Chapter 22: Cystic Fibrosis Flashcards Preview

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Flashcards in Chapter 22: Cystic Fibrosis Deck (11)
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Etiology of Cystic Fibrosis

- autosomal reccessive disorder of exocrine glands

- most common genetic lung disease in the US

- classified as airflow or suppurative (pus-forming)

- hypersecretion of abnormal, thick mucus that obstructs exocrine glands and ducts

- median survival age is about 31 years


Pathogenisis of cystic fibrosis

- Dysfunction of CFTR gene

- Primarily affects the pancreas, intestinal tract, sweat glands, and lungs, and in males causes infertility

- high concentrations of sodium and chloride in sweat, salivary, and lacrimal secretions (results in salty skin)

- mucus producing glands in the GI tract enlarge

- bronchopulmonary system is also affected by the thick, tenacious mucus


Pathogenesis of Cysitic Fibrosis (dysfunction of CFTR gene)

- normally CFTR encodes a membrane chloride channel and is in sweat glands, lungs, and pancreas

- CFTR gene mutations result in alteration in chloride and water transport across epithelial cells


Pathogenesis of Cysitic Fibrosis (mucus producing glands in GI tract enlarge)

- generates excessive secretions

- thick eosinophillic mucuous secretions plug the glands and ducts of the GI tract, causing dilation and fibrosis

- leads to decreased production of pancreatic enzymes, causing increased fat and protein in stool


Pathogenesis of Cysitic Fibrosis (Bronchopulmonary system affected)

- failure of chloride channels to function

- decreased flow of ions and water results in viscid (thick) mucus

- causes airway obstruction, ateletasis (collapse of alveoli) and hyperinflation and also decreases cilliary action (bc mucus)

- Provides a medium for pulmonary infection (pseudomonas staph)


Clinical Manifestations of Cystic Fibrosis (lung related)

- history of cough in young adult or child

- thick, tenacious sputum

- recurretn pulmonary infections and bronchitis

- Dyspnea, tachypnea

- Sternal retractions

- Unequal Breath sounds

- moist basilar crackles and rhonchi

- Barrel chest hyperresonant to percussion

- DIgital clubbing (late)


Clinical manifestations of Cystic Fibrosis (other)

- pancreatic insufficiency

- cirrhosis of the liver

- diabetes mellitus

- gallstones

- nasal pollyps

- failure of development of the vas deferens in males

- Nutrional assesment includes depleted fat stores, Steatorrhea (fatty stools), anorexia, and decreased growth rate in children


Diagnosis of Cystic Fibrosis

- ABG (hypoxemia and hypercapnia (unable to breath enough to get rid of CO2))

- PFT ( Decreased VC, airflow, and TV; Increased airway resistance, functional residual capacity)

- Chest xray (patchy atelectasis, bronchiectasis, cystic lung fields)

- sputum culture and sensitivity

- 72 hr stool collection (fat absorption and secretion)

- Genetic testing (marker AF-508 confirms diagnosis)


Treatment of Cystic Fibrosis

- aggressive treatment of respiratory infections

- postural drainage and chest physiotherapy (chest percussion)

- Forced expiratory technique


Medicinal Treatment of Cystic FIbrosis

- Bronchodilators

- Recombinant human deoxyribonuclease 1 (dornase alfa): digest extracellular DNA present in the viscid sputum

- High dose antibiotics

- Influenza Vaccine


Nutritional Therapy for Cystic Fibrosis

- unrestricted fat consumption; 30% of caloric intake

- high protein

- vitamin supplements, esp A, K, D, & E

- Pancreatic Enzymes

- Intake of 150% of normal caloric intake

- May need enteral feedings or IV (through tube)

- may need heart or lung transplant