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Respiratory system 2017 > Cystic fibrosis > Flashcards

Flashcards in Cystic fibrosis Deck (40)
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1
Q

What is the gene prevalence of cystic fibrosis in Europe?

A

1:25

2
Q

What is the disease prevalence of cystic fibrosis in Europe?

A

(1:25 x 1:25) x 4 = 1:2500 will have CF

3
Q

Describe the inheritance of CF

A

Autosomal recessive

4
Q

Describe the mutation associated with CF

A

Autosomal recessive mutation on q arm of chromosome 7 for the CF transmembrane conductance regulator (CFTR)

5
Q

What is the most common deletion associate with CF

A

phe508del - codon deletion leads to improper folding of protein and it can not leave the ER to be presented on the surface and is instead recognised as faulty and destroyed

Seen in 70% of Northern European CF patients

6
Q

How does CF affect the CFTR?

A

Can affect function or the levels of surface expression of the CFTR

7
Q

What is the function of CFTR?

A

Active transport for chloride out into the mucus, regulating the liquid volume on epithelial surfaces/in the mucus

In CF, there is reduced Cl efflux and increased Na influx, leading to the development of thick mucus, hard to cough up

8
Q

Describe neonatal screening for CF

A

Guthrie heel prick - day 5, CF and PKU

Immunoreactive trypsinogen levels in blood

Mutation analysis

Sweat test - Cl >60= positive for CF

9
Q

What are the 2 cardinal features of cystic fibrosis?

A

Pancreatic insufficiency - abnormal stools, failure to thrive

Recurrent bronchopulmonary infections

10
Q

How do you treat pancreatic insufficiency in CF?

A
Enteric coated enzyme pellets
High energy diet - lots of fats
Fat soluble vitamins and minerals
H2 antagonist inhibitors
Proton pump inhibitors
11
Q

What are some complications of recurrent bronchopulmonary infections?

A
Pneumonitis
Bronchiectasis
Haemoptysis
Scarring
Abscesses
Respiratory failure
12
Q

How do you prevent infections in CF?

A
Segregation
Airway clearance and adjuncts
Mucolytics
Prophylactic antibodies e.g. Staph Aureus
Annual influenza jabs
13
Q

How do you treat chronic infections in CF?

A

Continue Abx
Try and reduce bacterial load
Treat exacerbations
Reduce inflammation - ibuprofen, prednisalone and azithromycin

14
Q

What is the predicted average life span of CF patients in the 21st century?

A

> 50yo

15
Q

What are some other manifestations of CF that can lead to its identification?

A
GI dysmotility
Hepatopathy
Upper airway polyps and sinusitis
Diabetes
Osteopenia
Heat exhaustion
Bilateral absence of vas deferent
Male infertility
Vaginal candidiasis and stress incontinence
16
Q

List some airway clearance techniques

A

Percussion and drainage
Autogenic drainage
Active cycle of breathing

17
Q

List some airway clearance adjuncts

A

Positive expiratory pressure mask
Cornet/flutter
High frequency chest wall oscillation

18
Q

List some mucolytics

A

DNase alfadornase

Hypertonic saline

19
Q

How does undiagnosed CF in adults usually present?

A
Recurrent pulmonary infections
Pancreatic insufficiency 
GI problems
DM
Liver disease
Osteoporosis
Infertility
20
Q

What do abnormalities in CFTR lead to?

A

Decreased mucociliary clearance, increased bacterial adherence and decreased endocytosis of bacteria = infections

21
Q

List some important infectious agents in CF

A

Pseudomonas aeruginosa
Burkholderia cepacia
Stenotrophomonas maltophilia
Mycobacterium abscessus

22
Q

Describe Pseudomonas aeruginosa infections in CF

A
Colonisation increases with age
Forms a protective biofilm
Rapidly acquired multi drug resistance
Reduces life expectancy by 10 years
Rapid decline in lung function
23
Q

Why does colonisation of Pseudomonas aeruginosa increase with age?

A

Repeat antibiotic use
Environment
Exposure from other CF patients

24
Q

How do you treat Pseudomonas aeruginosa infections?

A

Oral ciplofloxacin and nebulised colomycin

If fails:

IV Ceftazidine and nebulised colomycin

25
Q

Describe Burkholderia cepacia infections and CF

A

Organism acquired from environment and other CF patients
Associated with reduced life expectancy of 20 years, rapid decline in lung function and some patients develop CEPACIA syndrome, causing rapid deterioration
Innate resistance to most antibiotics

26
Q

What is Burkholderia cepacia Genomovar III a contraindication of?

A

Transplantation

27
Q

Describe Stenotrophomonas maltophilia infection in CF

A

Increasing frequency of colonisations
Usually after Pseudomonas
MDR, unsure of effect on prognosis

28
Q

Describe Mycobacterium abscessus infection in CF

A

Rapid increase in infections
Due to increased use of azithromycin?
Resistant to all anti-TB drugs
CI for transplantations due to abscesses

29
Q

Which infections require oral antibiotics?

A

Staph
Haemophilus
Pneumococcus

30
Q

Which infections require IV antibiotics?

A

Pseudomonas
Stenotrophomonas
Burkholderia

31
Q

What antibiotic types are used?

A

beta lactam and aminoglycosides

32
Q

What is Ivacaftor?

A

CFTR potentiator for G551D patients, improves the transport of Cl ions

33
Q

When are CF patients indicated for lung transplantation?

A
Rapidly deteriorating lung function
FEV1 <30% predicted
Life threatening exacerbation
Estimated survival <2 years
Severe weight loss
Hypoxia at rest
Desaturations at night
Hypercapnia
Recurrent worsening sepsis
Worsening QOL
34
Q

What two infection types are contraindications for lung transplantation?

A
Burkholderia cepacia (Genemovor III)
Mycobacterium abscessus
35
Q

Describe fertility issues in CF patients

A

No effect on sexual function
Puberty may occur up to 2 years later
Fertility affected in men (blocked/absent vas deferens)
Females fertile but poor nutrition may affect conception

36
Q

What is the outer shell of an ovum called?

A

Zona pellucida

37
Q

What are some options available for men with fertility issues trying to conceive?

A

Adoption
Artificial insemination with donor sperm
Intra-cytoplasmic sperm injection

38
Q

What are the possible outcomes of assessment for transplantation?

A
Active list
Passive list
Too well
Decision not to go on list
Too unwell
39
Q

List some absolute contraindications for lung transplantation

A
Other organ failure
Malignancy within 5 years
Significant peripheral vascular disease
Drug/nicotine/alcohol dependance (6m off)
Active systemic infection
Mycobacterial abscessus infections
Burkholderia Cepacia Genomovor III
40
Q

List some relative contraindications for lung transplantation

A
Organ dysfunction
Non-compliance of treatment
Steroids >20mg daily LT
Absence of recognised social support
Osteoporosis
Low BMI (18+)
Surgical risks e.g. previous thoracic surgery