Tyrosinemia Type 1: An Overview of Nursing Care

Elizabeth Barnby, DNP, ACNP-BC, RN

Disclosures

Pediatr Nurs. 2014;40(2):61-66. 

In This Article

Treatment

Children with TT1 must maintain strict metabolic control of their disease. Parents play a key role in metabolic control by maintaining dietary restriction of protein consumption and avoidance of protein catabolism (Ashorn, Pitkanen, Salo, & Heikinheimo, 2006). Typical treatment requires intensive developmentally appropriate patient and family education. An age-appropriate guide is useful to address these educational needs (see Table 1).

Avoiding protein catabolism is difficult in the presence of an acute viral illness. When unable to eat, the body naturally breaks down protein stores to maintain homeostasis. The breakdown of protein causes the level of amino acid tyrosine to rise and results in a metabolic crisis (Claudius, Fluharty, & Boles, 2005).

During fasting, the body produces ketones. Urine ketones can be used as a metabolic indicator of protein catabolism. Ketones are a breakdown product of fatty acid metabolism. Ketones in the urine should be managed as an emergency. When ketotic, it is essential for the child to consume glucose to prevent protein catabolism (Claudius et al., 2005). If the child is unable, intravenous therapy can prevent complications associated with increased tyrosine levels. An antiemetic may be ordered if nausea and vomiting are present. Antiemetics can also be prescribed as needed to prevent future episodes of ketosis and adverse outcomes (Fedorowicz, Jagannath, & Carter, 2011).

Without the steady consumption of fat and carbohydrates, muscle protein is metabolized and tyrosine levels rise. As tyrosine levels increase, toxic metabolites build up. One toxic metabolite is succinylacetone, which causes ALAD porphyria in a complex biochemical process that interferes with heme metabolism. This biochemical interaction results in neurologic crisis (Anderson et al., 2005).

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