Cystic Fibrosis Flashcards
(47 cards)
Transmission of Cystic Fibrosis?
autosomal recessive
most common life limiting genetic disorder in white population
life span ~41
Genetic abnormality in CF?
long arm of chromosome 7
88% delta F508
Mutations of CFTR (cystic fibrosis transmembrane conductance)
Class I: defective protein production
Class II: Defective protein processing (protein not properly folded)
Class III: defective regulation (gets to channel but doesn’t work well)
Class IV: defective conductance
Class V: reduced number of active CFTR
Pathophys of CF?
2 defective CFTR genes >
defective CFTR protein >
abn Cl permeability altered ionic transport >
decreased water content in airway surface liquid >
mucus obstruction >
inflammation and scarring >
progressive loss of lung func.
Classic features of CF?
chronic sinusitis, severe chronic bi infx of airways, pancreatic exocrine insufficiency, meconium illeus at birth , sweat chloride value usually 90-110, obstructive azoospermia
Approach to care for CF?
good nutrition
pancreatic enzymes and vitamin supplementation
airway clearance and anti-inflammatory therapies
antipseudomonal agents
Pulmonary tx for CF?
chest physiotherapy, abx, pancreatic enzyme sup., multivitamins, antiobstructives, anti-inflammatory, CFTR modulators, vaccinations, supplemental O2, BiPAP, lung transplant
What is the recommended sequence of clearance therapy for CF (pulmonary toilet) regimen?
~concurrently with percussion therapy
- Bronchodilator (Albuterol)
- Hypertonic Saline
- Dornase alfa (pulmozyme)
- Aerosolized abx ( Aztreonam) indicated based on severity of lung disease and sputum cultures
Dornase alfa MOA?
enzyme cleave EC DNA, results in decreased viscosity of mucus
- airway in the lungs is improved
- risk of bacterial infection may be decreased
$$$
Effect of hypertonic saline?
administered to hydrate mucus –> draws water from the airway to re-establish the aqueous surface layer that is deficient in CF
What is the hallmark of CF?
presence of abundant, purulent airway secretions composed primarily of highly polymerized DNA
ADE of dornase alpha?
fever, rash, pharyngitis, rhinitis, dyspepsia, conjunctivitis, laryngitis
Should CF pts be treated with abx chronically to control infection?
NO
but there is an exceptions if using for anti-inflammatory properties:
-Azithromycin, Nebulized tobramycin, nebulized aztreonam
Most common bacteria in respiratory secretions of CF pts?
s. aureus
How does Azithromycin target pseudomonas bacteria?
reduces the ability of pseudomonas to produce biofilms
Effect of nebulized tobramycin?
improves lung func.
reduces acute pulmonary exacerbations chronically infected w/ P. aeruginosa
Nebulized tobramycin MOA?
interferes w/ bacteria protein synthesis by binding to 30S and 50S ribosomal subunits, resulting in a defective bacterial cell membrane
How is nebulized tobramycin dosed?
BID for 28 days, then alternate with 28 days off tx
ADEs of inhaled tobramycin
sputum discoloration
rales, wheezing, voice alteration
cough, abnormal taste,
eosinophilia
tinnitus
Inhaled Aztreonam drug class? MOA?
Monobactam (beta lactam)- abx with antipseudomonal activity
inhibits bacterial cell wall synthesis
ADEs of inhaled aztreonam?
fever, cough, rash, abd pain, vomiting
Dosage of inhaled aztreonam?
Alternate 28 days on, 28 days off
often Tobramycin and Aztreonam are alternated to provide continuous coverage
Ibuprofen MOA
reversibly inhibits cyclooxygenase 1 and 2 (COX 1 and 2 enzymes)
Who is high dose ibuprofen recommended for?
pts under 18 y/o with FEV1 > 60%
Effects:
-less decline in pulmonary func.
- able to maintain weight and less hospital admission
- freq. blood draws for PK monitoring
