Cystic Fibrosis Flashcards
What will normally cause death in CF patients
Pulmonary Complications
What is cystic fibrosis?
It is a hereditary disease characterized by lung congestion and infection along with malabsorption of nutrients by the pancreas. A multifaceted disease caused by genetically defective chloride ions in the apical surface of the epithelial lining resulting in impaired chloride-flow across membranes through the cystic fibrosis conductance regulator (CFTR) channel.
What happens in cystic fibrosis?
Mucus clogs the lungs leading to chronic respiratory infections and mucus obstructs the ducts of the pancreas preventing digestive enzymes from reaching the intestines.
What system is cystic fibrosis a dysfunction of?
The exocrine system.
Where is the mutation is seen in CF
Mutations on chromosome 7 that encodes a multifunctional protein called the CF transmembrane conductance regulator (CFTR).
How many chromosomes are in the
46 chromosome and 26 pairs
what is the most common mutation
ΔF508
Main Functions CFRT
One of the main functions CFRT is to serve as an apical chloride channel in airway, intestinal, and exocrine cells.
The movement of chloride ions and regulation of sodium ions is important to the proper regulation of the water content of secretions.
CFTR is the reason for thick secretions, which can clog ducts and glands
The dehydrated viscous secretions that result from the CFTR abnormality lead to organ dysfunction resulting in the clinical manifestations of the disease.
What results in the varying levels of CF dysfunction
There are over 1900 known CFTR mutations, which are grouped into six classes that result in varying levels of CFTR production and dysfunction.
The abnormality of CFRT result in thick mucus that can block what
Bronchial airways
Passage way of Pancreas (inhibits digestion of protein and fat, vitamin deficiency)
Meconium ileus
Can result in infants with CF
Meconium ileus: bowel obstruction that often leads to perforation (meconium peritonitis)
If both parents carry the recessive gene what is the chance of the baby having CF
25% as it is a recessive disorder
ANATOMICAL ALTERATIONS of CF
Excessive mucus production and accumulation of thick, tenacious mucus
Partial or total bronchial obstruction (mucus plugging)
Atelectasis
Hyperinflation of alveoli
GASTRO-INTESTINAL Symptons of CF
Foul spelling greasy stool
Meconium ileus in infants-Ability to expel meconium has been blocked
Bowel Perforation
Pancreatic insufficiency=Malabsorption of fats and proteins resulting in failure to thrive
Pancreatitis
HEPATOBILIARY in CF
- Hepatomegaly
- Focal Biliary Cirrhosis
- Prolonged Neonatal Jaundice
- Cholelithiasis (Gall Stones)
NUTRITIONAL DEFICITS
Fat-Soluble vitamin deficiency (vitamins A, D, E, K)
Hypoproteinemia
Hypochloremia
Metabolic acidosis
What leads to the chronic cough in patients with CF
• The decreased airway surface liquid secondary to CFTR dysfunction leads to impaired mucus clearance, resulting in inflammation and infection of the airways that causes a patient to have a chronic productive cough.
CF and Chronic Airway Infections
Chronic airway infections can occur early in life, most frequently with S. aureus, H. influenzae, or Pseudomonas aeruginosa.
The major pathogens is pseudomonas and staph which is associated with greater declines in lung function
Infection Cycle
- As the disease progresses, the cycle of inflammation, infection, and lung damage results in lung hyperinflation and bronchiectasis.
- Patients with end- stage CF lung disease have severe debility from respiratory failure and may develop pulmonary hypertension and cor pulmonale
CF PResentation
o SOBOE o Increased RR, HR, cardiac output, blood pressure o Use of inspiratory and expiratory accessory muscles o Pursed lip breathing o Increased anteroposterior chest diameter (barrel chest) o Cyanosis o Digital clubbing o Peripheral edema and venous distention Distended neck veins Pitting edema Enlarged and tender liver o Cough, sputum production, hemoptysis
CF Chest Findings
o Decreased or increased tactile and vocal fremitus
o Hyperresonant percussion note
o Diminished breath sounds
o Diminished heart sounds
o Crackles/rhonchi/wheezing
o Increased due to consolidation, secretions
o Decreased due to air trapping
CF Non-Respiratory Manifestations
Anorexia, weight loss
Increased risk for diabetes
Liver disease can result in prolonged obstructive jaundice in the newborn period.
Males with CF have obstructive azospermia as a result of congenital absence of the vas deferens.
DIAGNOSIS of CF
The diagnosis of cystic fibrosis is confirmed what at least one item from each of the following areas are established
Sweet Chloride Level
Two CFTR mutations-Elevated levels of serum trypsinogen Abnormal difference in voltage potential reflects CFT
Abnormal differences in voltage potential across the nasal epithelium
Infant Screening-Failure to gain weight, Bronchiectasis, Recurrent Pancreatitis
Sweat Chloride Test
- Sodium Chloride concentration in sweat are abnormally high in CF
- Glands microscopically normal but secrete up to four times normal amount NaCl
- Test used to measure electrolyte concentration of sweat
- Stimulation of sweat production over forearm by applying sweat stimulating solution and placing electrode on it to induce current
- A small amount of a colorless odorless sweat producing chemical is applied to the patient’s arm. An electrode is attached to the chemically prepared area, and a mild electric current is applied to stimulate sweat production.
Sweat Chloride Test in Infants 6 months or younger
o ≤29 mmol/L: Normal (CF very unlikely)
o 30 to 59 mmol/L: Intermediate (Possible CF)
o ≥60 mmol/L: Abnormal (CF Diagnosis)
Sweat Chloride Test >6 months
o ≤39 mmol/L: Normal (CF very unlikely)
o 40 to 59 mmol/L: Intermediate (Possible CF)
≥60 mmol/L: Abnormal (CF Diagnosis)
