Case 3 Flashcards
what is COPD a combination of
bronchitis and emphysema
what is bronchitis
cough and sputum production on most days for at least three moths during the last two years
what is emphysema
enlarged air spaces distal to the terminal bronchioles with destruction of the alveolar walls
is there any reversibility with COPD obstruction
no
from 1-10 how leading is COPD as a cause of death
4th leading cause of death
percentage of smokers who will develop COPD
10-20%
what deficiency causes emphysema
alpha 1 anti tyrpsin
percentage of adult population it affects
1-4%
how many causes in UK - diagnosed and undiagnosed
3 million undiagnosed, 1 million diagnosed
how many deaths per year in UK
30,000
odds of hospital admissions
1 in 8
symptoms
breathlessness
cough
regulat exacerbations
some unusual signs
- use of accessory muscles during respiration
- reduced cricosternal distance
- pursed lip breathing
what does gas trapping lead to
increase in dead space and hyperinflation
what is FVC
forced vital capacity
what Is the predicted FVC value
<80%
what is the FEV
forced expiratory volume
what is value of FEV/FVC ratio
<0.7
what is bullae
complications of emphysema. Air pockets grow, take up space in the chest cavity and encroach on the heart
what can the heart look like in a COPD chest X-ray
cylindrical
what would readings on an ECG show
right atrial and ventricular hypertrophy, leading to large P waves
what would an ABG test show
decreased PaO2
increased PaCO2
how is COPD diagnosed
through spirometry
are there any clinical features of this diagnosis
no
what is FEV value for severe COPD
<40%
why is there a hyper secretion of mucus
due to marked hypertrophy of mucus-secreting glands and hyperplasia of goblet cells. also reduces lumen size and increasing distances for gas diffusion
when is the process irreversible
when the larger airways become infected
what is main cell involved in chronic bronchitis
the main cell involved is the neutrophil
what are the two main kinds of emphysema
centrilobular - associated with smoking
pan lobular - inherited
what are the three main pathological effects of COPD
- loss of elasticity of the alveoli
- inflammation and scarring - reduces the size of the lumen as well as reducing elasticity
- mucus hyper secretion - reducing the size of the lumen and increasing the distance gases have to diffuse
what do tobacco products release from white cells
predominantly neutrophil polymorphs
what does tobacco inhibit
alpha 1 antitrypsin
what is pulmonary fibrosis
- loss of type 1 pneumocytes
- replaced by type 2 pneumocytes - failure of normal maturation
- excessive deposition of collagen
which disease is finger clubbing associated with
pulmonary fibrosis
how common is lung cancer
second most common cancer diagnosed in the UK after breast cancer
what are the histological classifications of primary lung cancer
- squamous cell carcinoma
- small cell carcinoma
- adenocarcinoma
- large cell undifferentiated carcinoma
what is an exacerbation of COPD
defined as a change in the patients baseline symptoms such as;
- worsening SOB
- increase cough
- increase sputum
what does goblet cell hyperplasia lead to
cough and sputum
what does airway narrowing lead to
breathlessness and wheeze
what does alveolar deconstruction lead to
breathlessness
normal FEV/FVC ratio
70-85%
what is pulmonary rehabilitation
multidisciplinary programme of care for people with chronic respiratory impairment. it is individually tolerated
who do NICE recommend making pulmonary rehabilitation available to
everyone with copd
what does pulmonary rehabilitation include
- physical training
- disease education
- nutritional education
- physical and behavioural intervention
after 20 mins
pulse returns to normal
after 8 hours
nicotine is reduced by 90% and carbon monoxide levels in blood reduce by 75%. circulation improves
after 24 hours
carbon monoxide and nicotine removed from the body. ability to taste and smell improves
after 72 hours
breathing is easier. bronchial tubes begin to relax and energy levels increase
2-12 weeks
circulation improves
1 month
physical appearance improves
3-9 months
coughing and wheezing is reduced
1 year
excess risk of a heart attack reduces by hand
10 years
risk of lung cancer falls to about half of a continuing smoker
after 15 years
risk of a heart attack falls to the same as someone who has never smoked
what is pneumonia
infection of the lung interstitium, alveoli and airways
what does CAP, HAP AND VAP stand for
CAP - community acquired pneumonia
- HAP - hospital acquired pneumonia
VAP - ventilatory acquired pneumonia
how many pneumonia’s require hospitalisation
1 in 3
what is tachypnoea
hast breathing
what is tachycardia
fast pulse
what is the treatment for acute bronchitis
supportive only unless prolonged illness
treatment for ‘exacerbation’
- bronchodilators
- steroid
- oxygen
treatment for pneumonia
PROMPT antibiotics. must cover streptococcus
treatment of COVID 19
- antivirals - remdesivir
- anti inflammatioies - tocilxumab
when does a lung infection become chronic
lasts more than 6-8 weeks
transfer is proportional to
- pressure gradient
- surface area available for diffusion
- 1/length of the pathway
- solubility
- 1/(square route) molecular wight
what is the resting cardiac output
5L/min
what scale measures severity of dyspnoea
MRC dysponaie scale
COPD management in community
- bronchodilators
- antibiotics
- oral corticosteroids
hospital management of COPD
ABC assessment
controlled oxygen therapy
blood gas measurement
CXR
what is addiction
an inability to stop using a substance or engaging in a behaviour even though it is causing psychological and physical harm
what does nicotine exert their actions by elevating
the synaptic levels of dopamine, noradrenaline and serotonin
what is the serotonin pathway called
the dopamine reward pathway
mode of action of nicotine
- nicotine enters the brain, stimulating the release of dopamine inducing nearly immediate feelings of pleasure
- initiates acetylcholine and binds to the nicotinic receptors and mimics the action of Ach
- body increases levels of Ach to all unregulated stimulation
- heightened activity in cholinergic pathways to the brain
what is the second transmitter nicotine stimulates and describe
- stimulates release of glutamate
- it is involved in the learning and memory and enhances the connections between sets of neurone
- these stronger connections may create a memory loop of the good feelings you get and further drive the desire to use nicotine
how does smoking affect the lungs
- toxins break the thin walls of the alveoli leaving larger, less efficient air sacs
- they also lose their bounce making it harder to exchange oxygen
- signals the start of emphysema
how does smoking make you cough
-
- cells that produce mucus in your lungs and airways grow in size and number so amount of mucus increases and thickens
- lungs can’t clean out this mucus and makes you cough
what does black mucus indicate
fungal infection
what does rust coloured sputum suggests
pneumococcal infection
how does amoxicillin work
interfere with ability of bacteria to form cell walls
- impaired the bonds that hold the bacterial walls together and allows holes to appear and kills the bacteria
action of cefuoxime
- attaches via B lactan ring to the target in the cell (penicillin binding protein)
- changes the functional group of the protein on the cell wall and uses inhibition of the transpeptidation enzyme that cross links the peptide chains attached to backbone of the peptidoglycan
- as cell wall grows in coordination with bacterial growth, the cell wall is weakened and crumbles. extracellular fluid enters and leads to the death
what is the enzyme bacteria can produce to stop penicillin working
B-lactamase
what is cefuroxime used to treat
pneumonia
what bacteria is pneumonia caused by
pneumococci
COVID mechanism
- uses the human ACE2 receptor for viral entry and cell tropism for infectivity
- infection of circulating immune cells is abortive
- viral structural spike protein that binds to ACE2 receptor
- the type 2 transmembrane serine protease present in the host cell, promotes viral uptake by cleaving ACE2 and activating the s protein
what are the host cells for COVID
alveolar epithelial type II cells
what is scarring called in lungs
pulmonary fibrosis
how do anticholinergic bronchodilators work
- bind to muscarinic receptors and block action of acetylcholine
- reduce the bronchomotor tone which leads to bronchodilator
what is the drawback from using a combination inhaler
loss of flexibility in dosing of component drugs in the inhaler
how long does it take nicotine to reach the brain
10 seconds
what is 2,3-BPG
molecule that binds to haemoglobin and decreases its affinity for oxygen
what role does Hering Bruer reflecx play in breathing
terminates inspiration to stop inflammation of the lungs
a pink puffer does not have what symptom
cyanosed skin
what is mechanism of action of clarithromycin
binds to 50 s subunit of bacterial ribosome and inhibits translation of peptides
what happens to PEFR value
it is low
what happens to blood gases in severe COPD
hypoxemia and hypercapnia
what is aim of oxygen therapy
to increase Pa02 to at least 8kPa (60mmHg)
what percentage of oxygen is usually administered
24-28%
who does centrelobular emphysema affect
smokers
who does pan lobular emphysema affect
alpha 1 antitrypsin deficient
what is distal acinar (paraseptal) emphysema
- underlies many of the cases of spontaneous oneumotharox
what cells are increased in the lung
macrophages, CD8+, CD4+ T lymphocytes and neutrophils
what is alpha 1 antitrypsin
is it a proteinase inhibitor which is produced in the liver, secreted into the blood and diffuses into the ling
- it inhibits proteolytic enxymens such as neutrophil elastase which are capable of destroying alveolar wall connective itusse
what do neutrophils and macrophages activate
the transcription factor NF-xB which switches on genes that encode TNF and chemkines
what is hyperaemia
excess of blood in vessels
what kind of bacteria is streptococcus pneumonia
gram positve
what type of bacteria is HAP
gram negative
what are the four stages of substance use
- initiation
- maintenance
- cessation
- relapse
what is varenicline
partial agonist of the alpha 4 beta 2 subtype of the nicotinic acetylcholine receptor. stimulates receptors more weakly than nicotine. does not greatly increase downstream release of dopamine.
eryhtromycin mechanism
- macrolides inhibit bacterial protein synthesis by an inhibitory effect on translocation
where do macrolide antibiotics bind to
the P site on the submit 50s of the bacterial ribosome. considered bacteriostatic
