The Journal of the Arkansas Medical Society Med Journal April 2019 Final 2 | Page 13

AFMC: A CLOSER LOOK AT QUALIT Y to determine the need for thyroid hormone replacement. Thyroid ultrasound and nuclear scan are the two most commonly utilized imaging modalities. Patients with an initial TSH level greater than 40 mIU/ml on the NBS should have thyroid hormone replacement initiated with levothyroxine (L-T4). Treatment should begin as soon as confirmatory serum tests have been drawn, even before results are available. 1,2 In a recent survey of Arkansas primary care providers (n=75), two-thirds stated they prefer to wait for confirmatory testing results before beginning treatment because results are usually available the same day. Treatment goals are to normalize TSH and Free T4 as soon as possible, start treatment prior to three weeks of life and keep TSH within the lower half and Free T4 in the upper half of the normal range. Children whose levels were normalized by one to two weeks scored higher on indices of visual memory, attention and math skills, compared to those who took longer to normalize their levels. 3 An L-T4 dose of 10-15 mcg/kg/day (max. dose 50 mcg/day) is the recom- mended initial oral replacement dose. Individual differences and co-morbidities should be considered for initial dose selection. Frequent clinical and biochemical assessments are needed for optimal manage- ment. Although normalization of TSH may take up to four weeks, Free T4 level should become normal within days of treatment. Measure TSH and Free T4 in two weeks to ensure good response to treatment and timely adjustment of the medica- tion dose. Avoid overtreatment as it may result in sustained tachycardia, jitteriness, impaired feeding, poor weight gain, premature synostosis and undue advancement of bone age if not recognized early. Con- sultation with a pediatric endocri- nologist is strongly encouraged to improve patients’ outcome. Only tablet forms of L-T4 should be used. No FDA-approved liquid formulations are available in the United States. There are concerns for reliable dosing of suspension forms prepared by individual pharmacies. Iron, calcium, fiber and soy products should be avoided when administering L-T4 due to interference with drug absorption. L-T4 should be crushed and mixed with small volume of breast milk, formula or water, and given directly into the infant’s mouth. Inadequate thyroid hormone replacement within the first three years of life may result in irreversible neurodevelopmental outcomes. Highest risk factors for developmental disability are severe hypothyroidism at birth and delayed diagnosis. NBS has largely eliminated delays in timely diagnosis. However, although rare, false negative results in the NBS are still possible (i.e., preterm or multiple births). Serum thyroid hormone measurement should always be carried out if clinical concerns exist, even if the NBS was normal. Thyroid hormone is essential for neuronal cell migration, which peaks in the third trimester and continues for three years of post- natal life. Children with CH must be closely monitored for compliance and age appropriate growth and development at each visit. Poor compliance alone is an independent risk factor for worse outcome. Early identification and timely intervention are key to improving outcomes. Ages and Stages Questionnaire (ASQ) is a validated developmental screening tool and superior to surveillance alone. At-risk cases (severe hypothyroidism at birth, TSH elevation while on therapy) should be more closely monitored. Use ASQ to screen children’s gross-motor, fine- motor, communication, personal- social and problem-solving skills from newborn until age 5. Hearing tests should be carried out at birth and as needed if speech delay is suspected or diagnosed. 4 Targeted training and personalized education may be needed especially if academic success and psychomotor development is a concern. s Drs. Wang and Tas are with the Division of Endocrinology and Diabetes, Arkansas Children’s Hospital in Little Rock. REFERENCES 1. Léger J, Olivieri A, Donaldson M, et al. European society for paediatric endocrinology consensus guidelines on screening, diagnosis, and management of congenital hypothyroidism. Horm Res Paediatr. 2014. doi:10.1159/000358198 2. American Academy of Pediatrics S on E and C on G, Rose SR, Section on Endocrinology and Committee on Genetics, American Thyroid Association L, et al. Update of Newborn Screening and Therapy for Congenital Hypothyroidism. Pediatrics. 2006. doi:10.1542/peds.2006-0915 3. Selva KA, Harper A, Downs A, et.al. Neurodevelopmental outcomes in congenital hypothyroidism: Comparison of initial T4 dose and time to reach target T4 and TSH. J Pediatr. 2005. doi:10.1016/j. jpeds.2005.07.024 4. Léger J. Congenital hypothyroidism: A clinical update of long-term outcome in young adults. Eur J Endocrinol. 2015. doi:10.1530/EJE-14-0777 AFMC WORKS COLLABORATIVELY WITH PROVIDERS, COMMUNITY GROUPS AND OTHER STAKEHOLDERS TO PROMOTE THE QUALITY OF CARE IN ARKANSAS THROUGH EDUCATION AND EVALUATION. FOR MORE INFORMATION ABOUT AFMC QUALITY IMPROVEMENT PROJECTS, CALL 1-877-375-5700 OR VISIT AFMC.ORG. APRIL 2019 NUMBER 10 APRIL 2019 • 229