Resp Flashcards
Can you
explain how proteolytic enzymes function in the normal lung?
Alpha1-antitrypsin inhibits neutrophil elastase, a proteolytic enzyme
capable of destroying alveolar wall connective tissue. Alpha1-antitrypsin
deficiency allows damage to occur to distal lung tissue with the
development of emphysema. Neutrophil elastase is the most abundant
antiprotease in the lung and as smoking stimulates elastase release, lung
tissue damage occurs leading to worsening emphysema.
Bronchiectasis is given as one of the causes of bronchial breath sounds.
This is difficult to comprehend. Could you explain the mechanism of
bronchial breath sounds more clearly?
In bronchial breathing, the expiratory sound of breathing is louder on
auscultation. In bronchiectasis due to collapse, dilatation and sometimes
consolidation, the sounds are transmitted more directly through to the
chest wall with little lung tissue to filter out the higher frequencies which
are also characteristic of bronchial breathing.
I have been taught to examine vocal resonance by asking the patient to
say ‘ninety-nine’ while auscultating. I listen for a louder ‘ninety-nine’
over an area of consolidation and more quiet sounds with effusion.
Is this right?
Consolidation allows the transmission of higher frequencies, which
makes sounds like ‘ninety-nine’ clearer and often louder. Different
countries have words of similar frequency to demonstrate this.
A pleural effusion decreases transmission of all breath sounds of
whatever frequency and therefore little or no sound is heard.
What role does bupropion play in giving up smoking?
National Institute of Health and Clinical Excellence (NICE) UK
guidelines state that nicotine replacement therapy or bupropion should
only be used for the smoker who ‘commits’ to a stop date. Advice and
encouragement to stop smoking should be offered. Both treatments
are effective aids to stopping smoking; there is no evidence for their
combined use.
The clinical signs and symptoms of rhinitis are very similar to those of
the common cold (influenza). How do I differentiate between the two?
Colds clear up within 1 week; rhinitis persists, being either seasonal or
perennial.
Influenza is different from a cold. With a real episode of influenza the
systemic effects of a temperature and muscle aches usually confine the
patient to bed.
What is the advantage of the drugs des-loratidine and levo-cetirizine
over their parent compounds? Are they safe in pregnancy and lactation?
Des-loratidine and levo-cetirizine are not available in the UK. Loratidine
and cetirizine themselves are not teratogenic but loratidine is excreted in
breast milk. To be on the safe side, no drugs should be used in pregnancy
if possible
What are the differences between acute bronchitis and pneumonia? Are
both diseases caused by infection?
Acute bronchitis is literally inflammation of the bronchi; it is usually
viral in origin. Pneumonia is inflammation of the lung substance and is
most commonly due to bacteria; over 50% being due to Streptococcus
pneumoniae.
If a patient with chronic bronchitis develops obstructive jaundice
and Escherichia coli biliary sepsis, should the routine administration
of oral steroids (e.g. prednisolone) be suspended until liver function
improves?
Are there any adverse reactions that preclude the concurrent use of
steroids while the patient is treated with IV ciprofloxacin, gentamicin,
metronidazole and cefuroxime?
No, in such a sick patient steroid therapy should be continued,
otherwise he or she will develop acute adrenal insufficiency, assuming
that the patient has been on steroids for a long time.
No, there are no adverse reactions precluding the concurrent use of
steroids.
there is actually a situation in which the FVC in COPD patients might
increase?
In COPD there is a reduction in the forced vital capacity (FVC) with a
relatively greater reduction in forced expiratory volume (FEV1).
Is there any obstructive pulmonary condition in which there might be an
increase in FVC? If so by what mechanism?
No; an obstructive pattern always reduces FVC.
I am confused whether clubbing is a feature of chronic obstructive pulmonary disease (COPD) or not – you have mentioned that it is not a feature of COPD but some books do say that clubbing is a clinical feature of COPD.
Clubbing does not occur in COPD. In a patient with COPD and clubbing,
one would wonder whether a carcinoma of the bronchus, or bronchiectasis
for example, were also present.
A 70-year-old man with chronic obstructive pulmonary disease (COPD)
and a past history of myocardial infarction with a left ventricular ejection
fraction (LVEF) of 25% is dyspnoeic on slight exertion such as walking,
bathing. He is not orthopnoeic and claims to have no paroxysmal
nocturnal dyspnoea (PND). He has no wheezing or productive cough and
his blood pressure is normal. He has had three episodes of ventricular
tachycardia (VT) and has been on amiodarone for the past year. What is
the best way to determine the exact cause of dyspnoea in this case?
Examination of the patient is helpful. Tachycardia, raised venous
pressure, third and fourth heart sounds and basal crackles indicate
cardiac failure. Chest wheezes suggest bronchospasm, and cough with
sputum is more often seen in COPD. Exercise tests are helpful, as is the
measurement of serum brain natriuretic peptide (BNP). A normal plasma
level of BNP excludes heart failure. Response to therapy is often the best
guide.
In bronchiectasis, what is the reason for using a bronchodilator if the
airways are already dilated?
There is a small element of bronchospasm, but the effect is small.
Why is it that asthmatics having a severe attack can be seen clawing their
hands?
There is no good reason for this but patients are very often anxious and
this is the probable reason for them clawing their hands.
Practical use of steroids:
● Which form of regimen is better (alternate-day, daily or in pulse form)?
● What should be the dose (once daily or three times daily or {2/3} in
the morning)?
● For how long, especially when to give short courses as in asthmatics,
when we don’t need to taper it down?
No regimen of steroid usage is the best. Alternate-day administration has
not been successful in asthma because patients can deteriorate during the second 24 hours. There is certainly no need to give therapeutic steroids
more than once daily except when initiating steroids for acute severe
asthma. As with all drugs, it is best to get to know how to use the drug
by seeing many patients.
In pregnancy, what is the recommended treatment for bronchial asthma?
Is the use of the long-acting beta-adrenergic agonist Seretide, the
corticosteroid Symbicort and leucotriene receptor antagonists (LTRAs)
recommended?
Asthma must be well controlled during pregnancy and drugs should be
given by inhalation to minimize exposure to the fetus. All drugs appear
safe by inhalation. In acute attacks, parenteral steroids are safe and
you should always keep the mother’s oxygen saturation above 95% to
prevent fetal hypoxia.
In asthma patients, which is the safest analgesic to use?
Paracetamol
Is the use of nebulized heparin in the treatment of asthmatic attacks
recommended?
no
I would like to ask you about pneumonia and its classifications in
particular; what are they?
1. Clinical: ● Primary: ● community acquired ● hospital acquired. ● Secondary: ● immunocompromised patients ● aspiration pneumonia
- Aetiological: classified by infecting agent
The most common are: Streptococcus pneumoniae (50%),
Mycoplasma spp. (6%), Haemophilus influenzae (5%)
3. Anatomical: ● Lobar. ● Segmental. ● Subsegmental. ● Bronchopneumonia
What are the pathological differences in typical and atypical pneumonia?
typical pneumonia due to pneumococcus is:
● congestion
● red hepatization
● grey hepatization
● resolution.
The details of these are available in many books of pathology.
We dislike the term ‘atypical’ because it accounts for 20% of all
pneumonias. The pathology in this group is not well described because
very few patients die.
Why, sometimes in cases of aspiration pneumonia, would the level of
lymphocytes drop below normal range while the level of white blood
cells (WBC) and neutrophils are above normal range?
unusual for the level of lymphocytes to drop below the normal range
in aspiration pneumonia but obviously the total number of WBC and
neutrophils do increase as a result of infection
Should steroids be used in the treatment of a standard case of pneumonia
in a young child?
no
