Cystic Fibrosis

cystic fibrosis (CF)

- inherited autosomal recessive trait

-- child inherit the defective gene from both parents

-- risk is 1/4 (25%) if both parents carry the gene

-- CF transmembrane conductance regulator (CFTR) protein located on the long arm of chromosome 7

Pathophysiology of CF

increased viscosity of mucous gland secretion that causes mechanical obstruction

- thick mucoprotein accumulates in glands and ducts and obstructs small passages of bronchioles and pancreas forming concretions

- first manifestations is meconium ileus- small intestine is blocked with thick puttylike, tenacious, mucilaginous meconium

pulmonary complications

- present in almost all children

- symptoms r/t stagnation of mucous in airway which results in colonization of bacteria leading to destruction of lung tissue

pathophysiology of CF in pancreas

- blockage prevents pancreatic enzymes from reaching the duodenum resulted in impaired absorption of nutrients

-- results in bulky, frothy, stools with undigested fat (steatorrhea) foul smelling putrefied proteins (azotorrhea)

-- destruction of pancreas increases incidence of diabetes (CF-related diabetes CFRD)- most common complication

pathophysiology of sweat electrolytes

- elevation of sweat electrolytes

-- sodium and chloride in sweat and saliva

-- primarily abnormal chloride movemement

prolapse rectum

occurs infancy and childhood because of large bulky stools, malabsorption and increased and intra-abdominal pressure (secondary to paroxysmal cough)

pathophysiology of reproductive systems of female

- fertility inhibited by viscous cervical secretions

- blocks sperm

- once pregnant at risk for preterm labor and low infant birth weight

- favorable nutritional status and pulmonary function correlate with favorable pregnancy

pathophysiology of reproductive systems of male

- most are sterile- due to blockage of vas deferens

- results in decreased sperm production

CF newborn screening

- immunoreactive trypsinogen (IRT) analysis

-- performed on dried blood and may be followed by direct analysis of DNA for presence of Delta F508 mutation (can increase parental anxiety)

--- positive test does not diagnose or rule out CF but identifies risk

--- can be diagnosed in utero by detection of two CF mutations in fetus

pulmonary function testing

sensitive index of lung function

stool analysis

- requires 72 hour sample with accurate recording of food intake

- radiography with contrast enema for diagnosis of meconium ileus

sweat chloride test (pilocarpine iontophoresis)

- stimulates production of sweat using 3mA electric current, collecting sweat of filter paper and measuring sweat electrolytes

- requires 2 samples for reliability

- normal sweat chloride is less than 40mEg/L

- concentration greater than 60mEq/L seen in CF clients (6 months or older)

- 40-59 mEq/L is determinate (need to repeat in 1-2 months)

- chest x-ray shows patchy atelectasis and obstructive emphysema

goals of pulmonary problems

- prevent/minimize pulmonary complications

- prevent chronic pseudomonas infection

- ensure adequate nutrition for growth

- encourage appropriate physical activity

most common pathogens of CF

- psedomonas aeruginosa

- burkholderia cepacia

- S. aureus

- H. influenza

- Escherichia coli

- Klebsiella pneumonia

- fungal colonization with candida or aspergillus

airway clearance therapies (ACT)

- percussion and postural drainage

-- done X2 daily (morning/evening)

-- do not perform before or immediately after meal

- positive expiratory pressure (PEP)

- active cycle of breathing technique

-- forced exhale or huffing

- autogenic drainage

- oscillary PEP

-- child wears vest

- high frequency chest compression and excercise

bronchodilators

- given before percussion and postural drainage when evidence of reactive airway disease or wheezing

recombinant human deoxyribonuclease

- decreases the viscosity of mucous

- given daily via nebulization before or with percussion and drainage

nebulized hypertonic saline (7%)

- increases mucus clearance, but can cause bronchospasm and not recommended for clients with severe disease

aerosolized antibiotics (tobramycin, aztreonam, colistin)

- beneficial for client with frequent pulmonary exacerbations

- given 2-4 week cycles

IV antibiotics via PICC line

- minimize needle sticks

- allows for blood draws

- if no improvement hospitalization may be required for continued IV therapy

- less frequently seen because of need to reduce risk of resistant organisms

blood streaking of sputum

associated with increased pulmonary infection

hemoptysis

- potentially life-threatening event that requires immediate treatment

- bed rest, IV conjugated estrogens (premarin), vasopressin (pitressin), vitamin K, fresh frozen plasma (FFP), cauterization/embolization via bronchoscopy

- severe causes may require lung resection

nasal polyps

- develop in 2/3 of clients r/t chronic inflammation

- treated with inhaled corticosteroids, decongestants, and mucolytics

- surgical intervention if other treatments not successful

saline irrigations

remove thick nasal secretions to reduce chronic sinusitis

replace pancreatic enzymes

- administered with meals and snacks

- amount of enzymes depends on severity

- usually 1-5 capsules with meals (smaller amount with snacks)

- goal is to obtain normal growth and to decrease number of stools to 1 to 2 per day

- enteric beads should not be chewed or crushed

high protein, high calorie diet

- breastfed infants- continue as long as possible and supplement with high-calorie formula if needed

- formula-fed infants- cow milk is usually adequate

- uptake fat-soluble vitamins ADEK is decreased.

constipation

- caused by malabsorption and non-compliance with enzymes (or adequate dosage)

- miralax, stool softners or rectal administration of meglumine diatrizote

- reduce GERD by using histamine-receptor antagonist and gastic mobility drugs, dietary modification and placing in upright position after feeding/meals

management of endocrine problems

- management of Cystic fibrosis relater diabetes (CFRD)

-- insulin resistance and insulin deficiency

-- requires close monitor of blood glucose levels

--- check 3X daily

--- need oral glucose lowering agents or insulin

--- diet and exercise management needed

--- incidence increases with age

--- microvascular complications

---- retinopathy and nephropathy

Median age of CF survival is...

40 years

hospital care of patients with CF

- pulmonary infection, uncontrolled diabetes, and coexisting medical problems that can not be treated as outpatient

- educate, reinforce and frank negotiation may be required to receive cooperation with medication compliance

- provide support to client and family to assist with coping

-- encourage support groups

transition to adulthood

- male sterile (not important)

- female: increased respiratory issues during pregnancy

- children will be carriers of CF gene mutation

- encourage setting of life goals

- prepare for end-of-life decisions when appropriate

- allow space for anticipatory grieving