13. Cystic Fibrosis Flashcards
What is cystic fibrosis?
AR
Abnormal apical membrane chloride channel which prevents luminal transport of chloride
What are the causes of death in cystic fibrosis?
Respiratory failure
Sepsis
Bronchial haemorrhage
Where is the CFTR gene located?
Long arm of chromosome 7
How many classes of CF are there?
6
1-3 are severe, 4-6 more mild
What is the most common CF mutation in Ireland?
Delta F508
What class of mutation is delta F508?
2
How is CF diagnosed?
Clinical features/CF history in sibling/positive newborn screening
and
positive sweat test/positive nasal PD/2 identifiable CF mutations
How does CF present in infancy?
Failure to thrive
Intestinal obstruction
How does CF present in childhood?
Failure to reach growth milestones
Recurrent chest infections
Abdominal cramps/diarrhoea
What are the respiratory findings in CF?
Panbronchiectasis
Nasal polyps/sinusitis
What are the GI findings in CF?
Pancreatic insufficiency/CF related diabetes
Liver disease
Intestinal obstruction
What are the non-RT or GI symptoms of CF?
Renal disease
Congenital absence of vas deferens
Osteroporosis
What are the symptoms of an exacerbation of CF?
Cough with increase in volume, purulence and viscidity of sputum
Increased wheeze or haemoptysis
Nasal/sinus symptoms
Onset from a few days to a few weeks
Why does lack of pyrexia not rule out infection in CF?
Their body is so used to infection that it no longer produces the normal response
What are the most common infectious organisms in CF?
Pseudomonas Staph aureus and MRSA H. influenza B. cepacia Stenotrophomas maltophilia Atypical mycobacteria Aspergillus and candida
What complications are associated with b. cepacia?
Can cavitate through the chest wall after a transplant: significant contraindication to be colonised with it
What is the defining feature of a stenotrophomas maltophilia infection?
Brick red sputum
What complications are associated with CF?
Haemoptysis Pneumothorax ABPA Atelectasis Type 2 resp failure, pulmonary hypertension and CCF
Why do CF patients have low BMIs?
Require lots of calories to breathe
What are the signs of CF on inspection?
Low BMI and delayed puberty Clubbed and cyanosed Hyperinflated chest Portacath and/or PEG tube Hepatosplenomegaly
What are the signs of CF on auscultation?
Creps everywhere
Expiratory wheeze
What nebulised therapies are given in CF?
Anti-pseudomonal antibiotics
DNAse
7% saline helps to clear sputum
Bronchodilators as needed (salbutimol)
What bronchodilators should be given if a CF patient has asthma concurrently?
Salmeterol or symbicort
What anti-inflammatory is given in CF?
Azithromycin to reduce the frequency of exacerbations
What treatment is given for ABPA?
Daily oral prednisone or monthly IV methylprenisolone and oral itraconazole
What maintenance treatments are given to overcome malabsorption?
Pancreatic enzyme tablets: Creon
vitamin A, D, E, K: aquadek
Proton pump inhibitors
PEG feeds/nutritional supplements
What drug is used to prevent liver disease?
Ursofalk
What potentiator is given in a G551D mutation?
Ivacaftor
What corrects are given in a delta F508 mutation?
Orkambi and symkevi
Kaftrio
What is the function of potentiators?
Increase ion flow by helping chloride channel come up to membrane and open more
What is the function of correctors?
Help channel stay open longer
What methods of airway clearance are used in exacerbations?
PEP mask
Flutter valve
Acapella
biPAP
What should be monitored at every CF appointment?
FEV1
BMI
Sputum culture
What annual measurements should be taken in CF?
Oral glucose tolerance Liver ultrasound Vit levels DEXA CXR or recent high res CT IgE for aspergillus FBC, U&E, LFTs, ca/phos, protein, albumin
What are indications for lung transplant?
Low FEV1
>1 exacerbation in the last 3 months
24>BMI>17
Age <24
What score is used to evaluate if a CF patient is a candidate for lung transplant?
CF-ABLE
What scar is seen post lung transplant?
‘Clamshell’
What is bronchiectasis?
Localised, irreversible dilatation of part of the bronchial tree due to destruction of muscle and elastic tissue
What does sputum normally look like in bronchiectasis?
Clear, frothy, white
What is a typical history for a patient with bronchiectasis?
Productive cough
Recurrent lower RTI
Intermittent haemoptysis
Over a period of years
What complications are associated with bronchiectasis?
Respiratory failure
Massive haemoptysis
Amyloidosis
What signs are seen in bronchiectasis?
Clubbing
Coarse creps +- wheeze
What investigations should be done in bronchiectasis?
High res CT thorax IgG, IgA, IgE Mannin binding lectin a1AT levels Sputum culture and susceptibility Sweat testing and CF genotyping
What is the maintenance treatment for bronchiectasis?
Chest physio
Nebulised DNA and anti-pseudomonal antibiotics
Alternate day azithromycin
