Cystic Fibrosis Flashcards
Cystic fibrosis =
Most common autosomal recessive disease among Caucasian Americans
Affects lungs and GI system
Defective gene and its protein product cause the body to produce unusually thick, sticky mucus that clogs the lungs and obstructs the pancreas and stops natural enzymes from helping the body break down and absorb food
Symptoms
Salty-tasting skin
Persistent cough at times with phlegm
Frequent lung infections
Wheezing or SOB
Poor growth/wt gain in spite of good appetite
Frequent greasy, bulky stools or difficulty with BMs
Survival
Overall trend is imrpoved
Female survival rate worse than male b/t 2-20yo
Dx
Sweat chloride concentration >60mEq/L
In presence of 1 or more typical features:
Chronic sinopulmonary dz
Pancreatic insufficiency
Salt loss syndromes
Obstructive azoospermia
Appropriate fam hx (sibling or 1st cousin)
Who should undergo sweat testing
Infants c positive newborn screening results
Infants, older children, and adults c symptoms suggestive of CF
Siblings of a pt c confirmed CF
Organs affected
Airways Lungs Pancreas Liver Small intestine Reproductive tract Skin
Clinical Manifestations
Bronchiolitis/asthma Pseudomonas aeruginosa colonization of the respiratory tract Staphylococcal pneumonia Nasal polyposis Chronic productive cough Sinusitis Digital clubbing As dz progresses, chronic bronchitis c or s bronchiloectasis develops and can be accompanies by acute exacerbations
Sino-Pulmonary dz
Endobronchial dz: cough, sputum production, air obstruction - evidence of obstruction on PFTs, CXR anomolies, digital clubbing
Sinus dz: nasal polyps, CT or XR findings of panopacifications of paranasal sinuses
Colonization of Airway
80% of CF pts eventually end up with Pseudomonas infection
Association b/t acquiring Pseudomonas and clinical decline
Schamroth Sign
normal angle b/t nail and nailbed lost (digital clubbing)
Nutritional deficit
Insufficient secretion of digestive enzymes such as lipase leads to malabsorption of fat (with steatorrhea) and protein
Malabsorption presented as FTT or fat soluble vitamin insuffeciency (fat soluble vitamins = A, D, E, K)
Intestinal abnormalities
Hepatobiliary dz
Pancreatic endocrine dysfxn
Intestinal abnormality
Meconium ileus
Distal intestinal obstruction syndrome (DIOS)
Rectal prolapse
Hepatobiliary disease
Focal biliary cirrhosis
Multilobular cirrhosis
Pancreatic endocrine dysfunction
Cystic fibrosis related diabetes
CF related DM
Screening
Initiating insulin tx
Screening
Oral glucose tolerance test (OGTT)
Every two years in patients 10-16 years
Any patient with random plasma glucose >180
Fasting>=200 mg/dl
initiate insulin treatment
Fasting 140-200 mg/dl
Home glucose monitoring; consider insulin
Fasting <140
Normal glucose tolerance
Infertility
Common
Men:
Abnormal embryologic development of the epididymal duct and vas deferens—may be incomplete or absent
Congenital bilateral absence of vas deferans in 97-98%
Women:
Lower fertility rate than non-CF women
Viscid mucoid cervical secretions of low volume in women with CF
Sweat Chloride Test
Primary test for dx of CF
Positive Sweat chloride: 60-165 meq/L
Borderine sweat chloride: 40-60 meq/L
Normal sweat chloride:
0-40
Sweat chloride test:
False Positives
False Negatives
False positives: Hypothyroidism Addison disease Ectodermal dysplasia Glycogen storage disease Edema Malnutrition Lab error (evaporation or contamination of sample)
False negatives: Edema Malnutrition Some CF mutations Sample diluted
Genetic Testing
Mutation analysis available
Testing varies
Prenatal Screening
Option of prenatal screening for CF is recommended
Sensitivity of prenatal screen in white population < or =78
Newborn Screening
Goal: dx early
Evidence that early dx leads to better nutritional outcome and chest radiographic scores
Tx
While the focus of this discussion is on pulmonary therapies, it must be kept in mind that management is often suboptimal unless the multisystem nature of the disease is considered. Sinus infection, nutritional status, glucose control, and psychosocial issues must all be assessed at regular intervals. This requires a multidisciplinary approach to care that, in the United States, is best provided at one of more than 130 CF Care Centers
Aerosolized Abx
Tobramycin
The most common airway pathogen in patients with CF is Pseudomonas aeruginosa.
For patients with CF, 6 years of age and older, who have moderate to severe lung disease and with P. aeruginosa persistently present in cultures of the airways, the Cystic Fibrosis Foundation strongly recommends the chronic use of inhaled tobramycin to improve lung function and reduce exacerbations.
Azithromycin
For patients with CF, 6 years of age and older, and with Pseudomonas aeruginosa persistently present in cultures of the airways, the Cystic Fibrosis Foundation recommends the chronic use of azithromycin to improve lung function and to reduce exacerbations
Tx
Pulmonary Toilet/Airway Clearance
Chest physiotherapy
Postural drainage and percussion
P.E.P valve, Acapella valve, Flutter valve
High frequency chest wall oscillation
Albuterol
Bronchodilation
Increase ciliary efficiency
Dornase alpha/recombinant DNase
Hypertonic Saline by nebulization
Tx
Chronic infection
Pulmonary Exacerbation
Inhaled antibiotics
Inhaled tobramycin in patients with pseudomonas
Sputum cultures
Treatment of pulmonary exacerbation
Pulmonary exacerbation—change in symptoms and signs from baseline (cough, sputum production, lung function, increased crackles on physical exam)
Requires hospitalization for antibiotics IV, as well as increased airway clearance
Dornase Alpha
Recombinant human DNase (dornase alfa) was developed to degrade the large amount of free DNA that accumulates within CF mucus, thereby improving the viscoelastic properties of airway secretions and promoting airway clearance.
Hypertonic Saline Inhalation
increase hydration of airway surface liquid in patients with CF, thereby improving mucociliary clearance
Anti-Inflammatory Agents
Regular Ibuprofen use recommended
showed slower decrease in FEV1 and better weight maintenance
Best effect in pt’s <13yo
Cromolyn
Evidence insuficient to recommend for or against cromolyn use in CF
Corticosteroids
Evidence is insufficient to recommend for or against use of PO corticosteroids
Recommended against routine use of inhaled corticosteroids
Psychosocial Issues
QOL affected by: Frequent hospitalizations Time spent on therapies Morbidity from disease Restrictions secondary to disease
Discuss c pt:
Adherence to therapies
Family planning
Endo of life issues
