Flashcards in Cystic fibrosis/bronchiectasis -Goya Deck (17):
What is Bronchiectasis?
Bronchiectasis is a irreversible dilation and destruction of one or more bronchi with inadequate clearance and pooling of mucus in the airways
Bronchiectasis is characterized by persistent microbial infection and/or inflammatory response
Bronchiectasis is often divided into disorders associated with cystic fibrosis or non-cystic fibrosis forms
What tests can be used to distinguish between cystic fibrosis and non-cystic fibrosis bronchiectasis?
Nasal transepithelial potential
What is the most frequent lethal genetic disease of white Americans?
median survival is not 36.8 years old and >20% are diagnosed after 15 yo
What is cystic fibrosis?
an autosomal recessive genetic disorder that affects the transmembrane conductance regulator (CFTR) gene
-chronic bacterial infection of the airways
-disrupts ion transport across epithelial membranes --> airways, sweat ducts, pancreatic ducts and intestine
What genetic defect is associated with cystic fibrosis?
**70% have the deletion of the F508 locus on chromosome 7
--> defect in chloride conductance causing an increase in Na+ reabsorption
What happens in the airway of a CF pt?
Cilia matted down in thick mucus and cannot rid airway of foreign particles.
Necrosis of neutrophils releases DNA and actin--> thick, tenacious mucus
get more bacterial infections and more tissue damage
recurrent bronchitis-> bronchiectasis--> chronic reap failure --> death
What is the diagnostic criteria for CF?
One or more clinical features of CF
Two CF mutations (used with borderline or normal sweat Cl- valves)
Two positive sweat chloride values (easiest) (>60 in children and > 80 in adults=CF)
An abnormal nasal transepithelial potential difference value
Who should a CF mutation screening be offered to?
Should be offered to adults with:
-a positive family history of CF
-partners of people with CF
-couples currently planning a pregnancy
-couples seeking prenatal testing
Why are organisms difficult to eradicate once established in the lungs of a CF pt?
Poor penetration of antibiotics into purulent secretions
Native or acquired antibiotic resistance
CF-related defects in mucosal defenses
Alginate produced by mucoid Pseudomonas aeruginosa (most common bug in adults), interferes with phagocytic killing
What are some of the signs and symptoms of CF?
Sputum production, Rhinitis with/without sinusitis, Hemoptysis, Wheezing, Dyspnea, Chest pain, digital clubbing, wheezing, nasal polyps, rales, chest deformity
GI: Pancreatic insufficiency, Abdominal distention, Intestinal obstruction, Heptosplenomegly, Cirrhosis
GU: Bilateral absence or atrophy of the epididymis, vas deferens & seminal vesicles, decreased semen volume & aspermia, infertility rate of 95-97% in males, decreased water content of cervical mucus --> infertility in women.
What x-ray findings are common with CF?
-Hyperinflation of CXR
-Increased bronchial markings
-Pneumothorax (late complication)
-Right heart & pulmonary hypertension
What is the best predictor of mortality in CF?
The FEV1 is the best predictor of mortality in CF
FEV1 >60% predicted, all alive for next 4 years
FEV1 <35% predicted, 40% will die in next 4 years
What are the 3 general principles of CF treatment?
Control of Infections: (oral antibiotics, IV antibiotics, inhaled antibiotics, vaccines)
-influenza and pneumococcal vaccine
Treatment of Inflammation:
-prednisone, azithromycin and ibuprofen (no inhaled corticosteroids!)
Treatment of Airway Obstruction:
-remove secretions (postural drainage/chest percussion, PEP valve, inhalation of 7% hypertonic saline, inhaled DNase
-exercise and breathing exercises to improve cough and increased peak flow rates
What did azithromycin (macrolide) therapy do in CF?
fewer exacerbations of CF lung disease
unknown mechanism of action
What is used for treatment of plumonary exacerbations in CF pts? maintenance?
IV antibiotics for exacerbations
inhaled for maintenance (colistin, aztrian)
How can nutrition affect CF?
malnutrition can worsen CF
CF pts need high calorie, high protein diet, vitamin A, D, E, and K supplements and often pancreatic enzyme supplements