Wheeze and CF

Question 1

Transient early wheeze info:

Answer 1

• Transient early wheeze - small airways being more likely to narrow and obstruct due to inflammation and abnormal immune responses to viral infection.
• Episodic nature - triggered by viruses causing common cold.
• These children usually have decreased lung function from birth due to small airway diameter.
  RF: Maternal smoking during/after pregnancy, prematurity, more common in males.
  FH of asthma and allergy ARE NOT risk factors.
  This usually resolves by 5 years due to increase in airway size.

Question 2

Viral induced wheeze info:

Answer 2

• Wheeze is extremely common in pre-school children, 25% have episode of wheeze before 18 months.
• Many children with cough and wheeze DO NOT FIT into pneumonia or bronchiolitis category, but are too young (<5 yrs) to be diagnosed with asthma.

Question 3

Epidemiology and pathophys of viral induced wheeze?

Answer 3

• Most common diagnosis made on paediatric wards.
• RSV - most common
• Bronchial hyper-reactivity caused by infection.

Question 4

Clinical presentation of viral induced wheeze?

Answer 4

1) Wheeze preceded/concurrent with coryza symptoms (URTI).
2) NO INTERVAL SYMPTOMS (UNLIKE ASTHMA) e.g. no exercise induced wheeze or nocturnal cough when virus has cleared or triggers by allergens.
3) NO ATOPY (Ddx with Asthma)

Question 5

Ddx for viral induced wheeze?

Answer 5

1) Cystic Fibrosis
2) Bronchiolitis/Tracheo-bronchomalacia
3) Transient early wheeze
4) Asthma
5) Ciliary dyskinesia - build up of secretions and inflammation
6) GORD

Question 6

Diagnosis of viral induced wheeze?

Answer 6

1) Clinical presentation

2) Nasal secretion swabs - Viral PCR to identify RSV

Question 7

Treatment of viral induced wheeze?

Answer 7

1) Likely to improve with age
2) Inhaled Beta-2 agonist via spacer - Salbutamol given for 8 weeks in the lowest effective dose
3) Oral steroids e.g. Prednisolone - only helpful if SEVERE
4) Assess benefit by reduction in sleep disturbance
Inhaled ICS probably better for atopic individuals in asthma.

Question 8

Epidemiology of CF? and Risk factors?

Answer 8

• Autosomal recessive condition - 25% condition, 50% carrier.
• Most common in caucasians, less common in blacks and browns.
• Multi-system disease but respiratory problems are the most prominent. Most have pancreatic insufficiency.
• Life expectancy for current newborns is into the 40s.

RF: Caucasian and FH

Question 9

Pathophys of CF?

Answer 9

• Multisystem disorder relating to the abnormal ion transport across epithelial cells.
• CF gene on long arm of chromosome 7 coding for CFTR protein.
• CFTR protein is a transporter on the membrane for epithelial cells - exports negative ions such as chloride (and Na+ follows passively) causing an osmotic gradient where water moves out of the cell into the mucus.
• Mutation in CF gene results in defective CFTR - defective CL- secretion therefore increased Na+ and H20 absorption into cells - thickened secretions in a number of organs.
• Dysregulation of inflammation and defence in lungs.
• In intestines - thick viscous meconium is produced leading to meconium ileum in 10-20% of infants.
• Pancreatic ducts become blocked by thick secretions leading to pancreatic insufficiency and malabsorption.
• In Lungs: CFTR dysfunction - dehydrated airway surface liquid, mucus stasis, airway inflammation, and recurrent infection. This predisposed lung to chronic pulmonary infections - Pseudomonas Aeruginosa.
• Originates in small airways - progressive airway obstruction and bronchiectasis.

Question 10

Presentation of CF overview?

Answer 10

• Multisystem but majority of cases eventual cause of death is respiratory. Lungs of babies with CF are normal at birth - frequent respiratory infections soon develop and are presenting feature.
• Inflammatory response damages airways and results in progressive bronchiectasis, airflow limitation and eventual respiratory failure.

Neonates - Failure to thrive, meconium ileus (bowel obstruction due to thick meconium), rectal prolapse.

Question 11

CF respiratory symptoms?

Answer 11

Respiratory:

1) Persistant productive cough
2) Thick mucus
3) Wheeze
4) Recurrent infections
5) Bronchiectasis and airflow limitation
6) Pneumothorax and haemoptysis
7) Hyperinflated chest due to air trapping
8) Coarse inspiratory crepitations and/or expiratory wheeze.

Question 12

CF Alimentary symptoms?

Answer 12

Alimentary:

1) Reduced pancreatic enzymes (mucus blockage) - pancreatic insufficiency.
2) Diabetes mellitus and Steatorrhea (fatty stools due to malabsorption).
3) Distal intestinal obstruction syndrome (equivalent of meconium ileum) - reduced GI motility
4) Poor nutrition (maldigestion and absorption)
5) Cholesterol Gallstones and cirrhosis
6) Peptic users and malignancy

Question 13

CF other symptoms?

Answer 13

Other:

1) Male infertility - atrophy of vas deferent and epididymus
2) Females can conceive but secondary amenorrhea with progression of CF.
3) Salty sweat
4) Finger clubbing
5) Osteoporesis

Question 14

Diagnosis of CF?

Answer 14

1) Newborn Guthrie test - heel-prick bloodspot biochemical screen (check IRT levels - raised in CSF)
2) Clinical History
3) Family History of CF
4) 1 or more: Sweat test (showing high sodium and chloride), GI and nutritional disorder, absent epididymis and vas deferents (urogenital abnormality).
5) Genetic screening for known CF mutations
6) Faecal elastase test - low/no levels of elastase due to mucus blocking release from pancreas.
7) Microbiology: Pseudomonas aeruginosa, mycobacterium abscesses, enterobacterspp, Klebsiella, Prevotella spp.

Question 15

Treatment of CF?

Answer 15

1) MDT
2) Lung function (FEV1) and BMI
3) Education, nutrition and prompt treatment of exacerbations.
4) Prophylactic antibiotics - Flucloxacillin for Staph aureus, and Amoxicillin for H.influenzae.
5) Pseudomonal and flu vaccine
6) MRSA present - Rifampicin and Fucidin
7) Pseudomonas aeruginosa - Ciprofloxacillin, nebulisted colomycin
8) Regular chest physiology - remove secretions through postural drainage and forced expiratory techniques
9) SABA and inhaled ICS for symptom relief
10) Mucolytics - Dornase alfa (neb) and inhaled DNAse- clear airways of mucus
11) Pancreatic enzyme replacement therapy taken with all meals
12) Fat soluble vitamin supplements (ADEK)
13) Screening for osteoporosis and treatment
14) Amiloride - inhibits Na+ transport - mucus less thick
15) Bilateral lung transplant - maximal treatment and compliant, psychologically well, sick but not too sick FEV1 of 30%, HLA compliant, reasonable bone health.
M abscesses bacteria - NO TRANSPLANT, associated with a rapid decline and active infection may preclude transplantation.