Cystic Fibrosis Flashcards
KNOW What are the major pathogens in cystic fibrosis
KNOW the major pathogens are pseudomonas and staph
CF Etiology
Most common genetic disease in Canada
Treatable but not curable
Caucasians are most often affected
Most cases of cystic fibrosis will be confirmed before age 1
The median life expectancy is 31 years
But some people will live beyond 50 years of age
Death will usually be cause by pulmonary complications
CF and Genetics
Cystic fibrosis is a genetic disease that is caused by mutations in a pair of genes that are located on chromosome 7
Normally, every cell in the body has 46 chromosomes with 23 pairs (½ inherited from father and ½ inherited from mother)
More than 700 different cystic fibrosis mutations have been identified on chromosome 7
The most common mutation is ΔF508
These mutated genes will be responsible for the production of a protein known as cystic fibrosis transmembrane regulator (CFTR)
CFTR is the reason for thick secretions, which can clog ducts and glands
What does mutations to the function of CFTR do
- The absence, abnormal production, or function of the CFTR leads to abnormal electrolyte and water movement in and out of epithelial cells, including those lining the:
- Bronchial airways
- Intestines
- Pancreas
- Gall stones
- Liver ducts
- Sweat glands
- Vas deferens-Can affect fertility in both males and females, but primarily in males and uncommon to see in females
- The abnormality in CFTR results in thick mucus accumulates and blocks
- Bronchial airways
- Passageways of pancreas etc.
- This condition inhibits the digestion of protein and fat
- The inhibition of digestion leads to a deficiency of vitamins: — A, D, E, K
- Diarrhea, malnutrition, and weight loss also are common
- Meconium ileus develops in some infants
- Meconium ileus: bowel obstruction that often leads to perforation (meconium peritonitis)
If both parents carry the cystic fibrosis gene, what is the possibility of their child have CF
If both parents carry the cystic fibrosis gene, the possibility of their children having cystic fibrosis follows the standard Mendelian pattern
25 % chance of having disease if both parents are carriers of recessive gene (25% no disease, 50% carrier)
1 in 25 carry CF gene
Anatomical Alterations
- Excessive mucus production and accumulation of thick, tenacious mucus in the trachea-bronchial tree
Thick secretions are the hallmark of this disease
Partial or total bronchial obstruction (mucus plugging)
Atelectasis
Hyperinflation of alveoli
Gastro-Intestinal Complications of CF
- Failure to thrive
- Foul spelling greasy stool
- Voracious appetite
- Milk and formula intolerance
- Rectal prolapse
- Meconium ileua
- Meconium peritonitis
- Bowel Perforation
- Distal intestinal obstruction syndrome
- Pancreatic insufficiency
- Pancreatitis
HEPATOBILIARY
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
INFERTILITY
Will be in males only
Obstructive azoospermia
Diagnosis of CFT
There needs to be a labatory finding confirmed as well as a confirmed componenet of family history or clinical manifestation
Labartory Findings
There needs to be a confirmed labartory finding from below as well as a clinical manifestation
-
Sweet Chloride Level
- >60 mEq/L in children
- Sweat chloride most common
-
Two CFTR mutations
- Elevated levels of serum trypsinogen Abnormal difference in voltage potential reflects CFT
- Abnormal differences in voltage potential across the nasal epithelium
Cardiopulmonary Clinical Manifestations
- The clinical manifestations results from the pathophysiologic mechanisms caused/activated by
- Atelectasis
- Bronchospasm
- Excessive Bronchial Secretions
- The major anatomic alterations of the lungs associated with cystic fibrosis
- It is like patients have pneumonia all the time
- There are a lot of preventative measures in regards to infection and atelectasis
Clinical Bedside Data
- Increased RR, HR, CO, BP
- Use of accessory muscles of inspiration and expiration
- Pursed-lip breathing
- Increased anteroposterior chest diameter (barrel chest)
- Cyanosis
- Digital clubbing
- Peripheral edema and venous distention
- Distended neck veins
- Pitting edema
- Enlarged and tender liver
- Cough, sputum production, hemoptysis
Chest assessment findings
- Decreased or increased tactile and vocal fremitus
- Hyperresonant percussion note
- Diminished breath sounds
- Diminished heart sounds
- Crackles/rhonchi/wheezing
- Spontaneous pneumothorax
- Tactile and vocal fremitus
- Increased due to consolidation, secretions
- Decreased due to air trapping
Common Non-respiratory Clinical Manifestations
- Meconium ileus
- Meconium peritonitis
- Malnutrition and poor body development
- Deficiencies of vitamins A, D, E, and K
- Nasal polyps and sinusitis
- Infertility (males)
Sweat Chloride Test
Normal amount of sweat produced
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
~0.1 ml of sweat collected on absorbent gauze or filter paper (by squeezing it) and tested for chlorine concentration
Concentration > 60 mEq/L in children diagnostic of CF
Concentration > 80 mEq/L in adults diagnostic of CF
Blood Test
Complete blood count (CBC)
Elevated hemoglobin concentration and hematocrit
Increased white cells with superimposed infections
Radiologic Findings
Translucent (dark) lung fields
Depressed or flattened diaphragms
Right ventricular enlargement
Areas of atelectasis and fibrosis
Pneumothorax (spontaneous)
Abscess formation (occasionally)
Cor pulmonale
Air trapping
Constant infection
General Management
- Patient and family education
- PFTs
- Monitor FEV1
Respiratory Care Treatment Protocols
- Oxygen therapy protocol
- Home O2
- Bronchopulmonary hygiene therapy protocol
- Hyperinflation therapy protocol
- Aerosolized medication protocol
- Bronchodilators, mucolytics
- Mechanical ventilation protocol
- Mechanical vent only seen post-op, prep for transplant, end stage, or poorly
Treatment-Pharm to Mobilize Secretions
- Mucolytics, expectorants, aerosols, humidity to mobilize secretions
- Pulmozyme and amiloride
- Inhaled hypertonic saline also commonly used
- Used with small vol nebs
- Makes secretions less thick, easier to cough up
Treatment-Bronchoscopy
Either diagnostic or for bronch hygiene to suction
Treatment-Pharm
Bronchodilators, anti-inflammatory agents, xanthines
Antibotics
Oral quinolones, inhaled gentamicin or tobramycin
Treatment-Lifestyle
Diet changes-Pancreatic enzyme replacement, replacement of body salts, Vitamins A, D, K, E
Antibiotics
Treatment Mediated Gene Transfer
Mediated Gene transfer
Insert normal gene into cells of CF patient via virus
Reverse the electrolyte defect
RT are often involved
outpatients
Treatment- Transplants
Transplantation to increase life span
Liver and lung treansplants are commonly done
Bilateral lung transplants
Living lung transplant
Treatment-Chest Physical Therapy
- Postural drainage
- Cough assist techniques
- Airway oscillators
- A device which will transmit vibrations through the airways through intermittent positive expiratory pressure
- There are also MIE machines which provide and negative pressure to move secretions
- Important for these pts
- Help expectorate sputum
- Percussions and vibrations to get secretions moving
Prognosis of Cystic Fibrosis
Eventually overwhelmed by pulmonary secretions, infections and resulting patho-physiological changes in lung.
Require supplemental oxygen
Ventilation due to respiratory failure
Life expectancy 25 – 30 years
Lung transplant will increase life span 10 – 20 years
What is CF
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.
What causes the thick secretions in cystic fibrosis?
The disruption of the chloride transport causes the thick secretions in cystic fibrosis. Sodium is absorbed in the airways, pancreas, and bile ducts.
What would the x-ray look like for patients with cystic fibrosis?
Translucencies, enlarged heart, and a flattened diaphragm.
How is cystic fibrosis diagnosed?
Sweat chloride test is performed to screen for cystic fibrosis.
What two infections do we mainly see present in cystic fibrosis?
Staphylococcus Aureus and Pseudomonas.
. What common respiratory issues does a cystic fibrosis patient have?
Atelectasis, bronchial hyperreactive, asthma, hemoptysis, pneumothorax, pulmonary hypertension, respiratory failure, sleep breathing problems and symptomatic rhinosinusitis.
Aside from respiratory issues, what other clinical condition does a cystic fibrosis patient have?
Anemia, appendicitis and cystic fibrosis-related diabetes (CFRD) due to the scarring of the pancreas. Studies show that 75% of adult suffering from cystic fibrosis has a gallbladder disease, gastroesophageal reflux disease (GERD), malnutrition, growth failure, infertility, pancreatitis and meconium ileus.