Nutrition Interventions for Children with Special Health Care Needs

Chapter 17
Section 3 - Condition-Specific Nutrition Interventions
Nutrition Interventions for Cystic
Fibrosis
Susan Casey, RD, CD
Cystic fibrosis (CF) is a complex, multi-system disorder characterized by abnormally
thick secretions from the exocrine glands that impair the function of the lungs and
digestive system. It is one of the most common genetic disorders in children. The
incidence is highest among Caucasians, approximately one in 3200 persons in the
Caucasian population (1).
The median age of survival for persons with CF today is greater than 31 years, quite
an improvement over 1950 when the average life expectancy was one year. The
primary cause of morbidity and death in patients with CF is progressive pulmonary
disease (2).
The major clinical manifestations of CF include chronic lung disease; increased
levels of sodium, potassium, and chloride in the sweat; and exocrine pancreatic
insufficiency, which is a reduced or absent production of digestive enzymes and a
reduced secretion of bicarbonate. The child with untreated CF may have growth
failure, malnutrition, chronic pulmonary symptoms, bulky, foul-smelling stools, and
abdominal cramps. Typical pulmonary symptoms are chronic cough, asthma-like
symptoms, recurrent pneumonia, nasal polyps, and chronic sinusitis (3).
The diagnosis of CF is confirmed by two positive sweat chloride tests (Gibson-Cook
method), properly performed and interpreted. Every person with CF should have this
diagnosis confirmed in a facility that is approved by the Cystic Fibrosis Foundation.
The approved Cystic Fibrosis Centers are required to maintain the highest diagnostic
and treatment standards. Since the gene responsible for cystic fibrosis was identified
in 1989, genotyping with two identifiable alleles has also met the requirement
for diagnosis in the presence of an ambiguous sweat chloride test or a quantitynot-sufficient
sweat chloride test (4). Two positive genotypes for CF can also be
considered diagnostic.
CF Newborn Screening is available in all states. In Washington, all infants are tested
for IRT (Immunoreactive Trypsinogen) at birth. Infants with two positive IRT’s are
Nutrition Interventions for Children With Special Health Care Needs 191