cystic fibrosis Flashcards
1
Q
ethnicity and CF
A
more common in European descent
2
Q
What is CF?
A
- autosomal recessive genetic disorder
- mutation in a single gene on the long arm of chr 7
- most common mutation is the delta F508 (deletion, pehenylalanine at position 508)
- high salt concs in sweat (‘sweat test’)
- thick and sticky mucous becayse of lack of water
3
Q
CFTR (mutation)
A
cyctic fibrosis transmembrane conductance regulator
4
Q
diagnosis of CF
A
- newborn screening with ‘heel prick’ test - measure immunoreactive trypsinogen levels in blood
- genetic mutation analysis
- sweat test - measures the conc of chloride excreted in sweat (inc in CF)
5
Q
problems CF causes in the body
A
- excessive salt loss in sweat
- OP
- growth retardation
- respiratory failure
- GI disorders
- infertility
6
Q
pulmonary effects of CF
A
- impaired mucociliary clearance
- airways clogged with thick sticky mucous
- impairs clearance of microorganisms
- early colonisation of lungs with Staphylococci or H influenzae
- infections cause large inflam response
- act of neutrophils
- acc of debris from bacteria and neutrophils difficult to clear
- proteases of neutrophils damage airways
- cycle of infection & inflamm continues, lung fxn compromised
7
Q
airway infections
A
- close monitoring of secretions (cough, swab, sputum culture)
- reg mon of lung fxn with spirometry, O2 sats
- without ABX can deteriorate quickly, fatal respiratory failire
- Tx threshold diff to no CF person
8
Q
staphylococcus aureus
A
- usually initial infecting pathogen
- continuous prophylaxis as child
- minor exacerbations - oral flucloxacillin
- severe exacerbation - IV flucloxacillin or vancomycin
9
Q
MRSA
A
- pt/family swabbed
- if in nasal - Tx with Mupirocin
- MRSA causing Sx - fusicid acid + rifampicin/trimethoprim, oral linezolid
- severe/acute exac - IV teicoplanin/vancomycin
10
Q
haemophilus influenzae Tx
A
- oral amoxicillin
(if sensitive and no recent Hx of s/ aureus) - severe infections - chloramphenicol, cefuroxine (cephalosporin, tendonitis, seizure)
11
Q
pseudomonas aeruginosa
A
- recurrent infections eventually lead to chronic colonisation
- chronic colonisation causes rapid decline in lung fxn
- pts have a 2-3 fold inc risk of death over 8yr period
12
Q
exacerbations of P. aeruginosa
A
- treat early infections aggressively (attempt eradication)
- eradication regimens
13
Q
eradication regimens for P aeruginosa
A
- 6 weeks ciprofloxacin and 3-6mth colistin
- 3 mths ciprofloxacin and colistin
- inhaled tobramycin (intol to ciprofloxacin and colitin or early regrowth of P aeruginosa or other Tx failed)
severe exacerbation, broad spec agets:
1. IV Tazocin
2. IV aminoglycosides (comb synergistic effect with beta latams)
14
Q
caution with IV aminoglycosides (gentamycin, tobramycin)
A
nephrotoxicity
ototoxicity
15
Q
nebulised antibiotics
A
- solution of drug into a fine spray
- inhaled, delivering the ABX deep into the lungs
- P. aeruginosa, reduce rate of lung deterioration and the number of IV courses needed
- colistin and tobramycin have been used
