fifth interspace laterally, and then follows the contour of rib VI anteriorly
what are the superficial markers of the horizontal fissure?
follows the fourth intercostal space from the sternum until it meets the oblique fissure as it crosses rib V.
what is adjacent to the medial surface of the right lung?
heart,
▪ inferior vena cava,
▪ superior vena cava,
▪ azygos vein, and
▪ esophagus.
how many lobes does the left lung have?
2
what are the superficial markers of the oblique fissure of the left lung?
marked by a curved line on the thoracic wall that begins between the spinous processes of vertebrae TIII and TIV, crosses the fifth interspace laterally, and follows the contour of rib VI anteriorly
what is the lingula in the lungs and where is it?
From the anterior border of the lower part of the superior lobe a tongue-like extension (the lingula of the left lung ) projects over the heart bulge.
what spinal levels does the trachea run from and to?
C6-T4/5
when does the trachea bifurcate?
C4/5
what is the carina?
bifurcation of the trachea
what are the shapes of the right and left main bronchi?
right = wider and more verticle
left = thinner and more horizontal
which lung are inhaled foreign bodies found?
right
what do the main bronchi branch into?
lobar bronchi
what are secondary bronchi?
lobar bronchi
what do the lobar bronchi branch into?
segmental bronchi
what are segmental bronchi also known as?
tertiary bronchi
how many bronchopulmonary segments are there in each lung?
10
what cells line the trachea?
pseudostratifies columnar ciliated epithelium
which part of the bronchial tree contains goblet cells?
trachea and upper bronchi
what are the features of the terminal bronchioles?
simple columnar epithelium
initially cilliated
no goblet cwlls
what are the features of the respiratory bronchiole?
ciliated cuboidal epithelium
what are the features of the alveoli?
squamous epithelium
type 1 pneumocytes = thin diffsuion barrier for gas exchange
type 2 pneumocytes = secrete surfactant which decreases surface tension and stops alveolar collapsing
what are type 1 pneumocytes?
involved in gas exchange in the alveolar
thin wall
what are type 2 pneumocytes?
secrete surfactant whcih decreases the surface tension so alveolar dont collapse in exhalation
what is the function of the conduction region in the lungs?
- Conducting portion (nose, pharynx, larynx, trachea, bronchi and bronchioles) → serve to humidify, warm and filter air
○ Humidification → requires serous and mucous secretions
○ Warming → relies on the extensive capillary network that lays within alveoli
○ Filtration → occurs by trapping mechanism of mucus secretions and ciliary beating
§ Goblet cells → columnar epithelial cells that secrete high molecular weight mucin glycoproteins into the lumen of the airway and provide moisture to epithelium while trapping incoming particulate and pathogens
what is the blood gas barrier? name each step the O2 goes through to get to the blood
Type 1 alveolar cell -> basement membranes -> endothelial cells of capillary wall -> blood from pulmonary arteries
where is the respiaratory centre of the brain? how does it send signals to the resp muscles
pons and medulla
send impulses to primary resp muscles via phrenic and intercostal nerves
what do the ventral, dorsal and pontine areas control in ventilaiton?
- Ventral: expiration
- Dorsal: inspiration
Pontine: rate and pattern of breathing
what happens when
peripheral chemoreceptors detect low O2?
impulses travel through glossopharyngeal and vagus newver to medulla oblongata and pons
Brainstem then causes
1. Respiratory rate,tidal volume, and cardiac output to increase
2. Blood flow directed to kidneys and brain
what do central chemoreceptors detect?
partial pressure of co2
what medications are classed as relievers in asthma?
sabas
e.g. salbutamol
what medications are classed as preventers in asthma?
ICSs
e.g. beclamethosone
what are leukotrine receptor antagonists? give an example?
montelukast
Leukotrienes are produced by the immune system and cause inflammation, bronchoconstriction and mucus secretion in the airways. Leukotriene receptor antagonists work by blocking the effects of leukotrienes
what is theophylline?
This works by relaxing bronchial smooth muscle and reducing inflammation. Unfortunately it has a narrow therapeutic window and can be toxic in excess so monitoring plasma theophylline levels in the blood is required. This is done 5 days after starting treatment and 3 days after each dose changes.
what are some side effectts of anti-inflammatory drugs?
· Dysphonia (effect of voice box, altered voice)
· Oropharyngeal candidiasis
· Adrenal suppression
· Osteoporosis
hyperglycaemia
what is the aim of asthma treatment?
§ No daytime symptoms
§ No night-time awakening due to asthma
§ No need for rescue medication
§ No asthma attacks
§ No limitations on activity including exercise
§ Normal lung function (FEV and/or PEF >80%) predicted or best
Minimal side effects from medication
what is the stepwise management of asthma?
SABA required at all steps
- regular preventer (low dose ICS)
- initial add-on therapy (add inhaled LABA to low dose ICS)
- additional controller therapies (increase ICS to medium dose/add leukotrine receptor antagonist)
if LABA isnt working from previous step them stop it - specialist therapies
what is classed as a moderate acute asthma exacerbation?
increasing symptoms
* PEFR 50 – 75% predicted
Speaking full sentences
what is classed as a severe asthma attack?
any one of these:
PEFR 33-50% predicted
Resp rate >25
Heart rate >110
Unable to complete sentences in one breath
what is classed as a life-threatening asthma attack?
PEFR 33-50% predicted
Resp rate >25
Heart rate >110
Unable to complete sentences in one breath
what is classed as a near fatal asthma attack?
raised PaCO2 and/or requiring mechanical ventilation with raised inflation pressures
patient has PEFR of 50-75% of best? is this an asthma attack and if so what type?
moderate acute asthma attack
what PEFR indicates a severe asthma attack?
33-50% of best
what PEFR indicates a life threatening asthma attack?
<33% of best
how is a moderate acute asthma attack treated?
Treated at home or in primary care
Admit people with a moderate asthma exacerbation with worsening symptoms despite initial bronchodilator treatment and/or who have had a previous near-fatal asthma attack.
SABA 2.5mg to be repeated x2 over 60mins if requires
nebulised ipratropium bromide (250-500ug 3-4 times a day)
