Chapter 23: Cystic Fibrosis Flashcards
Cystic Fibrosis (CF)
inherited autosomal-recessive disorder that causes the production of thick mucus that blocks exocrine glands and affects several body systems, including respiratory, gastrointestinal, and reproductive systems
- most common cause of chronic respiratory disease in children
- accompanied by multiple, severe respiratory infections
- the increased mucus production in the airways causes obstruction and stasis of fluid, providing a rich habitat for bacterial growth
- the pancreatic ducts are often blocked by mucus, prohibiting the secretions of pancreatic enzymes necessary for the metabolism of food nutrients
- in later childhood, the reproductive system is affected b/c ovarian ducts and the vas deferens may be occluded, leading to infertility
- also an increased loss of sodium , causing salt depletion in children
- more common in Caucasians
How is CF Transmitted
transmitted as an autosomal-recessive trait, which means that a child can receive a defective gene from either parent
- when both parents carry the defective gene, there is a 75% chance that the child will inherit one CF gene from each parent and manifest the disease
- there is a 50% chance that the child will inherit one defective gene and one normal gene from each parent and become a carrier of the disease
- there is a 25% chance that the child will inherit only normal genes and be free of CF
Where is the CF gene found?
been found on chromosome 7, which encodes cystic fibrosis transmembrane conductor regulator protein (CFTR)
-CTFR normally regulates the chloride channel and facilitates at the cell surface; abnormal functions of CFTR cause a disruption of sodium ion transport across the exocrine and epithelial gland cells and make the cell walls impermeable to chloride ions; this causes an excess of sodium and chloride found in the sweat of children affected by CF
>the loss of sodium and water from the airways increases the viscosity of the mucus and disrupts the ciliary mechanism (hair-like process) that is intended to clear the airways, predisposing the child to recurrent respiratory infections
CF and the Transport Defect in the Pancreatic and Bile Ducts
with inadequate excretion of pancreatic enzymes for food breakdown, children experience varying levels of protein and fat absorption
- with reduced protein and fat absorption, there is weight loss and failure to thrive, requiring an affected child’s diet to be high in protein and calories
- fat is excreted in the stool, resulting in abnormal bowel patterns, including steatorrhea (presence of excess fat in feces), diarrhea, and abdominal pain
CF and Meconium
the mucus gland produces thin, free-flowing secretions, but in CF it produces thick mucus that accumulates and obstructs the different organs
- in newborns, thick secretions may plug the small intestine and lead to failure in passing meconium (the first feces of a newborn infant, which is greenish black, odorless, and tarry)
- in the GI system, thick secretions impair the digestive system and lead to malnutrition in childhood
Meconium Ileus
may be the initial presentation of CF in the neonate
- demonstrated by a meconium stool that is described as thick and sticky and present in 15% of newborns with CF
- may cause obstruction which requires surgical removal
Signs + Symptoms
-wide range
-the severity of symptoms varies from child to child; b/c CF is a multisystem disease (failure of two or more organ systems), the symptoms are presented according to the body system affected
>Gastrointestinal Tract:
-Meconium ileus, prolonged jaundice, steatorrhea, rectal prolapsed
>Respiratory Symptoms:
-cracks, wheezes, diminished breath sounds, dry productive cough, tachypnea, hypoxia, and cyanosis
>Integumentary Symptoms:
-salty-tasting tears and skin
>Secondary Consequences:
-dehydration, malnutrition, intestinal atresia, idiopathic pancreatitis, biliary cirrhosis, cholestasis, emphysema and atelectasis, prolonged hypoxia, hemoptysis, bacterial pneumonia, diabetes, anemia, failure to thrive, osteoporosis
>Common Characteristics:
-thin and underweight (less than or equal to 10th percentile for height and weight on a standardized growth chart), barrel chest, protuberant abdomen and distention, wasted buttocks, thin extremities, listless and lethargic, delayed development of secondary sex characteristics and infertility, occlusion of the vas deferens in males, occlusion of the ovarian ducts in females
Diagnosis
based on child’s signs and symptoms, including a positive history of the disease in the family, absence of pancreatic enzymes, increase in the electrolyte concentration of sweat, and chronic pulmonary involvement
-chest x-ray films show patchy atelectasis and obstructive emphysema
-a quantitative sweat chloride test is performed on sweat obtained by iontophoresis of pilocarpine; the results of sweat test are determined differently depending on the age of the child; a chloride concentration of greater than 60 mEq/L is diagnostic of CF
>(normal values of sweat chloride test is less than 40 mEq/L)
>a concentration between 30 to 59 mmol/L for infants less than 6 months = intermediate range
>from 40 to 59 mmol/L in older children = intermediate range
-pancreatic dysfunction is apparent
-test for direct documentation of enzyme secretion are invasive and are not routinely done in older children; these tests help to evaluate the progression of the disorder and provide direction for suitable treatment
Prevention
- no known prevention
- in families where there is a known case of CF, identification of carriers may assist the parents in family planning decisions
Promoting Respiratory Function
a multidisciplinary approach is taken
-physician, nurse, respiratory therapist, social worker, dietician, and psychologist are important in the management of CF
Nursing Care
- goal of treatment is to ensure respiratory function, enhance nutrition, promote growth and development, and encourage independence in an individual child and family
- potential for complications r/t respiratory infection and malnutrition can be reduced or prevented by instructing the parents on proper nutrition, medication compliance, good handwashing, and avoiding contact with persons with respiratory infections
Medical Care
-airway clearance and antibiotic use are the key treatment modalities for lung disease r/t CF
>medicated aerosol therapy, chest physiotherapy (percussion and postural drainage to loosen and remove lung secretions), and antibiotic therapy
>some children with CF may have a central venous access device for frequent antibiotic administration
-inhaled mucolytic agents, recombinant human DNAse (Pulmozyme), inhaled hypertonic saline, and
-medication for chronic Pseudomonas infections, which include inhaled tobramycin (TOBI) and oral azithromycin
>most have a complete loss of pancreatic function and inadequate digestion of fats and protein; therefore, an important aspect of management is to replace the pancreatic enzymes; enzyme replacement is administered with meals and snacks so the digestive enzymes are mixed with food in the duodenum; enzyme replacement should not exceed 2500 lipase units/kg per meal
Nutrition
well-balanced, high-protein, high-caloric diet
- pancreatic insufficiency results in malabsorption of fat-soluble vitamins (vitamins A, D, E, K)
- daily vitamin supplementation is recommended
Caring for the child with Cystic Fibrosis at home
- teach about nature of the disease and prepare them to manage day-to-day minor complaints
- assist family in arranging for the portable suction machine and about the proper suctioning technique at home
- instruct family to do the respiratory therapy before a meal b/c chest physiotherapy may induce vomiting “of the thick tenacious mucus”
- teach different techniques used for chest physiotherapy and postural drainage and coughing exercises based on their child’s age; child needs to be suctioned, followed by chest physiotherapy and inhalation to liquefy the thick secretions
- teach about preferred meal plans, high-caloric diet, and mixing pancreatic enzyme with meal
- instruct the family to monitor the child’s weight to ensure proper growth patterns
- teach how to administer medications properly
- inform family how to access community resources and how to contact their home health nurse
Nursing Diagnoses for CF
- ineffective airway clearance r/t thickened secretions
- ineffective breathing patterns r/t tracheobronchial obstructions
- altered nutrition: less than body requirement r/t inability to digest and/or loss of appetite
- altered growth and development r/t inadequate thickening of nutrients
- high risk for infection r/t impaired body defense system
- altered family processes r/t frequent hospitalization/prolonged sickness