Nursing powerpoint

1. Phenylketonuria
By: Alex Epperson

2. Phenylketonuria - Alex
● Affects central nervous system
● “Genetic disease inherited as an autosomal
recessive trait caused by the absence of the
enzyme phenylalanine hydroxylase needed to
metabolize the essential amino acid phenylalanine”
(Hockenberry, 2019, p. 63).

3. Pathophysiology - Alex
● The hepatic enzyme phenylalanine hydroxylase is absent
● “This results in the accumulation of phenylalanine in the
bloodstream and urinary excretion of abnormal amounts of its
metabolites” (Hockenberry, 2019, p. 63).
● Phenylpyruvic acid makes the odor of the urine
● Tyrosine, one of the amino acids in phenylalanine forms melanin is
absent
(Hockenberry, 2019).

4. Clinical Presentation/Assessment
● Failure to thrive
● Hyperphenylalaninemia >360 mmol/L
● Frequent vomiting
● Irritability
● Erratic behavior
● Disorientation
● Seizures
● Abnormal electroencephalographs
● Schizoid behavior
● Urine odor/Breath odor
● Eczema
● Abnormally small head
● Fair skin and blue eyes

5. Diagnostics
●Phenylketonuria (PKU) is a condition included in mandatory newborn screening in all 50 states.
●24 hours after birth, the newborn is given the Guthrie bacterial inhibition assay, which screens for
phenylalanine in the blood.
●The test is administered by performing a heel stick and applying drops of blood to specialized test
paper which is sent to the lab for analysis.
●The normal range of phenylalanine in newborns in 0.5 – 1 mg/dl.
●A lab result of serum phenylalanine greater than 4 mg/dl is indicative of PKU and prompts a referral to
a genetic metabolic specialist.
●Additional blood, urine, and genetic tests are required to confirm diagnosis (Mayo Clinic, 2018).
●Some states require a second test to be performed at 1-2 weeks of age to ensure all PKU patients are
diagnosed, and treatment can begin promptly (Hockenberry et al., 2019).

6. Current Treatment and Disease Management
Treatment is managed by an interdisciplinary team consisting of a genetic metabolic specialist,
primary care physician, registered dietician, and pharmacist.
1. A lifelong diet which restricts protein is required for PKU patients.
○Avoid high protein foods: milk, eggs, cheese, nuts, soybeans, beans, chicken, beef, pork, fish
○Consult with pharmacist regarding OTC medications as many are made with aspartame (contains phenylalanine).
2. A PKU formula may be prescribed as a nutritional supplement to offer essential proteins but
exclude phenylalanine.
3. Lifelong follow up and lab work to track development and changes over time (Mayo Clinic,
2018).

7. Complications of the Disease – Emma
●When let untreated it can lead to complications
○Irreversible brain damage and intellectual disability in first few months of life
○Neuro problems (seizures and tremors)
○In older children and adults behavioral, emotional (unstable moods) and social
problems can occur
○When mothers with PKU have high phenylalanine levels during pregnancy
there is a risk for birth defect or miscarriage
(Hockenberry, 2019).

8. Nursing Indications/Interventions
●Restrict dietary protein
●Treatment in infants with levels between 120-360 umol/L
●Restricted phenylalanine dietà medical foods and low protein products
■ Milk substitutes with nutrients but no protein
■Diet begins no later than 3 weeks of age
●Diet is lifelong!
●Patient and Family teaching very important for good prognosis

9. Parent/Child Teaching
●Nutrition: foods with low phenylalanine levels (measured)
○Vegetables, fruits, juices, breads, starches
○Restrict/Eliminate: high-protein (meat and dairy)
●Problems start arising as child gets older
■Decreased appetite, picky appetite resulting in inconsistent phenylallanine levels
■Peer pressure influence
■Limited food with low levels
●Registered Dietitian is essential
●Support groups available for both the individual and their family

10. Exam Question- Emma
A new mother has some questions about Phenylketonuria (PKU). Which of the following is false
regarding PKU:
1.If a mother has PKU they have a risk for their baby to have a birth defect
2.If Mother has PKU they have a higher chance for miscarriage
3.Someone with PKU can not have a child
4.If a child is born with PKU and it is not treated it can lead to brain damage in the first few
months of life
Rationale: An individual with PKU that wants to have a baby can they just have to closely monitor
their diet and maintain a low phenylalanine diet in order to keep them and their baby healthy.
(Hockenberry, 2019).

11. References
Hockenberry, M.J., & Wilson, D., & McCampbell, L. (2019). Wong’s nursing care of
infants and children (11th ed.). St. Louis: Mosby.