Respiratory Flashcards
How is the severity of pneumonia assessed?
CURB 65
Other than a high CURB 65 (>2) what are signs of severe pneumonia?
1) Hypoxaemia
2) Lots of consolidation on CXR
3) Co-morbidities
4) Evidence of cavitation
Remind me of CURB 65 criteria?
1) New confusion
2) Urea >7
3) RR >30
4) BP <90 or <60
Management of CURB 0-2 ?
Community mainly
Amoxicillin 1g TDS PO for 5 days
(Doxy - 200mg loading dose then 100mg daily)
(Patients with CURB 1/ 2+ adverse prognostic factors may need hospital +/- IV)
Management of patient with a CURB 65 of 3+ managed on ward 3?
Severe pneumonia
Co-amoxiclav 1.2g TDS IV
Doxycycline 100mg BD
(Penicillin allergy = 500mg BD)
Management of patient with a CURB score of 1/2 who is penicillin allergic and needs IV therapy/
IV clarithromycin
(Doxycycline is not given IV)
IVOST to amoxicillin 1g TDS
Management of a patient with CURB 4 in HDU?
Co-amoxiclav 1.2g TDS IV
Clarithromycin 500mg BD
7 days treatment
IVOST to doxycycline
Management of a patient with CURB 65 of 4 who has a penicillin allergy?
Levofloxacin IV 500mg BD
Will need total 7 day treatment
IVOST to doxycycline
What discharge advice should people with pneumonia be given?
1) Stop smoking
2) Follow up CXR at 6 week if smoker/ >50
Adult with new diagnosed asthma. What regular therapy is first line?
1) SABA as required
2) ICS typically 400micrograms
An asthmatic patient is on a SABA and 400 micrograms of ICS daily but is still symptomatic. Next step?
Add a LABA then assess control
Good = continue LABA
OK = continue LABA and increase ICS to 800mcg daily
No response = Stop LABA, increase ICS to 800mcg daily and consider trial e.g. LTRA or theophylline
Asthmatic patient on SABA, 800mcg ICS and LABA. Control is still poor, next step?
Consider increasing steroid to 2000mcg daily
AND/OR add in a 4th agent e.g. LTRA or theophylline or oral B2 agonist such as terbutaline
What is the final step in the asthma pathway?
Lowest dose of oral steroids to give good control
Refer to respiratory specialist
What is a moderate asthma attack?
Worsening symptoms
PEFR 50-75% of predicted
What is a severe asthma attack?
PEFR <50% of predicted
Inability to complete sentences
RR >25 or HR >110
RR and HR that equate to a severe asthma attack
RR >25
HR >110
Feature of a life threatening asthma attack?
PEFR <33% SP02 <92% PA02 <8 Silent chest Cyanosis Exhaustion Reduced conscious level Hypotnesion
What defines a near fatal asthma attack?
Raised paCO2
Requiring ventilation!
How many lobes do the lungs have?
Right = 3 Left = 2
Name some accessory muscles of inspiration?
Scalene and SCM
Which muscles are predominately involved in forced expiration?
Abdominal
Tidal breathing is a balance between what 2 forces?
1) Chest wall - semi-rigid which wants to expand
2) Lung - which want to collapse inwards
E.g. Normal = stretching a neutral spring, Lung disease = stretching a spring already under tension
What is lung compliance?
The change in lung volume brought about by a unit change in intra-pleural pressure e.g. the force needed to expand the lung
At the lung bases perfusion exceeds ventilation
At the lung apices, ventilation exceeds perfusion
remember that vasoconstriction occurs in response to poor blood flow
What is the result of a fall in ventilation?
A rise in CO2 and a fall on O2
E.g. type 2 respiratory failure
What is the result of a mismatch in V/Q?
Type 1 respiratory failure e.g hypoxia without hypercapnia
What are the main stimulants of ventilation?
Controlled by respiratory centre in the brain which is stimulated by pH and CO2 levels
Hypoxia is only a stimulant when PO2 <8kPA
What is the tidal volume?
Volume of air that enters and leaves lungs during normal breathing
What is the functional lung capacity?
Volume in lungs at end of normal expiration
What is the total lung capacity?
Volume in lungs after maximal inspiration
Residual volume
Volume in lungs after maximal expiration
What is vital capacity?
Volume of air moved in full inspiration and expiration
Describe an obstructive pattern?
FVC is reduced but FEV1 is reduced more therefore FEV1: FVC = <70%
Describe a restrictive pattern?
Both FVC and FEV1 are reduced proportionately therefore FEV1:FVC ratio is normal e.g. >70%
What does FEF 25-75 measure?
Flow during middle half of forced expiration e.g. in the medium sized airways
What causes a lung collapse?
Obstruction of bronchus due to:
1) Tumour
2) Foreign body
3) Mucus plug
R upper lobe collapse?
Golden s sign
Increased density in RUL
Clear horizontal fissur e
R middle lobe collapse?
Poor definition of R heart border
Horizontal fissure difficult to see
R lower lobe collapse
Increased opacity (triangle) at medial base of R lung
R hilum depressed
R hemidiaphragm elevated
L upper lobe collapse?
Falls inferiorly
Hazy over the hilum, becomes less hazy inferiorly.
L lower lobe collapse
Triangular opacity at psteromedial aspect of left lung
Double cardiac contour
‘Sail sign’
What does the blood film of someone with EBV show?
Atypical mononuclear cells
(Also do monospot/ heterophile anti-body +ve
Features of sinusitis?
Facial pain
Nasal obstruction
Nasal discharge
Fever
What is ephedrine?
A nasal decongestant
sympathomimetic drug
Organism in whooping cough?
Bordetella pertussis
How do you diagnose flu?
Clinical features e.g. systemically unwell, URTI etc
Immunofluorescent microscopy of nasal secretions/ serology
What is oseltamivir?
A drug that reduces the replication of influenza A and B virus - it is used to reduce duration of flu symptoms
(only by about 1 day)
The flu vaccine is CI to patients with severe egg allergy
The flu vaccine is CI to patients with severe egg allergy
remember that even if you get flu after having the vaccine it is likely to be less severe with fewer complications
What is a Ghon focus?
The primary lesion of TB
Usually sub-pleural in the mid to lower zones - often in children
(a dot of consolidation
What is the difference between primary and post-primary TB?
Primary = first infection in patient without TB immunity
Post-primary = pattern of disease seen after specific immunity (can occur from progression, reactivation or re-infection)
Cavitating apical lesions on CXR
TB is most likely
Ask about cough, sputum, haemoptysis, weight loss and sweats
Diagnosis is with sputum culture for acid and alcohol fast bacilli
Caseating granuloma is characteristic of TB
What is the current treatment regime for TB?
6 months of rifampacin and isoniazid
With pyrazinamide and ethambutol for the first 2 months
Dispensed daily or with directly observed therapy
Side effects of rifampacin?
Hepatitis - check LFT at start
Enzyme inducer - reduces effect of warfarin and the pill etc
Makes pee red (good for checking compliance)
Side effect of isoniazid?
Peripheral neuropathy (pyridoxine is given to high risk groups e.g. DM)
Hepatitis
Side effect of pyrazinamide?
Increase in uric acid —> gout
Side effect of ethambutol?
Optic neuritis
Check visual acuity before treatment and stop if any visual problems
Summarise the pathogenesis of bronchiectasis
Impaired mucociliary clearance > infection > inflammatory response > tissue damage > bronchial damage and dilatation
What is Kartagners syndrome?
Ciliary dyskinesia with situs invertus (appendix in LIF)
Give some causes of bronchiectasis?
Severe Infection - measles, pertussis, pneumonia, TB
Obstruction - foreign body/ carcinoma
CF
Ciliary dysfunction
Features of bronchiectasis
Chronic cough with copious sputum production
Possibly haemoptysis and frequent infection
What is the best investigation for diagnosing bronchiectasis?
CT
Consider cause e.g. check immunoglobulin, ciliary function, TB etc
Which drug should be used to treat Pseudomonas infection?
Ciprofloxacin
(2 week course)
Pseudomonas infection is a bad prognostic indicator
Management of bronchiectasis
1) Chest physio
2) Use mucolytics such as nebulised saline (with bronchodilator)
3) Antibiotics (to treat infections)
4) surgery (excision of particular lesion or transplant)
How common is CF?
1 in 25 are carriers
1 in 2500 are affected
Why does CF cause abnormalities in the GI tract?
Abnormal ion transport causes the ducutules within the pancreas to become blocked —> enzymes not being able to pass —> malabsorption
There is increased risk of DM, gallstones and biliary cirrhosis
What is the main reason that kids with CF are not allowed to spend time together?
Risk of infection and transmission of Burholderia strains, especially Burholderia cenocepacia which can cause a rapid decline in lung function
If a diagnosis of meconium ileus is made, what is the most likely underlying cause?
CF
How is CF diagnosed?
Elevated Na in the sweat test (using pilocarpine)
Then look for specific CF mutation on DNA analysis
Why are males with CF infertile?
Congenital absence of the vas deferns
The newborn screening test is used to test for CF. What are they testing for?
Increased immunoreactive trypsin activity
What are mucolytic medications?
Treatments which help aid mucus clearance
1) Dnase- cleaves DNA, give via nebuliser
2) Hypertonic saline - given with salbutamol
3) Mannitol - osmotic
What is the life expectancy for a patient with CF?
Median age of death is now 44 - this has improved hugely due to advances in all aspects of medicine
What is Ivacaftor?
A gene therapy drug used in the management of CF patients with a class 3 mutation It increase the action of the CFTR channel and improves lung function and weight gain
Define asthma
Airway inflammation
Increased airway responsiveness
Reversibility
Variability
How are T cells linked to asthma?
Th2 cells produce pro-inflammatory cytokines
Th1 cells produce cytokines that down regulate the immune response
In asthma, Th2 cells are likely to predominate
Describe the pathology of asthma
Airway thickening and oedema Increased smooth muscle mass Thickened basement membrane Remodelling of the airway Mucus plugging (in acute, severe asthma)
What are the core symptoms of asthma?
Cough
Wheeze
SOB
Chest tightness
How does peak flow vary throughout the day?
Classically there is a ‘morning dip’
What are key features of the asthma history?
1) Symptoms - nocturnal wakening etc
2) Family History (and of atrophy)
3) Environmental history - smoking, pets
4) Work environment
5) Triggers
Spirometery diagnosis of asthma
1) Obstructive pattern (ratio <70%)
2) Reversibilty - give a bronchodilator drug and see if they improve
Total lung capacity is increased in asthma as a result of hyper-inflation
Residual volume is also increased as a result of gas trapping
Why is a normal CO2 worrying in an acute severe asthma attack?
Normally hypoxia will develop, associated with increased ventilation and a reduced CO2. A normal (or rising) CO2 is a sign of a fatigued patient who is failing to maintain ventilation
What are the 2 types of stress test that can be used to diagnose asthma?
1) Exercise testing - does peak flow fall by >25% after exercise
2) Histamine challenge
Remember that SABAs are good for symptom control but they do NOTHING to address the underlying inflammation
Salbutamol and terbutaline have the side effects of tremor and palpitations at high doses
SABA have an onset of action within 15 minutes and are effective for 4-6 hours
LABAS have a slower onset of action but are effective for 12 hours
(normally green inhalers but combination inhalers are purple)
What is the mechanism of action of theophyllines?
Drugs such as aminophylline/ theophylline increase cAMP by inhibiting the metabolism of cAMP. Not used widely and are generally the ‘last resort’ for steroid sparing agents.
It’s really important when counselling patients to remind them that the blue inhaler will help with their symptoms
The brown inhaler will help reduce the inflammation and stop them getting symptoms
What is ‘resucue’ prednisolone?
A 7 day course of 30-40mg prednisolone PO which is given when asthma symptoms are increasing e.g. when PEFR <60% of expected
To be used infrequently
Who will benefit from treatment with Omalizumab?
Patients with severe allergic asthma
It is a monoclonal antibody that binds to IgE
How do you use a pressurised metered dose inhaler?
1) remove cap and shake
2) Exhale
3) Place mouth on inhaler and fully inhale while pressing down on the canister
4) Hold breath for a few seconds
(remember that without a spacer, only about 10% of the drug reaches the lower airways
What should the nebuliser flow rate be set too?
6-8l/ min
Managment of acute severe asthma?
1) High flow O2
2) Salbutamol nebuliser - 5mg
3) Hydrocortisoe 100mg IV or prednsiolone 40-50mg PO
If poor response consider adding the following:
4) Nebulised ipratroprium bromide - add 0.5mg to the nebulised salbutamol
5) Magensium/ aminophylline = only if agreed by senior medical staff