Cystic Fibrosis

Question 1

What is Cystic Fibrosis?

Answer 1

• Cystic Fibrosis is an autosomal recessive disease caused by a mutation in the CFTR gene

Question 2

Which systems are affected in Cystic Fibrosis?

Answer 2

• Respiratory System
• Pancreas
• Gastrointestinal Tract
• Reproductive Tract

Question 3

How is the Respiratory Tract affected in Cystic Fibrosis?

Answer 3

Respiratory Tract:
- The CFTR gene encodes the CFTR protein, which is a chloride channel present in epithelial tissues, chloride is driven against the concentration gradient using ATP
- CFTR is present on airway epithelial cells and submucosal glands
- When defective this results in disruption to chloride ion movement and affects sodium reabsorption hence decreasing the amount of water secretions. Resulting in reduced airway surface liquid.
- This in turn impedes mucus clearance
- The altered lung environment provides an area for bacterial growth

Question 4

How is the Pancreas affected in Cystic Fibrosis?

Answer 4

Pancreas:
- The pancreatic duct is typically occluded in utero causing permanent damage to the exocrine pancreas leading to patients with CF pancreatic insufficient

Question 5

How is the Gastrointestinal Tract affected in Cystic Fibrosis?

Answer 5

• The small intestine secretes viscous mucous which can cause a bowel obstruction = meconium ileus
• CF can cause cholestasis which results in neonatal jaundice
• Later in life Distal Intestinal Obstruction Syndrome can occur

Question 6

How is the Reproductive Tract affected in Cystic Fibrosis?

Answer 6

• 98% of men with CF are infertile due to the congenital absence of the vas deferens. It is suggested that the timing of pregnancy is carefully planned

Question 7

What are the Risk Factors for Cystic Fibrosis?

Answer 7

• Autosomal Recessive Condition

Question 8

What are the Clinical Features of Cystic Fibrosis in Neonates?

Answer 8

• Neonates: 1.Meconium ileus (abdominal distention, bilious vomiting and delayed passage of meconium), 2.Guthrie Test: introduction of screening in CF, 3.Failure to thrive, 4. Polonged Neonatal Jaundice

Question 9

What are the Clinical Features of Cystic Fibrosis in Infancy?

Answer 9

1. Failure to thrive
2. Recurrent Chest infections
3. Pancreatic insufficiency: steatorrhoea

Question 10

What are the clinical features of Cystic Fibrosis in Childhood?

Answer 10

• 1.Rectal Prolapse
• 2.Nasal Polyps
• 3.Sinusitis

Question 11

What are the clinical features of Cystic Fibrosis in Adolescence?

Answer 11

1. Pancreatic Insufficiency: Diabetes Mellitus
2. Chronic lung disease
3. DIOS, gallstones, liver cirrhosis

Question 12

What Investigations should you do for Cystic Fibrosis?

Answer 12

• Chloride Sweat Test
• Chest Radiograph: Hyperinflation, there may be evidence of bronchial thickening
• Microbiological Assessment - cough swab/sputum sample
• Lung function testing - Spirometry
  -Faecal Elastase - assess pancreatic function
• Chest CT - assess for bronchiectasis
• Genetic Analysis - assess for the mutations

Question 13

What is the Chloride Sweat Test?

Answer 13

• This test measures the electrolyte concentration in sweat
• sample is collected by Pilocarpine Iontophoresis
• Sweat Chloride >60mmol/L is suggestive of CF
• Sweat Chloride of 40-60mmol/L is borderline and should be repeated
• A single sweat test is not sufficient to diagnose CF, a second test/ identification of genetic mutation should confirm the diagnosis

Question 14

What is the management for Cystic Fibrosis?

Answer 14

• Patient and Family Education (clearly explain the diagnosis and provides written info and support)
• Airway Clearance and Chest Symptoms Management
• Nourishment and Exercise
• Managing/ Preventing Airway Infections
  -Other

Question 15

What is Included in Airway Clearance and Chest Symptoms Managment for the management of Cystic Fibrosis?

Answer 15

-Twice-daily Physiotherapy - increase the airway secretion clearance which should reduce airway obstruction and minimise risk of infection
-Mucolytics and DNase: DNase is inhaled and digests DNA which is found in the sputum of the patients this reduces the viscosity of the mucus.
Hypertonic Saline: can be used to aid airway clearance

Question 16

What is Included in Nourishment and Exercise in the management for Cystic Fibrosis?

Answer 16

• Encourage physical exercise
• Pancreatic enzyme supplementation (with meals which contain fats)
  -Vit A, D, E and K supplements
• Monitor Growth
• Children may have poor weight gain (Build-up milkshakes can be used to supplement meals // in extreme cases may be necessary to have supplemental enteral feeding)

Question 17

What is included in Managing/ Preventing Airway Infections in Cystic Fibrosis?

Answer 17

• COMMON AIRWAY INFECTIONS: Staphylococcus Aureus, Haemophilus Influenzae and Pseudomonas Aeruginosa
• Sputum Culture/ Cough Swab
• Infections should be treated with 2 weeks of Antibiotics at high doses
• PSEUDOMONAS AERUGINOSA Infection: Associated with poorer lung function and so it’s important to detect and aggressively treat this infection. Chronic infection results in colonies of Pseudomonas forming “biofilms” which protect them from host and antimicrobial attack.
• IV Abx may be needed to treat infections not responsive to oral Abx
• Prophylactic Abx are recommended in infants until the age of 3 years
• Regular Azithromycin has been shown to reduce exacerbations and improve lung function
• INFECTION CONTROL: Active segregation reduces cross- infection, each patient should be in a side room, each patient will have their own clinic room which is cleaned and undergoes adequate air exchanges prior to the next patient, patients are separated via Pseudomonas naive patients compared to chronic infection and those with non-tuberculous mycobacteria (NTM) they all attend a separate clinic

Question 18

What is Included in Other for the management of Cystic Fibrosis?

Answer 18

• Minimising Complications
• Monitoring the Disease (Annual Review): seen by resp paediatrician, dietician, physiotherapist and CF specialist nurse - review of clinical symptoms, Abx, microbiological assessment, bloods (FBC, Renal function, LFTs, Vit A,D,E,K, HbA1c)
• Chest X-Ray
• Oral Glucose Tolerance Test (OGTT- CF related diabetes)

Question 19

What are the Complications of CF?

Answer 19

• Respiratory
• Gastrointestinal
• Endocrine
• Arthritis
• Infertility

Question 20

What are the Respiratory Complications of CF?

Answer 20

• Allergic Bronchopulmonary Aspergillosis (ABPA) - immune response to the Prescence of Aspergillus spp. ABPA can be treated with oral corticosteroids and itraconazole
• Bronchiectasis
• Haemoptysis
• Pneumothorax
• Nasal Polyps
• Resp Failure, Pulmonary Hypertension

Question 21

What are the GI tract Complications in CF?

Answer 21

• Rectal Prolapse: frequent bulky stools, ensure the child has adequate pancreatic enzyme replacement and laxatives to minimise strains
• DIOS ( Distal Intestinal Obstruction Syndrome) - obstruction of the distal ileum seen with colicky abdominal pain and a palpable mass in the RLQ
• Cholestasis, Gallstones, Liver Cirrhosis

Question 22

What are the Endocrine Complications of CF?

Answer 22

• CF related diabetes (associated with rapid decline in lung function and disease progression, ensure the children are screened for DM, Retinopathy, hypertension and microalbuminuria screening at annual review)
• Delayed Puberty - average delay of 2 years, which can cause reduced bone mineral density which predisposes children to fractures later in adulthood