Treatment Guidelines: New Patients
Objective 1: Establish diagnosis and initiate contact with metabolic team.
- Referral from Newborn Screening Coordinator is received by metabolic clinic.
- Quantitative blood phenylalanine and tyrosine levels are measured to confirm diagnosis.
- Urine is collected for biopterin assay and blood for dihydropteridine reductase determination. (Samples are sent to an outside lab.)
- Initial appointment with metabolic team is made.
- Use the Checklist for Families New to the PKU Clinic to guide initial visits.
Objective 2: Obtain baseline data at first clinic visit.
- Document birth weight, length, OFC.
- Measure weight length, OFC; plot on appropriate growth charts.
- Draw blood for phenylalanine, tyrosine.
- Document feeding history, e.g., formula, breastmilk, and baseline intakes.
- If studies not complete, collect urine for biopterin assay and blood for dihydropteridine reductase determination.
Objective 3: Initiate treatment at first clinic visit. Adjust blood phenylalanine levels to achieve treatment goal of phenylalanine concentrations of 1-6 mg/dL.
- If phenylalanine level >20 mg/dl:
- Phenylalanine-free formula alone until blood phenylalanine level <10 mg/dL, regardless of previous manner of feeding.
- Monitor blood phenylalanine levels every other day.
- If phenylalanine level 10-20 mg/dL:
- Phenylalanine-free formula alone (for 2-5 days) to bring level to <10 mg/dL, regardless of previous manner of feeding.
- After level is <10 mg/dL, negotiate with breast-feeding mother about her wishes regarding continuing breast-feeding with supplemental phenylalanine-free formula or bottle feeding only.
- If phenylalanine level 6-10 mg/dL and mother is breast-feeding, support breast-feeding and introduce phenylalanine-free formula to bring level to 1-6 mg/dL If phenylalanine level 6-10 mg/dL and infant is on standard formula, introduce phenylalanine-free formula to bring level to 1-6 mg/dL
Objective 4: Monitor blood phenylalanine levels until treatment goal (1-6 mg/dL) is reached.
- While blood level is decreasing, measure blood phenylalanine and tyrosine every other day.
- Establish baseline intake of 100-120 kcal/kg and 2.0-3.5 g protein/kg.
Objective 5: Continue to monitor when blood phenylalanine levels reach treatment goal (1-6 mg/dL).
- Establish baseline intake of 100-120 kcal/kg, 2.0-3.5 g protein/kg, and 35-60 mg phenylalanine/kg. Introduce breastmilk or infant formula as needed to stabilize blood phenylalanine levels.
- Monitor blood phenylalanine and tyrosine weekly.
- Measure weight weekly. Monitor growth rate.
- Monitor intake: daily log of formula/breastmilk intake. Monitor phenylalanine, protein, and energy intakes.
- Document state of health and wellness.
Objective 6: Continue to monitor when blood phenylalanine levels have stabilized (4 serial determinations) at treatment goal (1-6 mg/dL).
- Measure blood phenylalanine and tyrosine levels monthly.
- Measure weight and length monthly. Monitor growth rate.
- Monitor intake: daily log of formula/breastmilk intake. Monitor phenylalanine, protein, and energy intakes.
- Document state of health and wellness.
Objective 7: Adjust treatment as necessary during illness.
- Adjust phenylalanine intake as necessary.
- Monitor blood phenylalanine levels more frequently until levels are stabilized.